path: root/docs/apex/APEX-User-Manual.rst

.. This work is licensed under a Creative Commons Attribution 4.0 International License.
.. http://creativecommons.org/licenses/by/4.0


APEX User Manual
****************

.. contents::
    :depth: 3

Installation of Apex
^^^^^^^^^^^^^^^^^^^^

Requirements
------------

            .. container:: paragraph

               APEX is 100% written in Java and runs on any platform
               that supports a JVM, e.g. Windows, Unix, Cygwin. Some
               APEX applications (such as the monitoring application)
               come as web archives, they do require a war-capable web
               server installed.

Installation Requirements
#########################

               .. container:: ulist

                  -  Downloaded distribution: JAVA runtime environment
                     (JRE, Java 11 or later, APEX is tested with the
                     OpenJDK Java)

                  -  Building from source: JAVA development kit (JDK,
                     Java 11 or later, APEX is tested with the OpenJDK
                     Java)

                  -  A web archive capable webserver, for instance for
                     the monitoring application

                     .. container:: ulist

                        -  for instance `Apache
                           Tomcat <https://tomcat.apache.org/>`__

                  -  Sufficient rights to install APEX on the system

                  -  Installation tools depending on the installation
                     method used:

                     .. container:: ulist

                        -  ZIP to extract from a ZIP distribution

                           .. container:: ulist

                              -  Windows for instance
                                 `7Zip <http://www.7-zip.org/>`__

                        -  TAR and GZ to extract from that TAR.GZ
                           distribution

                           .. container:: ulist

                              -  Windows for instance
                                 `7Zip <http://www.7-zip.org/>`__

                        -  DPKG to install from the DEB distribution

                           .. container:: ulist

                              -  Install: ``sudo apt-get install dpkg``

Feature Requirements
####################

               .. container:: paragraph

                  APEX supports a number of features that require extra
                  software being installed.

               .. container:: ulist

                  -  `Apache Kafka <https://kafka.apache.org/>`__ to
                     connect APEX to a Kafka message bus

                  -  `Hazelcast <https://hazelcast.com/>`__ to use
                     distributed hash maps for context

                  -  `Infinispan <http://infinispan.org/>`__ for
                     distributed context and persistence

                  -  `Docker <https://www.docker.com/>`__ to run APEX
                     inside a Docker container

Build (Install from Source) Requirements
########################################

               .. container:: paragraph

                  Installation from source requires a few development
                  tools

               .. container:: ulist

                  -  GIT to retrieve the source code

                  -  Java SDK, Java version 8 or later

                  -  Apache Maven 3 (the APEX build environment)

Get the APEX Source Code
------------------------

            .. container:: paragraph

               The first APEX source code was hosted on Github in
               January 2018. By the end of 2018, APEX was added as a
               project in the ONAP Policy Framework, released later in
               the ONAP Casablanca release.

            .. container:: paragraph

               The APEX source code is hosted in ONAP as project APEX.
               The current stable version is in the master branch.
               Simply clone the master branch from ONAP using HTTPS.

            .. container:: listingblock

               .. container:: content

                  .. code::
                     :number-lines:

                     git clone https://gerrit.onap.org/r/policy/apex-pdp

Build APEX
----------

   .. container:: paragraph

      The examples in this document assume that the APEX source
      repositories are cloned to:

   .. container:: ulist

      -  Unix, Cygwin: ``/usr/local/src/apex-pdp``

      -  Windows: ``C:\dev\apex-pdp``

      -  Cygwin: ``/cygdrive/c/dev/apex-pdp``

   .. important::
      A Build requires ONAP Nexus
      APEX has a dependency to ONAP parent projects. You might need to adjust your Maven M2 settings. The most current
      settings can be found in the ONAP oparent repo: `Settings <https://git.onap.org/oparent/plain/settings.xml>`__.

   .. important::
      A Build needs Space
      Building APEX requires approximately 2-3 GB of hard disc space, 1 GB for the actual build with full
      distribution and 1-2 GB for the downloaded dependencies

   .. important::
      A Build requires Internet (for first build)
      During the build, several (a lot) of Maven dependencies will be downloaded and stored in the configured local Maven
      repository. The first standard build (and any first specific build) requires Internet access to download those
      dependencies.

   .. container:: paragraph

      Use Maven to for a standard build without any tests.

      +-------------------------------------------------------+--------------------------------------------------------+
      | Unix, Cygwin                                          | Windows                                                |
      +=======================================================+========================================================+
      | .. container::                                        | .. container::                                         |
      |                                                       |                                                        |
      |    .. container:: content                             |    .. container:: content                              |
      |                                                       |                                                        |
      |       .. code::                                       |       .. code::                                        |
      |         :number-lines:                                |         :number-lines:                                 |
      |                                                       |                                                        |
      |         # cd /usr/local/src/apex-pdp                  |          >c:                                           |
      |         # mvn clean install -Pdocker -DskipTests      |          >cd \dev\apex                                 |
      |                                                       |          >mvn clean install -Pdocker -DskipTests       |
      +-------------------------------------------------------+--------------------------------------------------------+

.. container:: paragraph

   The build takes 2-3 minutes on a standard development laptop. It
   should run through without errors, but with a lot of messages from
   the build process.

.. container:: paragraph

   When Maven is finished with the build, the final screen should look
   similar to this (omitting some ``success`` lines):

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        [INFO] tools .............................................. SUCCESS [  0.248 s]
        [INFO] tools-common ....................................... SUCCESS [  0.784 s]
        [INFO] simple-wsclient .................................... SUCCESS [  3.303 s]
        [INFO] model-generator .................................... SUCCESS [  0.644 s]
        [INFO] packages ........................................... SUCCESS [  0.336 s]
        [INFO] apex-pdp-package-full .............................. SUCCESS [01:10 min]
        [INFO] Policy APEX PDP - Docker build 2.0.0-SNAPSHOT ...... SUCCESS [ 10.307 s]
        [INFO] ------------------------------------------------------------------------
        [INFO] BUILD SUCCESS
        [INFO] ------------------------------------------------------------------------
        [INFO] Total time: 03:43 min
        [INFO] Finished at: 2018-09-03T11:56:01+01:00
        [INFO] ------------------------------------------------------------------------

.. container:: paragraph

   The build will have created all artifacts required for an APEX
   installation. The following example show how to change to the target
   directory and how it should look like.

+----------------------------------------------------------------------------------------------------------------+
| Unix, Cygwin                                                                                                   |
+================================================================================================================+
| .. container:: content                                                                                         |
|                                                                                                                |
| .. container:: listingblock                                                                                    |
|                                                                                                                |
| .. container:: content                                                                                         |
|                                                                                                                |
| .. code::                                                                                                      |
|                                                                                                                |
| :number-lines:                                                                                                 |
|                                                                                                                |
| -rwxrwx---+ 1 esvevan Domain Users       772 Sep  3 11:55 apex-pdp-package-full_2.0.0~SNAPSHOT_all.changes*    |
| -rwxrwx---+ 1 esvevan Domain Users 146328082 Sep  3 11:55 apex-pdp-package-full-2.0.0-SNAPSHOT.deb*            |
| -rwxrwx---+ 1 esvevan Domain Users     15633 Sep  3 11:54 apex-pdp-package-full-2.0.0-SNAPSHOT.jar*            |
| -rwxrwx---+ 1 esvevan Domain Users 146296819 Sep  3 11:55 apex-pdp-package-full-2.0.0-SNAPSHOT-tarball.tar.gz* |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 archive-tmp/                                         |
| -rwxrwx---+ 1 esvevan Domain Users        89 Sep  3 11:54 checkstyle-cachefile*                                |
| -rwxrwx---+ 1 esvevan Domain Users     10621 Sep  3 11:54 checkstyle-checker.xml*                              |
| -rwxrwx---+ 1 esvevan Domain Users       584 Sep  3 11:54 checkstyle-header.txt*                               |
| -rwxrwx---+ 1 esvevan Domain Users        86 Sep  3 11:54 checkstyle-result.xml*                               |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 classes/                                             |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 dependency-maven-plugin-markers/                     |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 etc/                                                 |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 examples/                                            |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:55 install_hierarchy/                                   |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 maven-archiver/                                      |
+----------------------------------------------------------------------------------------------------------------+

+-----------------------------------------------------------------------------------------+
| Windows                                                                                 |
+=========================================================================================+
| .. container::                                                                          |
|                                                                                         |
| .. container:: listingblock                                                             |
|                                                                                         |
| .. container:: content                                                                  |
|                                                                                         |
| .. code::                                                                               |
| :number-lines:                                                                          |
|                                                                                         |
| 03/09/2018  11:55    <DIR>          .                                                   |
| 03/09/2018  11:55    <DIR>          ..                                                  |
| 03/09/2018  11:55       146,296,819 apex-pdp-package-full-2.0.0-SNAPSHOT-tarball.tar.gz |
| 03/09/2018  11:55       146,328,082 apex-pdp-package-full-2.0.0-SNAPSHOT.deb            |
| 03/09/2018  11:54            15,633 apex-pdp-package-full-2.0.0-SNAPSHOT.jar            |
| 03/09/2018  11:55               772 apex-pdp-package-full_2.0.0~SNAPSHOT_all.changes    |
| 03/09/2018  11:54    <DIR>          archive-tmp                                         |
| 03/09/2018  11:54                89 checkstyle-cachefile                                |
| 03/09/2018  11:54            10,621 checkstyle-checker.xml                              |
| 03/09/2018  11:54               584 checkstyle-header.txt                               |
| 03/09/2018  11:54                86 checkstyle-result.xml                               |
| 03/09/2018  11:54    <DIR>          classes                                             |
| 03/09/2018  11:54    <DIR>          dependency-maven-plugin-markers                     |
| 03/09/2018  11:54    <DIR>          etc                                                 |
| 03/09/2018  11:54    <DIR>          examples                                            |
| 03/09/2018  11:55    <DIR>          install_hierarchy                                   |
| 03/09/2018  11:54    <DIR>          maven-archiver                                      |
| 8 File(s)    292,652,686 bytes                                                          |
| 9 Dir(s)  14,138,720,256 bytes free                                                     |
+-----------------------------------------------------------------------------------------+

Install APEX
------------

   .. container:: paragraph

      APEX can be installed in different ways:

   .. container:: ulist

      -  Unix: automatically using ``dpkg`` from
         ``.deb`` archive

      -  Windows, Unix, Cygwin: manually from a ``.tar.gz`` archive

      -  Windows, Unix, Cygwin: build from source using Maven, then
         install manually

Install with DPKG
#################

      .. container:: paragraph

         You can get the APEX debian package from the
         `ONAP Nexus Repository <https://nexus.onap.org/content/groups/public/org/onap/policy/apex-pdp/packages/apex-pdp-package-full/>`__.

         The install distributions of APEX automatically install the
         system. The installation directory is
         ``/opt/app/policy/apex-pdp``. Log files are located in
         ``/var/log/onap/policy/apex-pdp``. The latest APEX version will
         be available as ``/opt/app/policy/apex-pdp/apex-pdp``.

      .. container:: paragraph

         For the installation, a new user ``apexuser`` and a new group
         ``apexuser`` will be created. This user owns the installation
         directories and the log file location. The user is also used by
         the standard APEX start scripts to run APEX with this user’s
         permissions.

+--------------------------------------------------------------------------+
| DPKG Installation                                                        |
+==========================================================================+
| .. container::                                                           |
|                                                                          |
| .. container:: listingblock                                              |
|                                                                          |
| .. container:: content                                                   |
|                                                                          |
| .. code::                                                                |
| :number-lines:                                                           |
|                                                                          |
| # sudo dpkg -i apex-pdp-package-full-2.0.0-SNAPSHOT.deb                  |
| Selecting previously unselected package apex-uservice.                   |
| (Reading database ... 288458 files and directories currently installed.) |
| Preparing to unpack apex-pdp-package-full-2.0.0-SNAPSHOT.deb ...         |
| ********************preinst*******************                           |
| arguments install                                                        |
| **********************************************                           |
| creating group apexuser . . .                                            |
| creating user apexuser . . .                                             |
| Unpacking apex-uservice (2.0.0-SNAPSHOT) ...                             |
| Setting up apex-uservice (2.0.0-SNAPSHOT) ...                            |
| ********************postinst****************                             |
| arguments configure                                                      |
| ***********************************************                          |
+--------------------------------------------------------------------------+

.. container:: paragraph

   Once the installation is finished, APEX is fully installed and ready
   to run.

Install Manually from Archive (Unix, Cygwin)
############################################

   .. container:: paragraph

      You can download a ``tar.gz`` archive from the
      `ONAP Nexus Repository <https://nexus.onap.org/content/groups/public/org/onap/policy/apex-pdp/packages/apex-pdp-package-full/>`__.

      Create a directory where APEX
      should be installed. Extract the ``tar`` archive. The following
      example shows how to install APEX in ``/opt/apex`` and create a
      link to ``/opt/apex/apex`` for the most recent installation.

   .. container:: listingblock

      .. container:: content

         .. code::
            :number-lines:

            # cd /opt
            # mkdir apex
            # cd apex
            # mkdir apex-full-2.0.0-SNAPSHOT
            # tar xvfz ~/Downloads/apex-pdp-package-full-2.0.0-SNAPSHOT.tar.gz -C apex-full-2.0.0-SNAPSHOT
            # ln -s apex apex-pdp-package-full-2.0.0-SNAPSHOT

Install Manually from Archive (Windows, 7Zip, GUI)
##################################################

   .. container:: paragraph

      You can download a ``tar.gz`` archive from the
      `ONAP Nexus Repository <https://nexus.onap.org/content/groups/public/org/onap/policy/apex-pdp/packages/apex-pdp-package-full/>`__.

      Copy the ``tar.gz`` file into the install
      folder (in this example ``C:\apex``). Assuming you are using 7Zip,
      right click on the file and extract the ``tar`` archive. Note: the
      screenshots might show an older version than you have.

   .. container:: imageblock

      .. container:: content

         |Extract the TAR archive|

   .. container:: paragraph

      The right-click on the new created TAR file and extract the actual
      APEX distribution.

   .. container:: imageblock

      .. container:: content

         |Extract the APEX distribution|

   .. container:: paragraph

      Inside the new APEX folder you see the main directories: ``bin``,
      ``etc``, ``examples``, ``lib``, and ``war``

   .. container:: paragraph

      Once extracted, please rename the created folder to
      ``apex-full-2.0.0-SNAPSHOT``. This will keep the directory name in
      line with the rest of this documentation.

Install Manually from Archive (Windows, 7Zip, CMD)
##################################################

   .. container:: paragraph

      You can download a ``tar.gz`` archive from the
      `ONAP Nexus Repository <https://nexus.onap.org/content/groups/public/org/onap/policy/apex-pdp/packages/apex-pdp-package-full/>`__.

      Copy the ``tar.gz`` file into the install
      folder (in this example ``C:\apex``). Start ``cmd``, for instance
      typing ``Windows+R`` and then ``cmd`` in the dialog. Assuming
      ``7Zip`` is installed in the standard folder, simply run the
      following commands (for APEX version 2.0.0-SNAPSHOT full
      distribution)

   .. container:: listingblock

      .. container:: content

         .. code::
           :number-lines:

            >c:
            >cd \apex
            >"\Program Files\7-Zip\7z.exe" x apex-pdp-package-full-2.0.0-SNAPSHOT.tar.gz -so | "\Program Files\7-Zip\7z.exe" x -aoa -si -ttar -o"apex-full-2.0.0-SNAPSHOT"

.. container:: paragraph

   APEX is now installed in the folder
   ``C:\apex\apex-full-2.0.0-SNAPSHOT``.

Build from Source
-----------------

Build and Install Manually (Unix, Windows, Cygwin)
##################################################

      .. container:: paragraph

         Clone the APEX GIT repositories into a directory. Go to that
         directory. Use Maven to build APEX (all details on building
         APEX from source can be found in *APEX HowTo: Build*). Install
         from the created artifacts (``rpm``, ``deb``, ``tar.gz``, or
         copying manually).

      .. container:: paragraph

         The following example shows how to build the APEX system,
         without tests (``-DskipTests``) to safe some time. It assumes
         that the APX GIT repositories are cloned to:

      .. container:: ulist

         -  Unix, Cygwin: ``/usr/local/src/apex``

         -  Windows: ``C:\dev\apex``

         +-------------------------------------------------------+--------------------------------------------------------+
         | Unix, Cygwin                                          | Windows                                                |
         +=======================================================+========================================================+
         | .. container::                                        | .. container::                                         |
         |                                                       |                                                        |
         |    .. container:: content                             |    .. container:: content                              |
         |                                                       |                                                        |
         |       .. code::                                       |       .. code::                                        |
         |         :number-lines:                                |         :number-lines:                                 |
         |                                                       |                                                        |
         |         # cd /usr/local/src/apex                      |         >c:                                            |
         |         # mvn clean install -Pdocker -DskipTests      |         >cd \dev\apex                                  |
         |                                                       |         >mvn clean install -Pdocker -DskipTests        |
         +-------------------------------------------------------+--------------------------------------------------------+

.. container:: paragraph

   The build takes about 2 minutes without test and about 4-5 minutes
   with tests on a standard development laptop. It should run through
   without errors, but with a lot of messages from the build process. If
   build with tests (i.e. without ``-DskipTests``), there will be error
   messages and stack trace prints from some tests. This is normal, as
   long as the build finishes successful.

.. container:: paragraph

   When Maven is finished with the build, the final screen should look
   similar to this (omitting some ``success`` lines):

.. container:: listingblock

   .. container:: content

      .. code::
         :number-lines:

         [INFO] tools .............................................. SUCCESS [  0.248 s]
         [INFO] tools-common ....................................... SUCCESS [  0.784 s]
         [INFO] simple-wsclient .................................... SUCCESS [  3.303 s]
         [INFO] model-generator .................................... SUCCESS [  0.644 s]
         [INFO] packages ........................................... SUCCESS [  0.336 s]
         [INFO] apex-pdp-package-full .............................. SUCCESS [01:10 min]
         [INFO] Policy APEX PDP - Docker build 2.0.0-SNAPSHOT ...... SUCCESS [ 10.307 s]
         [INFO] ------------------------------------------------------------------------
         [INFO] BUILD SUCCESS
         [INFO] ------------------------------------------------------------------------
         [INFO] Total time: 03:43 min
         [INFO] Finished at: 2018-09-03T11:56:01+01:00
         [INFO] ------------------------------------------------------------------------

.. container:: paragraph

   The build will have created all artifacts required for an APEX
   installation. The following example show how to change to the target
   directory and how it should look like.

+----------------------------------------------------------------------------------------------------------------+
| Unix, Cygwin                                                                                                   |
+================================================================================================================+
| .. container::                                                                                                 |
|                                                                                                                |
| .. container:: listingblock                                                                                    |
|                                                                                                                |
| .. code::                                                                                                      |
| :number-lines:                                                                                                 |
|                                                                                                                |
| # cd packages/apex-pdp-package-full/target                                                                     |
| # ls -l                                                                                                        |
| -rwxrwx---+ 1 esvevan Domain Users       772 Sep  3 11:55 apex-pdp-package-full_2.0.0~SNAPSHOT_all.changes*    |
| -rwxrwx---+ 1 esvevan Domain Users 146328082 Sep  3 11:55 apex-pdp-package-full-2.0.0-SNAPSHOT.deb*            |
| -rwxrwx---+ 1 esvevan Domain Users     15633 Sep  3 11:54 apex-pdp-package-full-2.0.0-SNAPSHOT.jar*            |
| -rwxrwx---+ 1 esvevan Domain Users 146296819 Sep  3 11:55 apex-pdp-package-full-2.0.0-SNAPSHOT-tarball.tar.gz* |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 archive-tmp/                                         |
| -rwxrwx---+ 1 esvevan Domain Users        89 Sep  3 11:54 checkstyle-cachefile*                                |
| -rwxrwx---+ 1 esvevan Domain Users     10621 Sep  3 11:54 checkstyle-checker.xml*                              |
| -rwxrwx---+ 1 esvevan Domain Users       584 Sep  3 11:54 checkstyle-header.txt*                               |
| -rwxrwx---+ 1 esvevan Domain Users        86 Sep  3 11:54 checkstyle-result.xml*                               |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 classes/                                             |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 dependency-maven-plugin-markers/                     |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 etc/                                                 |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 examples/                                            |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:55 install_hierarchy/                                   |
| drwxrwx---+ 1 esvevan Domain Users         0 Sep  3 11:54 maven-archiver/                                      |
+----------------------------------------------------------------------------------------------------------------+

+-----------------------------------------------------------------------------------------+
| Windows                                                                                 |
+=========================================================================================+
| .. container::                                                                          |
|                                                                                         |
| .. container:: listingblock                                                             |
|                                                                                         |
| .. code::                                                                               |
| :number-lines:                                                                          |
|                                                                                         |
| >cd packages\apex-pdp-package-full\target                                               |
| >dir                                                                                    |
| 03/09/2018  11:55    <DIR>          .                                                   |
| 03/09/2018  11:55    <DIR>          ..                                                  |
| 03/09/2018  11:55       146,296,819 apex-pdp-package-full-2.0.0-SNAPSHOT-tarball.tar.gz |
| 03/09/2018  11:55       146,328,082 apex-pdp-package-full-2.0.0-SNAPSHOT.deb            |
| 03/09/2018  11:54            15,633 apex-pdp-package-full-2.0.0-SNAPSHOT.jar            |
| 03/09/2018  11:55               772 apex-pdp-package-full_2.0.0~SNAPSHOT_all.changes    |
| 03/09/2018  11:54    <DIR>          archive-tmp                                         |
| 03/09/2018  11:54                89 checkstyle-cachefile                                |
| 03/09/2018  11:54            10,621 checkstyle-checker.xml                              |
| 03/09/2018  11:54               584 checkstyle-header.txt                               |
| 03/09/2018  11:54                86 checkstyle-result.xml                               |
| 03/09/2018  11:54    <DIR>          classes                                             |
| 03/09/2018  11:54    <DIR>          dependency-maven-plugin-markers                     |
| 03/09/2018  11:54    <DIR>          etc                                                 |
| 03/09/2018  11:54    <DIR>          examples                                            |
| 03/09/2018  11:55    <DIR>          install_hierarchy                                   |
| 03/09/2018  11:54    <DIR>          maven-archiver                                      |
| 8 File(s)    292,652,686 bytes                                                          |
| 9 Dir(s)  14,138,720,256 bytes free                                                     |
+-----------------------------------------------------------------------------------------+

.. container:: paragraph

   Now, take the ``.deb`` or the ``.tar.gz`` file and install APEX.
   Alternatively, copy the content of the folder ``install_hierarchy``
   to your APEX directory.

Installation Layout
-------------------

   .. container:: paragraph

      A full installation of APEX comes with the following layout.

   .. container:: listingblock

      .. container:: content

::

            $APEX_HOME
                ├───bin             (1)
                ├───etc             (2)
                │   ├───editor
                │   ├───hazelcast
                │   ├───infinispan
                │   └───META-INF
                ├───examples            (3)
                │   ├───config          (4)
                │   ├───docker          (5)
                │   ├───events          (6)
                │   ├───html            (7)
                │   ├───models          (8)
                │   └───scripts         (9)
                ├───lib             (10)
                │   └───applications        (11)
                └───war             (12)

   .. container:: colist arabic

      +-----------------------------------+-----------------------------------+
      | **1**                             | binaries, mainly scripts (bash    |
      |                                   | and bat) to start the APEX engine |
      |                                   | and applications                  |
      +-----------------------------------+-----------------------------------+
      | **2**                             | configuration files, such as      |
      |                                   | logback (logging) and third party |
      |                                   | library configurations            |
      +-----------------------------------+-----------------------------------+
      | **3**                             | example policy models to get      |
      |                                   | started                           |
      +-----------------------------------+-----------------------------------+
      | **4**                             | configurations for the examples   |
      |                                   | (with sub directories for         |
      |                                   | individual examples)              |
      +-----------------------------------+-----------------------------------+
      | **5**                             | Docker files and additional       |
      |                                   | Docker instructions for the       |
      |                                   | exampples                         |
      +-----------------------------------+-----------------------------------+
      | **6**                             | example events for the examples   |
      |                                   | (with sub directories for         |
      |                                   | individual examples)              |
      +-----------------------------------+-----------------------------------+
      | **7**                             | HTML files for some examples,     |
      |                                   | e.g. the Decisionmaker example    |
      +-----------------------------------+-----------------------------------+
      | **8**                             | the policy models, generated for  |
      |                                   | each example (with sub            |
      |                                   | directories for individual        |
      |                                   | examples)                         |
      +-----------------------------------+-----------------------------------+
      | **9**                             | additional scripts for the        |
      |                                   | examples (with sub directories    |
      |                                   | for individual examples)          |
      +-----------------------------------+-----------------------------------+
      | **10**                            | the library folder with all Java  |
      |                                   | JAR files                         |
      +-----------------------------------+-----------------------------------+
      | **11**                            | applications, also known as jar   |
      |                                   | with dependencies (or fat jars),  |
      |                                   | individually deployable           |
      +-----------------------------------+-----------------------------------+
      | **12**                            | WAR files for web applications    |
      +-----------------------------------+-----------------------------------+

System Configuration
--------------------

   .. container:: paragraph

      Once APEX is installed, a few configurations need to be done:

   .. container:: ulist

      -  Create an APEX user and an APEX group (optional, if not
         installed using RPM and DPKG)

      -  Create environment settings for ``APEX_HOME`` and
         ``APEX_USER``, required by the start scripts

      -  Change settings of the logging framework (optional)

      -  Create directories for logging, required (execution might fail
         if directories do not exist or cannot be created)

APEX User and Group
###################

      .. container:: paragraph

         On smaller installations and test systems, APEX can run as any
         user or group.

      .. container:: paragraph

         However, if APEX is installed in production, we strongly
         recommend you set up a dedicated user for running APEX. This
         will isolate the execution of APEX to that user. We recommend
         you use the userid ``apexuser`` but you may use any user you
         choose.

      .. container:: paragraph

         The following example, for UNIX, creates a group called
         ``apexuser``, an APEX user called ``apexuser``, adds the group
         to the user, and changes ownership of the APEX installation to
         the user. Substitute ``<apex-dir>`` with the directory where
         APEX is installed.

         .. container:: listingblock

            .. container:: content

               .. code::
                  :number-lines:

                  # sudo groupadd apexuser
                  # sudo useradd -g apexuser apexuser
                  # sudo chown -R apexuser:apexuser <apex-dir>

.. container:: paragraph

   For other operating systems please consult your manual or system
   administrator.

Environment Settings: APEX_HOME and APEX_USER
#############################################

   .. container:: paragraph

      The provided start scripts for APEX require two environment
      variables being set:

   .. container:: ulist

      -  ``APEX_USER`` with the user under whos name and permission APEX
         should be started (Unix only)

      -  ``APEX_HOME`` with the directory where APEX is installed (Unix,
         Windows, Cygwin)

   .. container:: paragraph

      The first row in the following table shows how to set these
      environment variables temporary (assuming the user is
      ``apexuser``). The second row shows how to verify the settings.
      The last row explains how to set those variables permanently.

   +------------------------------------------------+---------------------------------------------------------+
   | Unix, Cygwin (bash/tcsh)                       | Windows                                                 |
   +================================================+=========================================================+
   | .. container::                                 | .. container::                                          |
   |                                                |                                                         |
   |    .. container:: content                      |    .. container:: content                               |
   |                                                |                                                         |
   |       .. code::                                |       .. code::                                         |
   |          :number-lines:                        |         :number-lines:                                  |
   |                                                |                                                         |
   |          # export APEX_USER=apexuser           |         >set APEX_HOME=C:\apex\apex-full-2.0.0-SNAPSHOT |
   |          # cd /opt/app/policy/apex-pdp         |                                                         |
   |          # export APEX_HOME=`pwd`              |                                                         |
   |                                                |                                                         |
   +------------------------------------------------+                                                         |
   | .. container::                                 |                                                         |
   |                                                |                                                         |
   |    .. container:: content                      |                                                         |
   |                                                |                                                         |
   |       .. code::tcsh                            |                                                         |
   |          :number-lines:                        |                                                         |
   |                                                |                                                         |
   |          # setenv APEX_USER apexuser           |                                                         |
   |          # cd /opt/app/policy/apex-pdp         |                                                         |
   |          # setenv APEX_HOME `pwd`              |                                                         |
   |                                                |                                                         |
   +------------------------------------------------+---------------------------------------------------------+
   | .. container::                                 | .. container::                                          |
   |                                                |                                                         |
   |    .. container:: content                      |    .. container:: content                               |
   |                                                |                                                         |
   |       .. code::                                |       .. code::                                         |
   |          :number-lines:                        |          :number-lines:                                 |
   |                                                |                                                         |
   |          # env | grep APEX                     |          >set APEX_HOME                                 |
   |          # APEX_USER=apexuser                  |          APEX_HOME=\apex\apex-full-2.0.0-SNAPSHOT       |
   |          # APEX_HOME=/opt/app/policy/apex-pdp  |                                                         |
   |                                                |                                                         |
   +------------------------------------------------+---------------------------------------------------------+

Making Environment Settings Permanent (Unix, Cygwin)
====================================================

   .. container:: paragraph

      For a per-user setting, edit the a user’s ``bash`` or ``tcsh``
      settings in ``~/.bashrc`` or ``~/.tcshrc``. For system-wide
      settings, edit ``/etc/profiles`` (requires permissions).

Making Environment Settings Permanent (Windows)
===============================================

   .. container:: paragraph

      On Windows 7 do

   .. container:: ulist

      -  Click on the **Start** Menu

      -  Right click on **Computer**

      -  Select **Properties**

   .. container:: paragraph

      On Windows 8/10 do

   .. container:: ulist

      -  Click on the **Start** Menu

      -  Select **System**

   .. container:: paragraph

      Then do the following

   .. container:: ulist

      -  Select **Advanced System Settings**

      -  On the **Advanced** tab, click the **Environment Variables**
         button

      -  Edit an existing variable, or create a new System variable:
         'Variable name'="APEX_HOME", 'Variable
         value'="C:\apex\apex-full-2.0.0-SNAPSHOT"

   .. container:: paragraph

      For the settings to take effect, an application needs to be
      restarted (e.g. any open ``cmd`` window).

Edit the APEX Logging Settings
##############################

   .. container:: paragraph

      Configure the APEX logging settings to your requirements, for
      instance:

   .. container:: ulist

      -  change the directory where logs are written to, or

      -  change the log levels

   .. container:: paragraph

      Edit the file ``$APEX_HOME/etc/logback.xml`` for any required
      changes. To change the log directory change the line

   .. container:: paragraph

      ``<property name="logDir" value="/var/log/onap/policy/apex-pdp/" />``

   .. container:: paragraph

      to

   .. container:: paragraph

      ``<property name="logDir" value="/PATH/TO/LOG/DIRECTORY/" />``

   .. container:: paragraph

      On Windows, it is recommended to change the log directory to:

   .. container:: paragraph

      ``<property name="logDir" value="C:/apex/apex-full-2.0.0-SNAPSHOT/logs" />``

   .. container:: paragraph

      Note: Be careful about when to use ``\`` vs. ``/`` as the path
      separator!

Create Directories for Logging
##############################

   .. container:: paragraph

      Make sure that the log directory exists. This is important when
      APEX was installed manually or when the log directory was changed
      in the settings (see above).

   +-----------------------------------------------------------------------+-------------------------------------------------------+
   | Unix, Cygwin                                                          | Windows                                               |
   +=======================================================================+=======================================================+
   | .. container::                                                        | .. container::                                        |
   |                                                                       |                                                       |
   |    .. container:: content                                             |    .. container:: content                             |
   |                                                                       |                                                       |
   |       .. code::                                                       |       .. code::                                       |
   |         :number-lines:                                                |         :number-lines:                                |
   |                                                                       |                                                       |
   |         sudo mkdir -p /var/log/onap/policy/apex-pdp                   |         >mkdir C:\apex\apex-full-2.0.0-SNAPSHOT\logs  |
   |         sudo chown -R apexuser:apexuser /var/log/onap/policy/apex-pdp |                                                       |
   +-----------------------------------------------------------------------+-------------------------------------------------------+

Verify the APEX Installation
----------------------------

   .. container:: paragraph

      When APEX is installed and all settings are realized, the
      installation can be verified.

Verify Installation - run Engine
################################

      .. container:: paragraph

         A simple verification of an APEX installation can be done by
         simply starting the APEX engine without specifying a tosca policy. On
         Unix (or Cygwin) start the engine using
         ``$APEX_HOME/bin/apexApps.sh engine``. On Windows start the engine
         using ``%APEX_HOME%\bin\apexApps.bat engine``. The engine will fail
         to fully start. However, if the output looks similar to the
         following line, the APEX installation is realized.

      .. container:: listingblock

         .. container:: content

            .. code::
               :number-lines:

               Starting Apex service with parameters [] . . .
               start of Apex service failed.
               org.onap.policy.apex.model.basicmodel.concepts.ApexException: Arguments validation failed.
                at org.onap.policy.apex.service.engine.main.ApexMain.populateApexParameters(ApexMain.java:238)
                at org.onap.policy.apex.service.engine.main.ApexMain.<init>(ApexMain.java:86)
                at org.onap.policy.apex.service.engine.main.ApexMain.main(ApexMain.java:351)
               Caused by: org.onap.policy.apex.model.basicmodel.concepts.ApexException: Tosca Policy file was not specified as an argument
                at org.onap.policy.apex.service.engine.main.ApexCommandLineArguments.validateReadableFile(ApexCommandLineArguments.java:242)
                at org.onap.policy.apex.service.engine.main.ApexCommandLineArguments.validate(ApexCommandLineArguments.java:172)
                at org.onap.policy.apex.service.engine.main.ApexMain.populateApexParameters(ApexMain.java:235)
                ... 2 common frames omitted

Verify Installation - run an Example
####################################

   .. container:: paragraph

      A full APEX installation comes with several examples. Here, we can
      fully verify the installation by running one of the examples.

   .. container:: paragraph

      We use the example called *SampleDomain* and configure the engine
      to use standard in and standard out for events. Run the engine
      with the provided configuration. Note: Cygwin executes scripts as
      Unix scripts but runs Java as a Windows application, thus the
      configuration file must be given as a Windows path.

   .. container:: paragraph

      On Unix/Linux flavoured platforms, give the commands below:

   .. container:: listingblock

      .. container:: content

        .. code::
         :number-lines:

          sudo su - apexuser
          export APEX_HOME <path to apex installation>
          export APEX_USER apexuser

   .. container:: paragraph

         Create a Tosca Policy for the SampleDomain example using ApexCliToscaEditor
         as explained in the section "The APEX CLI Tosca Editor". Assume the tosca policy name is SampleDomain_tosca.json.
         You can then try to run apex using the ToscaPolicy.

   .. container:: listingblock

      .. container:: content

        .. code::
         :number-lines:

          # $APEX_HOME/bin/apexApps.sh engine -p $APEX_HOME/examples/SampleDomain_tosca.json (1)
          >%APEX_HOME%\bin\apexApps.bat engine -p %APEX_HOME%\examples\SampleDomain_tosca.json(2)

.. container:: colist arabic

   +-------+---------+
   | **1** | UNIX    |
   +-------+---------+
   | **2** | Windows |
   +-------+---------+

.. container:: paragraph

   The engine should start successfully. Assuming the logging levels are set to ``info`` in the built system, the output
   should look similar to this (last few lines)

.. container:: listingblock

   .. container:: content

      .. code::
         :number-lines:

         Starting Apex service with parameters [-p, /home/ubuntu/apex/SampleDomain_tosca.json] . . .
         2018-09-05 15:16:42,800 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Created apex engine MyApexEngine-0:0.0.1 .
         2018-09-05 15:16:42,804 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Created apex engine MyApexEngine-1:0.0.1 .
         2018-09-05 15:16:42,804 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Created apex engine MyApexEngine-2:0.0.1 .
         2018-09-05 15:16:42,805 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Created apex engine MyApexEngine-3:0.0.1 .
         2018-09-05 15:16:42,805 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - APEX service created.
         2018-09-05 15:16:43,962 Apex [main] INFO o.o.p.a.s.e.e.EngDepMessagingService - engine<-->deployment messaging starting . . .
         2018-09-05 15:16:43,963 Apex [main] INFO o.o.p.a.s.e.e.EngDepMessagingService - engine<-->deployment messaging started
         2018-09-05 15:16:44,987 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Registering apex model on engine MyApexEngine-0:0.0.1
         2018-09-05 15:16:45,112 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Registering apex model on engine MyApexEngine-1:0.0.1
         2018-09-05 15:16:45,113 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Registering apex model on engine MyApexEngine-2:0.0.1
         2018-09-05 15:16:45,113 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Registering apex model on engine MyApexEngine-3:0.0.1
         2018-09-05 15:16:45,120 Apex [main] INFO o.o.p.a.s.e.r.impl.EngineServiceImpl - Added the action listener to the engine
         Started Apex service

.. container:: paragraph

   Important are the last two line, stating that APEX has added the
   final action listener to the engine and that the engine is started.

.. container:: paragraph

   The engine is configured to read events from standard input and write
   produced events to standard output. The policy model is a very simple
   policy.

.. container:: paragraph

   The following table shows an input event in the left column and an
   output event in the right column. Past the input event into the
   console where APEX is running, and the output event should appear in
   the console. Pasting the input event multiple times will produce
   output events with different values.

+----------------------------------------------------+----------------------------------------------------+
| Input Event                                        | Example Output Event                               |
+====================================================+====================================================+
| .. container::                                     | .. container::                                     |
|                                                    |                                                    |
| .. container:: content                             | .. container:: content                             |
|                                                    |                                                    |
| .. code::                                          | .. code::                                          |
| :number-lines:                                     | :number-lines:                                     |
|                                                    |                                                    |
| {                                                  | {                                                  |
| "nameSpace": "org.onap.policy.apex.sample.events", | "name": "Event0004",                               |
| "name": "Event0000",                               | "version": "0.0.1",                                |
| "version": "0.0.1",                                | "nameSpace": "org.onap.policy.apex.sample.events", |
| "source": "test",                                  | "source": "Act",                                   |
| "target": "apex",                                  | "target": "Outside",                               |
| "TestSlogan": "Test slogan for External Event0",   | "TestActCaseSelected": 2,                          |
| "TestMatchCase": 0,                                | "TestActStateTime": 1536157104627,                 |
| "TestTimestamp": 1469781869269,                    | "TestDecideCaseSelected": 0,                       |
| "TestTemperature": 9080.866                        | "TestDecideStateTime": 1536157104625,              |
| }                                                  | "TestEstablishCaseSelected": 0,                    |
|                                                    | "TestEstablishStateTime": 1536157104623,           |
|                                                    | "TestMatchCase": 0,                                |
|                                                    | "TestMatchCaseSelected": 1,                        |
|                                                    | "TestMatchStateTime": 1536157104620,               |
|                                                    | "TestSlogan": "Test slogan for External Event0",   |
|                                                    | "TestTemperature": 9080.866,                       |
|                                                    | "TestTimestamp": 1469781869269                     |
|                                                    | }                                                  |
+----------------------------------------------------+----------------------------------------------------+

.. container:: paragraph

   Terminate APEX by simply using ``CTRL+C`` in the console.

Verify a Full Installation - REST Client
########################################

   .. container:: paragraph

      APEX has a REST application for deploying, monitoring, and viewing policy models. The
      application can also be used to create new policy models close to
      the engine native policy language. Start the REST client as
      follows.

   .. container:: listingblock

      .. container:: content

         .. code::
            :number-lines:

            # $APEX_HOME/bin/apexApps.sh full-client

.. container:: listingblock

   .. container:: content

      .. code::
            :number-lines:

            >%APEX_HOME%\bin\apexApps.bat full-client

.. container:: paragraph

   The script will start a simple web server
   (`Grizzly <https://javaee.github.io/grizzly/>`__) and deploy a
   ``war`` web archive in it. Once the client is started, it will be
   available on ``localhost:18989``. The last few line of the messages
   should be:

.. container:: listingblock

   .. container:: content

      .. code::
         :number-lines:

         Apex Editor REST endpoint (ApexServicesRestMain: Config=[ApexServicesRestParameters: URI=http://localhost:18989/apexservices/, TTL=-1sec], State=READY) starting at http://localhost:18989/apexservices/ . . .
         Jul 02, 2020 2:57:39 PM org.glassfish.grizzly.http.server.NetworkListener start
         INFO: Started listener bound to [localhost:18989]
         Jul 02, 2020 2:57:39 PM org.glassfish.grizzly.http.server.HttpServer start
         INFO: [HttpServer] Started.
         Apex Editor REST endpoint (ApexServicesRestMain: Config=[ApexServicesRestParameters: URI=http://localhost:18989/apexservices/, TTL=-1sec], State=RUNNING) started at http://localhost:18989/apexservices/


.. container:: paragraph

   Now open a browser (Firefox, Chrome, Opera, Internet Explorer) and
   use the URL ``http://localhost:18989/``. This will connect the
   browser to the started REST client. Click on the "Policy Editor" button and the Policy Editor start screen should be as
   follows.

.. container:: imageblock

   .. container:: content

      |Policy Editor Start Screen|

   .. container:: title

      Figure 1. Policy Editor Start Screen

.. container:: paragraph

   Now load a policy model by clicking the menu ``File`` and then
   ``Open``. In the opened dialog, go to the directory where APEX is
   installed, then ``examples``, ``models``, ``SampleDomain``, and there
   select the file ``SamplePolicyModelJAVA.json``. This will load the
   policy model used to verify the policy engine (see above). Once
   loaded, the screen should look as follows.

.. container:: imageblock

   .. container:: content

      |Policy Editor with loaded SampleDomain Policy Model|

   .. container:: title

      Figure 2. Policy Editor with loaded SampleDomain Policy Model

.. container:: paragraph

   Now you can use the Policy editor. To finish this verification, simply
   terminate your browser (or the tab), and then use ``CTRL+C`` in the
   console where you started the Policy editor.

Installing the WAR Application
------------------------------

   .. container:: paragraph

      The three APEX clients are packaged in a WAR file. This is a complete
      application that can be installed and run in an application
      server. The application is realized as a servlet. You
      can find the WAR application in the `ONAP Nexus Repository <https://nexus.onap.org/content/groups/public/org/onap/policy/apex-pdp/client/apex-client-full/>`__.


   .. container:: paragraph

      Installing and using the WAR application requires a web server
      that can execute ``war`` web archives. We recommend to use `Apache
      Tomcat <https://tomcat.apache.org/>`__, however other web servers
      can be used as well.

   .. container:: paragraph

      Install Apache Tomcat including the ``Manager App``, see `V9.0
      Docs <https://tomcat.apache.org/tomcat-9.0-doc/manager-howto.html#Configuring_Manager_Application_Access>`__
      for details. Start the Tomcat service, or make sure that Tomcat is
      running.

   .. container:: paragraph

      There are multiple ways to install the APEX WAR application:

   .. container:: ulist

      -  copy the ``.war`` file into the Tomcat ``webapps`` folder

      -  use the Tomcat ``Manager App`` to deploy via the web interface

      -  deploy using a REST call to Tomcat

   .. container:: paragraph

      For details on how to install ``war`` files please consult the
      `Tomcat
      Documentation <https://tomcat.apache.org/tomcat-9.0-doc/index.html>`__
      or the `Manager App
      HOW-TO <https://tomcat.apache.org/tomcat-9.0-doc/manager-howto.html>`__.
      Once you installed an APEX WAR application (and wait for
      sufficient time for Tomcat to finalize the installation), open the
      ``Manager App`` in Tomcat. You should see the APEX WAR application
      being installed and running.

   .. container:: paragraph

      In case of errors, examine the log files in the Tomcat log
      directory. In a conventional install, those log files are in the
      logs directory where Tomcat is installed.

   .. container:: paragraph

      The WAR application file has a name similar to *apex-client-full-<VERSION>.war*.

Running APEX in Docker
----------------------

   .. container:: paragraph

      Since APEX is in ONAP, we provide a full virtualization
      environment for the engine.

Run in ONAP
###########

      .. container:: paragraph

         Running APEX from the ONAP docker repository only requires 2
         commands:

      .. container:: olist arabic

         #. Log into the ONAP docker repo

      .. container:: listingblock

         .. container:: content

::

               docker login -u docker -p docker nexus3.onap.org:10003

      .. container:: olist arabic

         #. Run the APEX docker image

      .. container:: listingblock

         .. container:: content

            ::

               docker run -it --rm  nexus3.onap.org:10003/onap/policy-apex-pdp:latest

Build a Docker Image
####################

      .. container:: paragraph

         Alternatively, one can use the Dockerfile defined in the Docker
         package to build an image.

      .. container:: listingblock

         .. container:: title

            APEX Dockerfile

         .. container:: content

            .. code::
               :number-lines:

               #
               # Docker file to build an image that runs APEX on Java 8 in Ubuntu
               #
               FROM ubuntu:16.04

               RUN apt-get update && \
                       apt-get upgrade -y && \
                       apt-get install -y software-properties-common && \
                       add-apt-repository ppa:openjdk-r/ppa -y && \
                       apt-get update && \
                       apt-get install -y openjdk-8-jdk

               # Create apex user and group
               RUN groupadd apexuser
               RUN useradd --create-home -g apexuser apexuser

               # Add Apex-specific directories and set ownership as the Apex admin user
               RUN mkdir -p /opt/app/policy/apex-pdp
               RUN mkdir -p /var/log/onap/policy/apex-pdp
               RUN chown -R apexuser:apexuser /var/log/onap/policy/apex-pdp

               # Unpack the tarball
               RUN mkdir /packages
               COPY apex-pdp-package-full.tar.gz /packages
               RUN tar xvfz /packages/apex-pdp-package-full.tar.gz --directory /opt/app/policy/apex-pdp
               RUN rm /packages/apex-pdp-package-full.tar.gz

               # Ensure everything has the correct permissions
               RUN find /opt/app -type d -perm 755
               RUN find /opt/app -type f -perm 644
               RUN chmod a+x /opt/app/policy/apex-pdp/bin/*

               # Copy examples to Apex user area
               RUN cp -pr /opt/app/policy/apex-pdp/examples /home/apexuser

               RUN apt-get clean

               RUN chown -R apexuser:apexuser /home/apexuser/*

               USER apexuser
               ENV PATH /opt/app/policy/apex-pdp/bin:$PATH
               WORKDIR /home/apexuser

Running APEX in Standalone mode
-------------------------------

   .. container:: paragraph

      APEX Engine can run in standalone mode by taking in a ToscaPolicy
      as an argument and executing it.
      Assume there is a tosca policy named ToscaPolicy.json in APEX_HOME directory
      This policy can be executed in standalone mode using any of the below methods.

Run in an APEX installation
###########################

   .. container:: listingblock

      .. container:: content

        .. code::
         :number-lines:

          # $APEX_HOME/bin/apexApps.sh engine -p $APEX_HOME/ToscaPolicy.json(1)
          >%APEX_HOME%\bin\apexApps.bat engine -p %APEX_HOME%\ToscaPolicy.json(2)

.. container:: colist arabic

   +-------+---------+
   | **1** | UNIX    |
   +-------+---------+
   | **2** | Windows |
   +-------+---------+

Run in a docker container
#########################

   .. container:: listingblock

      .. container:: content

        .. code::
         :number-lines:

          # docker run -p 6969:6969 -v $APEX_HOME/ToscaPolicy.json:/tmp/policy/ToscaPolicy.json \
            --name apex -it nexus3.onap.org:10001/onap/policy-apex-pdp:latest \
            -c "/opt/app/policy/apex-pdp/bin/apexEngine.sh -p /tmp/policy/ToscaPolicy.json"

APEX Configurations Explained
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Introduction to APEX Configuration
----------------------------------

         .. container:: paragraph

            An APEX engine can be configured to use various combinations
            of event input handlers, event output handlers, event
            protocols, context handlers, and logic executors. The system
            is build using a plugin architecture. Each configuration
            option is realized by a plugin, which can be loaded and
            configured when the engine is started. New plugins can be
            added to the system at any time, though to benefit from a
            new plugin an engine will need to be restarted.

         .. container:: imageblock

            .. container:: content

               |APEX Configuration Matrix|

            .. container:: title

               Figure 3. APEX Configuration Matrix

         .. container:: paragraph

            The APEX distribution already comes with a number of
            plugins. The figure above shows the provided plugins. Any
            combination of input, output, event protocol, context
            handlers, and executors is possible.

General Configuration Format
----------------------------

         .. container:: paragraph

            The APEX configuration file is a JSON file containing a few
            main blocks for different parts of the configuration. Each
            block then holds the configuration details. The following
            code shows the main blocks:

         .. container:: listingblock

            .. container:: content

               .. code::

                  {
                    "engineServiceParameters":{
                      ... (1)
                      "engineParameters":{ (2)
                        "executorParameters":{...}, (3)
                        "contextParameters":{...} (4)
                        "taskParameters":[...] (5)
                      }
                    },
                    "eventInputParameters":{ (6)
                      "input1":{ (7)
                        "carrierTechnologyParameters":{...},
                        "eventProtocolParameters":{...}
                      },
                      "input2":{...}, (8)
                        "carrierTechnologyParameters":{...},
                        "eventProtocolParameters":{...}
                      },
                      ... (9)
                    },
                    "eventOutputParameters":{ (10)
                      "output1":{ (11)
                        "carrierTechnologyParameters":{...},
                        "eventProtocolParameters":{...}
                      },
                      "output2":{ (12)
                        "carrierTechnologyParameters":{...},
                        "eventProtocolParameters":{...}
                      },
                      ... (13)
                    }
                  }

         .. container:: colist arabic

            +-----------------------------------+-----------------------------------+
            | **1**                             | main engine configuration         |
            +-----------------------------------+-----------------------------------+
            | **2**                             | engine parameters for plugin      |
            |                                   | configurations (execution         |
            |                                   | environments and context          |
            |                                   | handling)                         |
            +-----------------------------------+-----------------------------------+
            | **3**                             | engine specific parameters,       |
            |                                   | mainly for executor plugins       |
            +-----------------------------------+-----------------------------------+
            | **4**                             | context specific parameters, e.g. |
            |                                   | for context schemas, persistence, |
            |                                   | etc.                              |
            +-----------------------------------+-----------------------------------+
            | **5**                             | list of task parameters that      |
            |                                   | should be made available in task  |
            |                                   | logic (optional).                 |
            +-----------------------------------+-----------------------------------+
            | **6**                             | configuration of the input        |
            |                                   | interface                         |
            +-----------------------------------+-----------------------------------+
            | **7**                             | an example input called           |
            |                                   | ``input1`` with carrier           |
            |                                   | technology and event protocol     |
            +-----------------------------------+-----------------------------------+
            | **8**                             | an example input called           |
            |                                   | ``input2`` with carrier           |
            |                                   | technology and event protocol     |
            +-----------------------------------+-----------------------------------+
            | **9**                             | any further input configuration   |
            +-----------------------------------+-----------------------------------+
            | **10**                            | configuration of the output       |
            |                                   | interface                         |
            +-----------------------------------+-----------------------------------+
            | **11**                            | an example output called          |
            |                                   | ``output1`` with carrier          |
            |                                   | technology and event protocol     |
            +-----------------------------------+-----------------------------------+
            | **12**                            | an example output called          |
            |                                   | ``output2`` with carrier          |
            |                                   | technology and event protocol     |
            +-----------------------------------+-----------------------------------+
            | **13**                            | any further output configuration  |
            +-----------------------------------+-----------------------------------+

Engine Service Parameters
-------------------------

         .. container:: paragraph

            The configuration provides a number of parameters to
            configure the engine. An example configuration with
            explanations of all options is shown below.

         .. container:: listingblock

            .. container:: content

               .. code::

                  "engineServiceParameters" : {
                    "name"          : "AADMApexEngine", (1)
                    "version"        : "0.0.1",  (2)
                    "id"             :  45,  (3)
                    "instanceCount"  : 4,  (4)
                    "deploymentPort" : 12345,  (5)
                    "policy_type_impl" : {...}, (6)
                    "periodicEventPeriod": 1000, (7)
                    "engineParameters":{ (8)
                      "executorParameters":{...}, (9)
                      "contextParameters":{...}, (10)
                      "taskParameters":[...] (11)
                    }
                  }

         .. container:: colist arabic

            +-----------------------------------+-----------------------------------+
            | **1**                             | a name for the engine. The engine |
            |                                   | name is used to create a key in a |
            |                                   | runtime engine. An name matching  |
            |                                   | the following regular expression  |
            |                                   | can be used here:                 |
            |                                   | ``[A-Za-z0-9\\-_\\.]+``           |
            +-----------------------------------+-----------------------------------+
            | **2**                             | a version of the engine, use      |
            |                                   | semantic versioning as explained  |
            |                                   | here: `Semantic                   |
            |                                   | Versioning <http://semver.org/>`_ |
            |                                   | _.                                |
            |                                   | This version is used in a runtime |
            |                                   | engine to create a version of the |
            |                                   | engine. For that reason, the      |
            |                                   | version must match the following  |
            |                                   | regular expression ``[A-Z0-9.]+`` |
            +-----------------------------------+-----------------------------------+
            | **3**                             | a numeric identifier for the      |
            |                                   | engine                            |
            +-----------------------------------+-----------------------------------+
            | **4**                             | the number of threads (policy     |
            |                                   | instances executed in parallel)   |
            |                                   | the engine should use, use ``1``  |
            |                                   | for single threaded engines       |
            +-----------------------------------+-----------------------------------+
            | **5**                             | the port for the deployment       |
            |                                   | Websocket connection to the       |
            |                                   | engine                            |
            +-----------------------------------+-----------------------------------+
            | **6**                             | the APEX policy model as a JSON   |
            |                                   | or YAML block to load into the    |
            |                                   | engine on startup when            |
            |                                   | APEX is running a policy that has |
            |                                   | its logic and parameters          |
            |                                   | specified in TOSCA                |
            |                                   | (optional)                        |
            +-----------------------------------+-----------------------------------+
            | **7**                             | an optional timer for periodic    |
            |                                   | policies, in milliseconds (a      |
            |                                   | defined periodic policy will be   |
            |                                   | executed every ``X``              |
            |                                   | milliseconds), not used of not    |
            |                                   | set or ``0``                      |
            +-----------------------------------+-----------------------------------+
            | **8**                             | engine parameters for plugin      |
            |                                   | configurations (execution         |
            |                                   | environments and context          |
            |                                   | handling)                         |
            +-----------------------------------+-----------------------------------+
            | **9**                             | engine specific parameters,       |
            |                                   | mainly for executor plugins       |
            +-----------------------------------+-----------------------------------+
            | **10**                            | context specific parameters, e.g. |
            |                                   | for context schemas, persistence, |
            |                                   | etc.                              |
            +-----------------------------------+-----------------------------------+
            | **11**                            | list of task parameters that      |
            |                                   | should be made available in task  |
            |                                   | logic (optional).                 |
            +-----------------------------------+-----------------------------------+

         .. container:: paragraph

            The model file is optional, it can also be specified via
            command line. In any case, make sure all execution and other
            required plug-ins for the loaded model are loaded as
            required.

Input and Output Interfaces
---------------------------

         .. container:: paragraph

            An APEX engine has two main interfaces:

         .. container:: ulist

            -  An *input* interface to receive events: also known as
               ingress interface or consumer, receiving (consuming)
               events commonly named triggers, and

            -  An *output* interface to publish produced events: also
               known as egress interface or producer, sending
               (publishing) events commonly named actions or action
               events.

         .. container:: paragraph

            The input and output interface is configured in terms of
            inputs and outputs, respectively. Each input and output is a
            combination of a carrier technology and an event protocol.
            Carrier technologies and event protocols are provided by
            plugins, each with its own specific configuration. Most
            carrier technologies can be configured for input as well as
            output. Most event protocols can be used for all carrier
            technologies. One exception is the JMS object event
            protocol, which can only be used for the JMS carrier
            technology. Some further restrictions apply (for instance
            for carrier technologies using bi- or uni-directional
            modes).

         .. container:: paragraph

            Input and output interface can be configured separately, in
            isolation, with any number of carrier technologies. The
            resulting general configuration options are:

         .. container:: ulist

            -  Input interface with one or more inputs

               .. container:: ulist

                  -  each input with a carrier technology and an event
                     protocol

                  -  some inputs with optional synchronous mode

                  -  some event protocols with additional parameters

            -  Output interface with one or more outputs

               .. container:: ulist

                  -  each output with a carrier technology and an event
                     encoding

                  -  some outputs with optional synchronous mode

                  -  some event protocols with additional parameters

         .. container:: paragraph

            The configuration for input and output is contained in
            ``eventInputParameters`` and ``eventOutputParameters``,
            respectively. Inside here, one can configure any number of
            inputs and outputs. Each of them needs to have a unique
            identifier (name), the content of the name is free form. The
            example below shows a configuration for two inputs and two
            outputs.

         .. container:: listingblock

            .. container:: content

               .. code::

                  "eventInputParameters": { (1)
                    "FirstConsumer": { (2)
                      "carrierTechnologyParameters" : {...}, (3)
                      "eventProtocolParameters":{...}, (4)
                      ... (5)
                    },
                    "SecondConsumer": { (6)
                      "carrierTechnologyParameters" : {...}, (7)
                      "eventProtocolParameters":{...}, (8)
                      ... (9)
                    },
                  },
                  "eventOutputParameters": { (10)
                    "FirstProducer": { (11)
                      "carrierTechnologyParameters":{...}, (12)
                      "eventProtocolParameters":{...}, (13)
                      ... (14)
                    },
                    "SecondProducer": { (15)
                      "carrierTechnologyParameters":{...}, (16)
                      "eventProtocolParameters":{...}, (17)
                      ... (18)
                    }
                  }

         .. container:: colist arabic

            +--------+--------------------------------------------------------------------+
            | **1**  | input interface configuration, APEX input plugins                  |
            +--------+--------------------------------------------------------------------+
            | **2**  | first input called ``FirstConsumer``                               |
            +--------+--------------------------------------------------------------------+
            | **3**  | carrier technology for plugin                                      |
            +--------+--------------------------------------------------------------------+
            | **4**  | event protocol for plugin                                          |
            +--------+--------------------------------------------------------------------+
            | **5**  | any other input configuration (e.g. event name filter, see below)  |
            +--------+--------------------------------------------------------------------+
            | **6**  | second input called ``SecondConsumer``                             |
            +--------+--------------------------------------------------------------------+
            | **7**  | carrier technology for plugin                                      |
            +--------+--------------------------------------------------------------------+
            | **8**  | event protocol for plugin                                          |
            +--------+--------------------------------------------------------------------+
            | **9**  | any other plugin configuration                                     |
            +--------+--------------------------------------------------------------------+
            | **10** | output interface configuration, APEX output plugins                |
            +--------+--------------------------------------------------------------------+
            | **11** | first output called ``FirstProducer``                              |
            +--------+--------------------------------------------------------------------+
            | **12** | carrier technology for plugin                                      |
            +--------+--------------------------------------------------------------------+
            | **13** | event protocol for plugin                                          |
            +--------+--------------------------------------------------------------------+
            | **14** | any other plugin configuration                                     |
            +--------+--------------------------------------------------------------------+
            | **15** | second output called ``SecondProducer``                            |
            +--------+--------------------------------------------------------------------+
            | **16** | carrier technology for plugin                                      |
            +--------+--------------------------------------------------------------------+
            | **17** | event protocol for plugin                                          |
            +--------+--------------------------------------------------------------------+
            | **18** | any other output configuration (e.g. event name filter, see below) |
            +--------+--------------------------------------------------------------------+

Event Name
##########

            .. container:: paragraph

               Any event defined in APEX has to be unique. The "name" of
               of an event is used as an identifier for an ApexEvent. Every
               event has to be tagged to an eventName. This can be done in different
               ways. Either the actual event can have a field called "name". Or, the
               event has some other field that can act as the identifier, which can be
               specified using "nameAlias". But in other cases, where a "name" or "nameAlias"
               cannot be specified, the incoming event coming over an endpoint can be
               manually tagged to an "eventName" before consuming it.

            .. container:: paragraph

               The "eventName" can have a single event's name if the event coming
               over the endpoint has to be always mapped to the specified eventName's
               definition. Otherwise, if different events can come over the endpoint,
               then "eventName" field can consist of multiple event names separated by
               "|" symbol. In this case, based on the received event's structure, it is
               mapped to any one of the event name specified in the "eventName" field.

            .. container:: paragraph

               The following code shows some examples on how to specify the eventName field:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventInputParameters": {
                       "Input1": {
                         "carrierTechnologyParameters" : {...},
                         "eventProtocolParameters":{...},
                         "eventName" : "VesEvent" (1)
                       },
                       "Input2": {
                         "carrierTechnologyParameters" : {...},
                         "eventProtocolParameters":{...},
                         "eventName" : "AAISuccessResponseEvent|AAIFailureResponseEvent" (2)
                       }
                     }

Event Filters
#############

            .. container:: paragraph

               APEX will always send an event after a policy execution
               is finished. For a successful execution, the event sent
               is the output event created by the policy. In case the
               policy does not create an output event, APEX will create
               a new event with all input event fields plus an
               additional field ``exceptionMessage`` with an exception
               message.

            .. container:: paragraph

               There are situations in which this auto-generated error
               event might not be required or wanted:

            .. container:: ulist

               -  when a policy failing should not result in an event
                  send out via an output interface

               -  when the auto-generated event goes back in an APEX
                  engine (or the same APEX engine), this can create
                  endless loops

               -  the auto-generated event should go to a special output
                  interface or channel

            .. container:: paragraph

               All of these situations are supported by a filter option
               using a wildecard (regular expression) configuration on
               APEX I/O interfaces. The parameter is called
               ``eventNameFilter`` and the value are `Java regular
               expressions <https://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html>`__
               (a
               `tutorial <http://www.vogella.com/tutorials/JavaRegularExpressions/article.html>`__).
               The following code shows some examples:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventInputParameters": {
                       "Input1": {
                         "carrierTechnologyParameters" : {...},
                         "eventProtocolParameters":{...},
                         "eventNameFilter" : "^E[Vv][Ee][Nn][Tt][0-9]004$" (1)
                       }
                     },
                     "eventOutputParameters": {
                       "Output1": {
                         "carrierTechnologyParameters":{...},
                         "eventProtocolParameters":{...},
                         "eventNameFilter" : "^E[Vv][Ee][Nn][Tt][0-9]104$" (2)
                       }
                     }

Executors
---------

         .. container:: paragraph

            Executors are plugins that realize the execution of logic
            contained in a policy model. Logic can be in a task
            selector, a task, and a state finalizer. Using plugins for
            execution environments makes APEX very flexible to support
            virtually any executable logic expressions.

         .. container:: paragraph

            APEX 2.0.0-SNAPSHOT supports the following executors:

         .. container:: ulist

            -  Java, for Java implemented logic

               .. container:: ulist

                  -  This executor requires logic implemented using the
                     APEX Java interfaces.

                  -  Generated JAR files must be in the classpath of the
                     APEX engine at start time.

            -  Javascript

            -  JRuby,

            -  Jython,

            -  MVEL

               .. container:: ulist

                  -  This executor uses the latest version of the MVEL
                     engine, which can be very hard to debug and can
                     produce unwanted side effects during execution

Configure the Javascript Executor
#################################

            .. container:: paragraph

               The Javascript executor is added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters":{
                       "engineParameters":{
                         "executorParameters":{
                           "JAVASCRIPT":{
                             "parameterClassName" :
                             "org.onap.policy.apex.plugins.executor.javascript.JavascriptExecutorParameters"
                           }
                         }
                       }
                     }

Configure the Jython Executor
#############################

            .. container:: paragraph

               The Jython executor is added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters":{
                       "engineParameters":{
                         "executorParameters":{
                           "JYTHON":{
                             "parameterClassName" :
                             "org.onap.policy.apex.plugins.executor.jython.JythonExecutorParameters"
                           }
                         }
                       }
                     }

Configure the JRuby Executor
############################

            .. container:: paragraph

               The JRuby executor is added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters":{
                       "engineParameters":{
                         "executorParameters":{
                           "JRUBY":{
                             "parameterClassName" :
                             "org.onap.policy.apex.plugins.executor.jruby.JrubyExecutorParameters"
                           }
                         }
                       }
                     }

Configure the Java Executor
###########################

            .. container:: paragraph

               The Java executor is added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters":{
                       "engineParameters":{
                         "executorParameters":{
                           "JAVA":{
                             "parameterClassName" :
                             "org.onap.policy.apex.plugins.executor.java.JavaExecutorParameters"
                           }
                         }
                       }
                     }

Configure the MVEL Executor
###########################

            .. container:: paragraph

               The MVEL executor is added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters":{
                       "engineParameters":{
                         "executorParameters":{
                           "MVEL":{
                             "parameterClassName" :
                             "org.onap.policy.apex.plugins.executor.mvel.MVELExecutorParameters"
                           }
                         }
                       }
                     }

Context Handlers
----------------

         .. container:: paragraph

            Context handlers are responsible for all context processing.
            There are the following main areas:

         .. container:: ulist

            -  Context schema: use schema handlers other than Java class
               (supported by default without configuration)

            -  Context distribution: distribute context across multiple
               APEX engines

            -  Context locking: mechanisms to lock context elements for
               read/write

            -  Context persistence: mechanisms to persist context

         .. container:: paragraph

            APEX provides plugins for each of the main areas.

Configure AVRO Schema Handler
#############################

            .. container:: paragraph

               The AVRO schema handler is added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters":{
                       "engineParameters":{
                         "contextParameters":{
                           "parameterClassName" : "org.onap.policy.apex.context.parameters.ContextParameters",
                           "schemaParameters":{
                             "Avro":{
                               "parameterClassName" :
                                 "org.onap.policy.apex.plugins.context.schema.avro.AvroSchemaHelperParameters"
                             }
                           }
                         }
                       }
                     }

            .. container:: paragraph

               Using the AVRO schema handler has one limitation: AVRO
               only supports field names that represent valid Java class
               names. This means only letters and the character ``_``
               are supported. Characters commonly used in field names,
               such as ``.`` and ``-``, are not supported by AVRO. for
               more information see `Avro Spec:
               Names <https://avro.apache.org/docs/1.8.1/spec.html#names>`__.

            .. container:: paragraph

               To work with this limitation, the APEX Avro plugin will
               parse a given AVRO definition and replace *all*
               occurrences of ``.`` and ``-`` with a ``_``. This means
               that

            .. container:: ulist

               -  In a policy model, if the AVRO schema defined a field
                  as ``my-name`` the policy logic should access it as
                  ``my_name``

               -  In a policy model, if the AVRO schema defined a field
                  as ``my.name`` the policy logic should access it as
                  ``my_name``

               -  There should be no field names that convert to the
                  same internal name

                  .. container:: ulist

                     -  For instance the simultaneous use of
                        ``my_name``, ``my.name``, and ``my-name`` should
                        be avoided

                     -  If not avoided, the event processing might
                        create unwanted side effects

               -  If field names use any other not-supported character,
                  the AVRO plugin will reject it

                  .. container:: ulist

                     -  Since AVRO uses lazy initialization, this
                        rejection might only become visible at runtime

Configure Task Parameters
#########################

            .. container:: paragraph

               The Task Parameters are added to the configuration as
               follows:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "engineServiceParameters": {
                       "engineParameters": {
                         "taskParameters": [
                           {
                             "key": "ParameterKey1",
                             "value": "ParameterValue1"
                           },
                           {
                             "taskId": "Task_Act0",
                             "key": "ParameterKey2",
                             "value": "ParameterValue2"
                           }
                         ]
                       }
                     }

            .. container:: paragraph

               TaskParameters can be used to pass parameters from ApexConfig
               to the policy logic. In the config, these are optional.
               The list of task parameters provided in the config may be added
               to the tasks or existing task parameters in the task will be overriden.

            .. container:: paragraph

               If taskId is provided in ApexConfig for an entry, then that
               parameter is updated only for that particular task. Otherwise,
               the task parameter is added to all tasks.

Carrier Technologies
--------------------

         .. container:: paragraph

            Carrier technologies define how APEX receives (input) and
            sends (output) events. They can be used in any combination,
            using asynchronous or synchronous mode. There can also be
            any number of carrier technologies for the input (consume)
            and the output (produce) interface.

         .. container:: paragraph

            Supported *input* technologies are:

         .. container:: ulist

            -  Standard input, read events from the standard input
               (console), not suitable for APEX background servers

            -  File input, read events from a file

            -  Kafka, read events from a Kafka system

            -  Websockets, read events from a Websocket

            -  JMS,

            -  REST (synchronous and asynchronous), additionally as
               client or server

            -  Event Requestor, allows reading of events that have been
               looped back into APEX

         .. container:: paragraph

            Supported *output* technologies are:

         .. container:: ulist

            -  Standard output, write events to the standard output
               (console), not suitable for APEX background servers

            -  File output, write events to a file

            -  Kafka, write events to a Kafka system

            -  Websockets, write events to a Websocket

            -  JMS

            -  REST (synchronous and asynchronous), additionally as
               client or server

            -  Event Requestor, allows events to be looped back into
               APEX

         .. container:: paragraph

            New carrier technologies can be added as plugins to APEX or
            developed outside APEX and added to an APEX deployment.

Standard IO
###########

            .. container:: paragraph

               Standard IO does not require a specific plugin, it is
               supported be default.

Standard Input
==============
               .. container:: paragraph

                  APEX will take events from its standard input. This
                  carrier is good for testing, but certainly not for a
                  use case where APEX runs as a server. The
                  configuration is as follows:

               .. container:: listingblock

                  .. container:: content

::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "FILE", (1)
                          "parameters" : {
                            "standardIO" : true (2)
                          }
                        }

               .. container:: colist arabic

                  +-------+---------------------------------------+
                  | **1** | standard input is considered a file   |
                  +-------+---------------------------------------+
                  | **2** | file descriptor set to standard input |
                  +-------+---------------------------------------+

Standard Output
===============

               .. container:: paragraph

                  APEX will send events to its standard output. This
                  carrier is good for testing, but certainly not for a
                  use case where APEX runs as a server. The
                  configuration is as follows:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "FILE", (1)
                          "parameters" : {
                            "standardIO" : true  (2)
                          }
                        }

               .. container:: colist arabic

                  +-------+----------------------------------------+
                  | **1** | standard output is considered a file   |
                  +-------+----------------------------------------+
                  | **2** | file descriptor set to standard output |
                  +-------+----------------------------------------+

2.7.2. File IO
##############

            .. container:: paragraph

               File IO does not require a specific plugin, it is
               supported be default.

File Input
==========

               .. container:: paragraph

                  APEX will take events from a file. The same file
                  should not be used as an output. The configuration is
                  as follows:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "FILE", (1)
                          "parameters" : {
                            "fileName" : "examples/events/SampleDomain/EventsIn.xmlfile" (2)
                          }
                        }

               .. container:: colist arabic

                  +-------+------------------------------------------+
                  | **1** | set file input                           |
                  +-------+------------------------------------------+
                  | **2** | the name of the file to read events from |
                  +-------+------------------------------------------+

File Output
===========
               .. container:: paragraph

                  APEX will write events to a file. The same file should
                  not be used as an input. The configuration is as
                  follows:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "FILE", (1)
                          "parameters" : {
                            "fileName"  : "examples/events/SampleDomain/EventsOut.xmlfile" (2)
                          }
                        }

               .. container:: colist arabic

                  +-------+-----------------------------------------+
                  | **1** | set file output                         |
                  +-------+-----------------------------------------+
                  | **2** | the name of the file to write events to |
                  +-------+-----------------------------------------+

Event Requestor IO
##################

            .. container:: paragraph

               Event Requestor IO does not require a specific plugin, it
               is supported be default. It should only be used with the
               APEX event protocol.

Event Requestor Input
=====================

               .. container:: paragraph

                  APEX will take events from APEX.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology": "EVENT_REQUESTOR" (1)
                        }

               .. container:: colist arabic

                  +-------+---------------------------+
                  | **1** | set event requestor input |
                  +-------+---------------------------+

Event Requestor Output
======================

               .. container:: paragraph

                  APEX will write events to APEX.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology": "EVENT_REQUESTOR" (1)
                        }

Peering Event Requestors
========================

               .. container:: paragraph

                  When using event requestors, they need to be peered.
                  This means an event requestor output needs to be
                  peered (associated) with an event requestor input. The
                  following example shows the use of an event requestor
                  with the APEX event protocol and the peering of output
                  and input.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventInputParameters": {
                          "EventRequestorConsumer": {
                            "carrierTechnologyParameters": {
                              "carrierTechnology": "EVENT_REQUESTOR" (1)
                            },
                            "eventProtocolParameters": {
                              "eventProtocol": "APEX" (2)
                            },
                            "eventNameFilter": "InputEvent", (3)
                            "requestorMode": true, (4)
                            "requestorPeer": "EventRequestorProducer", (5)
                            "requestorTimeout": 500 (6)
                          }
                        },
                        "eventOutputParameters": {
                          "EventRequestorProducer": {
                            "carrierTechnologyParameters": {
                              "carrierTechnology": "EVENT_REQUESTOR" (7)
                            },
                            "eventProtocolParameters": {
                              "eventProtocol": "APEX" (8)
                            },
                            "eventNameFilter": "EventListEvent", (9)
                            "requestorMode": true, (10)
                            "requestorPeer": "EventRequestorConsumer", (11)
                            "requestorTimeout": 500 (12)
                          }
                        }

               .. container:: colist arabic

                  +-----------------------------------+-----------------------------------+
                  | **1**                             | event requestor on a consumer     |
                  +-----------------------------------+-----------------------------------+
                  | **2**                             | with APEX event protocol          |
                  +-----------------------------------+-----------------------------------+
                  | **3**                             | optional filter (best to use a    |
                  |                                   | filter to prevent unwanted events |
                  |                                   | on the consumer side)             |
                  +-----------------------------------+-----------------------------------+
                  | **4**                             | activate requestor mode           |
                  +-----------------------------------+-----------------------------------+
                  | **5**                             | the peer to the output (must      |
                  |                                   | match the output carrier)         |
                  +-----------------------------------+-----------------------------------+
                  | **6**                             | an optional timeout in            |
                  |                                   | milliseconds                      |
                  +-----------------------------------+-----------------------------------+
                  | **7**                             | event requestor on a producer     |
                  +-----------------------------------+-----------------------------------+
                  | **8**                             | with APEX event protocol          |
                  +-----------------------------------+-----------------------------------+
                  | **9**                             | optional filter (best to use a    |
                  |                                   | filter to prevent unwanted events |
                  |                                   | on the consumer side)             |
                  +-----------------------------------+-----------------------------------+
                  | **10**                            | activate requestor mode           |
                  +-----------------------------------+-----------------------------------+
                  | **11**                            | the peer to the output (must      |
                  |                                   | match the input carrier)          |
                  +-----------------------------------+-----------------------------------+
                  | **12**                            | an optional timeout in            |
                  |                                   | milliseconds                      |
                  +-----------------------------------+-----------------------------------+

Kafka IO
########

            .. container:: paragraph

               Kafka IO is supported by the APEX Kafka plugin. The
               configurations below are examples. APEX will take any
               configuration inside the parameter object and forward it
               to Kafka. More information on Kafka specific
               configuration parameters can be found in the Kafka
               documentation:

            .. container:: ulist

               -  `Kafka Consumer
                  Class <https://kafka.apache.org/090/javadoc/org/apache/kafka/clients/consumer/KafkaConsumer.html>`__

               -  `Kafka Producer
                  Class <https://kafka.apache.org/090/javadoc/org/apache/kafka/clients/producer/KafkaProducer.html>`__

Kafka Input
===========
               .. container:: paragraph

                  APEX will receive events from the Apache Kafka
                  messaging system. The input is uni-directional, an
                  engine will only receive events from the input but not
                  send any event to the input.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "KAFKA", (1)
                          "parameterClassName" :
                            "org.onap.policy.apex.plugins.event.carrier.kafka.KAFKACarrierTechnologyParameters",
                          "parameters" : {
                            "bootstrapServers"  : "localhost:49092", (2)
                            "groupId"           : "apex-group-id", (3)
                            "enableAutoCommit"  : true, (4)
                            "autoCommitTime"    : 1000, (5)
                            "sessionTimeout"    : 30000, (6)
                            "consumerPollTime"  : 100, (7)
                            "consumerTopicList" : ["apex-in-0", "apex-in-1"], (8)
                            "keyDeserializer"   :
                                "org.apache.kafka.common.serialization.StringDeserializer", (9)
                            "valueDeserializer" :
                                "org.apache.kafka.common.serialization.StringDeserializer" (10)
                            "kafkaProperties": [  (11)
                                                 [
                                                   "security.protocol",
                                                   "SASL_SSL"
                                                 ],
                                                 [
                                                   "ssl.truststore.type",
                                                   "JKS"
                                                 ],
                                                 [
                                                   "ssl.truststore.location",
                                                   "/opt/app/policy/apex-pdp/etc/ssl/test.jks"
                                                 ],
                                                 [
                                                   "ssl.truststore.password",
                                                   "policy0nap"
                                                 ],
                                                 [
                                                   "sasl.mechanism",
                                                   "SCRAM-SHA-512"
                                                 ],
                                                 [
                                                   "sasl.jaas.config",
                                                   "org.apache.kafka.common.security.scram.ScramLoginModule required username=\"policy\" password=\"policy\";"
                                                 ],
                                                 [
                                                   "ssl.endpoint.identification.algorithm",
                                                   ""
                                                 ]
                                               ]
                          }
                        }

               .. container:: colist arabic

                  +--------+-------------------------------------+
                  | **1**  | set Kafka as carrier technology     |
                  +--------+-------------------------------------+
                  | **2**  | bootstrap server and port           |
                  +--------+-------------------------------------+
                  | **3**  | a group identifier                  |
                  +--------+-------------------------------------+
                  | **4**  | flag for auto-commit                |
                  +--------+-------------------------------------+
                  | **5**  | auto-commit timeout in milliseconds |
                  +--------+-------------------------------------+
                  | **6**  | session timeout in milliseconds     |
                  +--------+-------------------------------------+
                  | **7**  | consumer poll time in milliseconds  |
                  +--------+-------------------------------------+
                  | **8**  | consumer topic list                 |
                  +--------+-------------------------------------+
                  | **9**  | key for the Kafka de-serializer     |
                  +--------+-------------------------------------+
                  | **10** | value for the Kafka de-serializer   |
                  +--------+-------------------------------------+
                  | **11** | properties for Kafka connectivity   |
                  +--------+-------------------------------------+

               .. container:: paragraph

                  Kindly note that the above Kafka properties is just a reference,
                  and the actual properties required depends on the Kafka server installation.

                  In cases where the message produced in Kafka topic has been serialized using KafkaAvroSerializer,
                  then the following parameters needs to be additionally added to `KafkaProperties` for the consumer
                  to have the capability of deserializing the message properly while consuming.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        [
                          "value.deserializer",
                          "io.confluent.kafka.serializers.KafkaAvroDeserializer"
                        ],
                        [
                          "schema.registry.url",
                          "<url of the schema registry configured in Kafka cluster for registering Avro schemas>"
                        ]

               .. container:: paragraph

                  For more details on how to setup schema registry for Kafka cluster,
                  kindly take a look `here <https://github.com/confluentinc/schema-registry/blob/master/README.md>`__.


Kafka Output
============
               .. container:: paragraph

                  APEX will send events to the Apache Kafka messaging
                  system. The output is uni-directional, an engine will
                  send events to the output but not receive any event
                  from the output.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "KAFKA", (1)
                          "parameterClassName" :
                            "org.onap.policy.apex.plugins.event.carrier.kafka.KAFKACarrierTechnologyParameters",
                          "parameters" : {
                            "bootstrapServers"  : "localhost:49092", (2)
                            "acks"              : "all", (3)
                            "retries"           : 0, (4)
                            "batchSize"         : 16384, (5)
                            "lingerTime"        : 1, (6)
                            "bufferMemory"      : 33554432, (7)
                            "producerTopic"     : "apex-out", (8)
                            "keySerializer"     :
                                "org.apache.kafka.common.serialization.StringSerializer", (9)
                            "valueSerializer"   :
                                "org.apache.kafka.common.serialization.StringSerializer" (10)
                            "kafkaProperties": [  (11)
                                                 [
                                                   "security.protocol",
                                                   "SASL_SSL"
                                                 ],
                                                 [
                                                   "ssl.truststore.type",
                                                   "JKS"
                                                 ],
                                                 [
                                                   "ssl.truststore.location",
                                                   "/opt/app/policy/apex-pdp/etc/ssl/test.jks"
                                                 ],
                                                 [
                                                   "ssl.truststore.password",
                                                   "policy0nap"
                                                 ],
                                                 [
                                                   "sasl.mechanism",
                                                   "SCRAM-SHA-512"
                                                 ],
                                                 [
                                                   "sasl.jaas.config",
                                                   "org.apache.kafka.common.security.scram.ScramLoginModule required username=\"policy\" password=\"policy\";"
                                                 ],
                                                 [
                                                   "ssl.endpoint.identification.algorithm",
                                                   ""
                                                 ]
                                               ]
                          }
                        }

               .. container:: colist arabic

                  +--------+-----------------------------------+
                  | **1**  | set Kafka as carrier technology   |
                  +--------+-----------------------------------+
                  | **2**  | bootstrap server and port         |
                  +--------+-----------------------------------+
                  | **3**  | acknowledgement strategy          |
                  +--------+-----------------------------------+
                  | **4**  | number of retries                 |
                  +--------+-----------------------------------+
                  | **5**  | batch size                        |
                  +--------+-----------------------------------+
                  | **6**  | time to linger in milliseconds    |
                  +--------+-----------------------------------+
                  | **7**  | buffer memory in byte             |
                  +--------+-----------------------------------+
                  | **8**  | producer topic                    |
                  +--------+-----------------------------------+
                  | **9**  | key for the Kafka serializer      |
                  +--------+-----------------------------------+
                  | **10** | value for the Kafka serializer    |
                  +--------+-----------------------------------+
                  | **11** | properties for Kafka connectivity |
                  +--------+-----------------------------------+
            
               .. container:: paragraph

                  Kindly note that the above Kafka properties is just a reference,
                  and the actual properties required depends on the Kafka server installation.

JMS IO
######

            .. container:: paragraph

               APEX supports the Java Messaging Service (JMS) as input
               as well as output. JMS IO is supported by the APEX JMS
               plugin. Input and output support an event encoding as
               text (JSON string) or object (serialized object). The
               input configuration is the same for both encodings, the
               output configuration differs.

JMS Input
=========
               .. container:: paragraph

                  APEX will receive events from a JMS messaging system.
                  The input is uni-directional, an engine will only
                  receive events from the input but not send any event
                  to the input.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "JMS", (1)
                          "parameterClassName" :
                              "org.onap.policy.apex.plugins.event.carrier.jms.JMSCarrierTechnologyParameters",
                          "parameters" : { (2)
                            "initialContextFactory" :
                                "org.jboss.naming.remote.client.InitialContextFactory", (3)
                            "connectionFactory" : "ConnectionFactory", (4)
                            "providerURL" : "remote://localhost:5445", (5)
                            "securityPrincipal" : "guest", (6)
                            "securityCredentials" : "IAmAGuest", (7)
                            "consumerTopic" : "jms/topic/apexIn" (8)
                          }
                        }

               .. container:: colist arabic

                  +-----------------------------------+-----------------------------------+
                  | **1**                             | set JMS as carrier technology     |
                  +-----------------------------------+-----------------------------------+
                  | **2**                             | set all JMS specific parameters   |
                  +-----------------------------------+-----------------------------------+
                  | **3**                             | the context factory, in this case |
                  |                                   | from JBOSS (it requires the       |
                  |                                   | dependency                        |
                  |                                   | org.jboss:jboss-remote-naming:2.0 |
                  |                                   | .4.Final                          |
                  |                                   | or a different version to be in   |
                  |                                   | the directory ``$APEX_HOME/lib``  |
                  |                                   | or ``%APEX_HOME%\lib``            |
                  +-----------------------------------+-----------------------------------+
                  | **4**                             | a connection factory for the JMS  |
                  |                                   | connection                        |
                  +-----------------------------------+-----------------------------------+
                  | **5**                             | URL with host and port of the JMS |
                  |                                   | provider                          |
                  +-----------------------------------+-----------------------------------+
                  | **6**                             | access credentials, user name     |
                  +-----------------------------------+-----------------------------------+
                  | **7**                             | access credentials, user password |
                  +-----------------------------------+-----------------------------------+
                  | **8**                             | the JMS topic to listen to        |
                  +-----------------------------------+-----------------------------------+

JMS Output with Text
====================

               .. container:: paragraph

                  APEX engine send events to a JMS messaging system. The
                  output is uni-directional, an engine will send events
                  to the output but not receive any event from output.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "JMS", (1)
                          "parameterClassName" :
                              "org.onap.policy.apex.plugins.event.carrier.jms.JMSCarrierTechnologyParameters",
                          "parameters" : { (2)
                            "initialContextFactory" :
                                "org.jboss.naming.remote.client.InitialContextFactory", (3)
                            "connectionFactory" : "ConnectionFactory", (4)
                            "providerURL" : "remote://localhost:5445", (5)
                            "securityPrincipal" : "guest", (6)
                            "securityCredentials" : "IAmAGuest", (7)
                            "producerTopic" : "jms/topic/apexOut", (8)
                            "objectMessageSending": "false" (9)
                          }
                        }

               .. container:: colist arabic

                  +-----------------------------------+-----------------------------------+
                  | **1**                             | set JMS as carrier technology     |
                  +-----------------------------------+-----------------------------------+
                  | **2**                             | set all JMS specific parameters   |
                  +-----------------------------------+-----------------------------------+
                  | **3**                             | the context factory, in this case |
                  |                                   | from JBOSS (it requires the       |
                  |                                   | dependency                        |
                  |                                   | org.jboss:jboss-remote-naming:2.0 |
                  |                                   | .4.Final                          |
                  |                                   | or a different version to be in   |
                  |                                   | the directory ``$APEX_HOME/lib``  |
                  |                                   | or ``%APEX_HOME%\lib``            |
                  +-----------------------------------+-----------------------------------+
                  | **4**                             | a connection factory for the JMS  |
                  |                                   | connection                        |
                  +-----------------------------------+-----------------------------------+
                  | **5**                             | URL with host and port of the JMS |
                  |                                   | provider                          |
                  +-----------------------------------+-----------------------------------+
                  | **6**                             | access credentials, user name     |
                  +-----------------------------------+-----------------------------------+
                  | **7**                             | access credentials, user password |
                  +-----------------------------------+-----------------------------------+
                  | **8**                             | the JMS topic to write to         |
                  +-----------------------------------+-----------------------------------+
                  | **9**                             | set object messaging to ``false`` |
                  |                                   | means it sends JSON text          |
                  +-----------------------------------+-----------------------------------+

JMS Output with Object
======================

               .. container:: paragraph

                  To configure APEX for JMS objects on the output
                  interface use the same configuration as above (for
                  output). Simply change the ``objectMessageSending``
                  parameter to ``true``.

Websocket (WS) IO
#################

            .. container:: paragraph

               APEX supports the Websockets as input as well as output.
               WS IO is supported by the APEX Websocket plugin. This
               carrier technology does only support uni-directional
               communication. APEX will not send events to a Websocket
               input and any event sent to a Websocket output will
               result in an error log.

            .. container:: paragraph

               The input can be configured as client (APEX connects to
               an existing Websocket server) or server (APEX starts a
               Websocket server). The same applies to the output. Input
               and output can both use a client or a server
               configuration, or separate configurations (input as
               client and output as server, input as server and output
               as client). Each configuration should use its own
               dedicated port to avoid any communication loops. The
               configuration of a Websocket client is the same for input
               and output. The configuration of a Websocket server is
               the same for input and output.

Websocket Client
================

               .. container:: paragraph

                  APEX will connect to a given Websocket server. As
                  input, it will receive events from the server but not
                  send any events. As output, it will send events to the
                  server and any event received from the server will
                  result in an error log.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "WEBSOCKET", (1)
                          "parameterClassName" :
                          "org.onap.policy.apex.plugins.event.carrier.websocket.WEBSOCKETCarrierTechnologyParameters",
                          "parameters" : {
                            "host" : "localhost", (2)
                            "port" : 42451 (3)
                          }
                        }

               .. container:: colist arabic

                  +-------+------------------------------------------------------+
                  | **1** | set Websocket as carrier technology                  |
                  +-------+------------------------------------------------------+
                  | **2** | the host name on which a Websocket server is running |
                  +-------+------------------------------------------------------+
                  | **3** | the port of that Websocket server                    |
                  +-------+------------------------------------------------------+

Websocket Server
================

               .. container:: paragraph

                  APEX will start a Websocket server, which will accept
                  any Websocket clients to connect. As input, it will
                  receive events from the server but not send any
                  events. As output, it will send events to the server
                  and any event received from the server will result in
                  an error log.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "WEBSOCKET", (1)
                          "parameterClassName" :
                          "org.onap.policy.apex.plugins.event.carrier.websocket.WEBSOCKETCarrierTechnologyParameters",
                          "parameters" : {
                            "wsClient" : false, (2)
                            "port"     : 42450 (3)
                          }
                        }

               .. container:: colist arabic

                  +-------+------------------------------------------------------------+
                  | **1** | set Websocket as carrier technology                        |
                  +-------+------------------------------------------------------------+
                  | **2** | disable client, so that APEX will start a Websocket server |
                  +-------+------------------------------------------------------------+
                  | **3** | the port for the Websocket server APEX will start          |
                  +-------+------------------------------------------------------------+

REST Client IO
##############

            .. container:: paragraph

               APEX can act as REST client on the input as well as on
               the output interface. The media type is
               ``application/json``, so this plugin only works with
               the JSON Event protocol.

REST Client Input
=================

               .. container:: paragraph

                  APEX will connect to a given URL to receive events,
                  but not send any events. The server is polled, i.e.
                  APEX will do an HTTP GET, take the result, and then do
                  the next GET. Any required timing needs to be handled
                  by the server configured via the URL. For instance,
                  the server could support a wait timeout via the URL as
                  ``?timeout=100ms``.
                  The httpCodeFilter is used for filtering the status
                  code, and it can be configured as a regular expression
                  string. The default httpCodeFilter is "[2][0-9][0-9]"
                  - for successful response codes.
                  The response with HTTP status code that matches the
                  given regular expression is forwarded to the task,
                  otherwise it is logged as a failure.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "RESTCLIENT", (1)
                          "parameterClassName" :
                            "org.onap.policy.apex.plugins.event.carrier.restclient.RESTClientCarrierTechnologyParameters",
                          "parameters" : {
                            "url" : "http://example.org:8080/triggers/events", (2)
                            "httpMethod": "GET", (3)
                            "httpCodeFilter" : "[2][0-9][0-9]", (4)
                             "httpHeaders" : [ (5)
                                ["Keep-Alive", "300"],
                                ["Cache-Control", "no-cache"]
                             ]
                          }
                        }

               .. container:: colist arabic

                  +-------+--------------------------------------------------+
                  | **1** | set REST client as carrier technology            |
                  +-------+--------------------------------------------------+
                  | **2** | the URL of the HTTP server for events            |
                  +-------+--------------------------------------------------+
                  | **3** | the HTTP method to use (GET/PUT/POST/DELETE),    |
                  |       | optional, defaults to GET                        |
                  +-------+--------------------------------------------------+
                  | **4** | use HTTP CODE FILTER for filtering status code,  |
                  |       | optional, defaults to [2][0-9][0-9]              |
                  +-------+--------------------------------------------------+
                  | **5** | HTTP headers to use on the REST request,         |
                  |       | optional                                         |
                  +-------+--------------------------------------------------+

REST Client Output
==================

               .. container:: paragraph

                  APEX will connect to a given URL to send events, but
                  not receive any events. The default HTTP operation is
                  POST (no configuration required). To change it to PUT
                  simply add the configuration parameter (as shown in
                  the example below).
                  The URL can be configured statically or tagged
                  as ``?example.{site}.org:8080/{trig}/events``,
                  all tags such as ``site`` and ``trig`` in the URL
                  need to be set in the properties object available to
                  the tasks. In addition, the keys should exactly match
                  with the tags defined in url. The scope of the properties
                  object is per HTTP call. Hence, key/value pairs set
                  in the properties object by task are only available
                  for that specific HTTP call.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters" : {
                          "carrierTechnology" : "RESTCLIENT", (1)
                          "parameterClassName" :
                            "org.onap.policy.apex.plugins.event.carrier.restclient.RESTClientCarrierTechnologyParameters",
                          "parameters" : {
                            "url" : "http://example.com:8888/actions/events", (2)
                            "url" : "http://example.{site}.com:8888/{trig}/events", (2')
                            "httpMethod" : "PUT". (3)
                            "httpHeaders" : [ (4)
                               ["Keep-Alive", "300"],
                               ["Cache-Control", "no-cache"]
                            ]                          }
                        }

               .. container:: colist arabic

                  +-------+--------------------------------------------------+
                  | **1** | set REST client as carrier technology            |
                  +-------+--------------------------------------------------+
                  | **2** | the static URL of the HTTP server for events     |
                  +-------+--------------------------------------------------+
                  | **2'**| the tagged URL of the HTTP server for events     |
                  +-------+--------------------------------------------------+
                  | **3** | the HTTP method to use (GET/PUT/POST/DELETE),    |
                  |       | optional, defaults to POST                       |
                  +-------+--------------------------------------------------+
                  | **4** | HTTP headers to use on the REST request,         |
                  |       | optional                                         |
                  +-------+--------------------------------------------------+

REST Server IO
##############

            .. container:: paragraph

               APEX supports a REST server for input and output.

            .. container:: paragraph

               The REST server plugin always uses a synchronous mode. A
               client does a HTTP GET on the APEX REST server with the
               input event and receives the generated output event in
               the server reply. This means that for the REST server
               there has to always to be an input with an associated
               output. Input or output only are not permitted.

            .. container:: paragraph

               The plugin will start a Grizzly server as REST server for
               a normal APEX engine. If the APEX engine is executed as a
               servlet, for instance inside Tomcat, then Tomcat will be
               used as REST server (this case requires configuration on
               Tomcat as well).

            .. container:: paragraph

               Some configuration restrictions apply for all scenarios:

            .. container:: ulist

               -  Minimum port: 1024

               -  Maximum port: 65535

               -  The media type is ``application/json``, so this plugin
                  only works with the JSON Event protocol.

            .. container:: paragraph

               The URL the client calls is created using

            .. container:: ulist

               -  the configured host and port, e.g.
                  ``http://localhost:12345``

               -  the standard path, e.g. ``/apex/``

               -  the name of the input/output, e.g. ``FirstConsumer/``

               -  the input or output name, e.g. ``EventIn``.

            .. container:: paragraph

               The examples above lead to the URL
               ``http://localhost:12345/apex/FirstConsumer/EventIn``.

            .. container:: paragraph

               A client can also get status information of the REST
               server using ``/Status``, e.g.
               ``http://localhost:12345/apex/FirstConsumer/Status``.

REST Server Stand-alone
=======================

               .. container:: paragraph

                  We need to configure a REST server input and a REST
                  server output. Input and output are associated with
                  each other via there name.

               .. container:: paragraph

                  Timeouts for REST calls need to be set carefully. If
                  they are too short, the call might timeout before a
                  policy finished creating an event.

               .. container:: paragraph

                  The following example configures the input named as
                  ``MyConsumer`` and associates an output named
                  ``MyProducer`` with it.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventInputParameters": {
                          "MyConsumer": {
                            "carrierTechnologyParameters" : {
                              "carrierTechnology" : "RESTSERVER", (1)
                              "parameterClassName" :
                                "org.onap.policy.apex.plugins.event.carrier.restserver.RESTServerCarrierTechnologyParameters",
                              "parameters" : {
                                "standalone" : true, (2)
                                "host" : "localhost", (3)
                                "port" : 12345 (4)
                              }
                            },
                            "eventProtocolParameters":{
                              "eventProtocol" : "JSON" (5)
                            },
                            "synchronousMode"    : true, (6)
                            "synchronousPeer"    : "MyProducer", (7)
                            "synchronousTimeout" : 500 (8)
                          }
                        }

               .. container:: colist arabic

                  +-------+---------------------------------------+
                  | **1** | set REST server as carrier technology |
                  +-------+---------------------------------------+
                  | **2** | set the server as stand-alone         |
                  +-------+---------------------------------------+
                  | **3** | set the server host                   |
                  +-------+---------------------------------------+
                  | **4** | set the server listen port            |
                  +-------+---------------------------------------+
                  | **5** | use JSON event protocol               |
                  +-------+---------------------------------------+
                  | **6** | activate synchronous mode             |
                  +-------+---------------------------------------+
                  | **7** | associate an output ``MyProducer``    |
                  +-------+---------------------------------------+
                  | **8** | set a timeout of 500 milliseconds     |
                  +-------+---------------------------------------+

               .. container:: paragraph

                  The following example configures the output named as
                  ``MyProducer`` and associates the input ``MyConsumer``
                  with it. Note that for the output there are no more
                  paramters (such as host or port), since they are
                  already configured in the associated input

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventOutputParameters": {
                          "MyProducer": {
                            "carrierTechnologyParameters":{
                              "carrierTechnology" : "RESTSERVER",
                              "parameterClassName" :
                                "org.onap.policy.apex.plugins.event.carrier.restserver.RESTServerCarrierTechnologyParameters"
                            },
                            "eventProtocolParameters":{
                              "eventProtocol" : "JSON"
                            },
                            "synchronousMode"    : true,
                            "synchronousPeer"    : "MyConsumer",
                            "synchronousTimeout" : 500
                          }
                        }

REST Server Stand-alone, multi input
====================================

               .. container:: paragraph

                  Any number of input/output pairs for REST servers can
                  be configured. For instance, we can configure an input
                  ``FirstConsumer`` with output ``FirstProducer`` and an
                  input ``SecondConsumer`` with output
                  ``SecondProducer``. Important is that there is always
                  one pair of input/output.

REST Server Stand-alone in Servlet
==================================

               .. container:: paragraph

                  If APEX is executed as a servlet, e.g. inside Tomcat,
                  the configuration becomes easier since the plugin can
                  now use Tomcat as the REST server. In this scenario,
                  there are not parameters (port, host, etc.) and the
                  key ``standalone`` must not be used (or set to false).

               .. container:: paragraph

                  For the Tomcat configuration, we need to add the REST
                  server plugin, e.g.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        <servlet>
                          ...
                          <init-param>
                            ...
                            <param-value>org.onap.policy.apex.plugins.event.carrier.restserver</param-value>
                          </init-param>
                          ...
                        </servlet>

REST Requestor IO
#################

            .. container:: paragraph

               APEX can act as REST requestor on the input as well as on
               the output interface. The media type is
               ``application/json``, so this plugin only works with
               the JSON Event protocol. This plugin allows APEX to send REST requests
               and to receive the reply of that request without tying up APEX resources
               while the request is being processed. The REST Requestor pairs a REST
               requestor producer and consumer together to handle the REST request
               and response. The REST request is created from an APEX output event
               and the REST response is input into APEX as a new input event.

REST Requestor Output (REST Request Producer)
=============================================

               .. container:: paragraph

                  APEX sends a REST request when events are output by APEX, the REST
                  request configuration is specified on the REST Request Consumer (see
                  below).

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters": {
                          "carrierTechnology": "RESTREQUESTOR", (1)
                          "parameterClassName": "org.onap.policy.apex.plugins.event.carrier.restrequestor.RESTRequestorCarrierTechnologyParameters"
                        },

               .. container:: colist arabic

                  +-------+------------------------------------------+
                  | **1** | set REST requestor as carrier technology |
                  +-------+------------------------------------------+

               .. container:: paragraph

                  The settings below are required on the producer to
                  define the event that triggers the REST request and
                  to specify the peered consumer configuration for the
                  REST request, for example:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventNameFilter": "GuardRequestEvent", (1)
                        "requestorMode": true, (2)
                        "requestorPeer": "GuardRequestorConsumer", (3)
                        "requestorTimeout": 500 (4)

               .. container:: colist arabic

                  +-------+-------------------------------------------+
                  | **1** | a filter on the event                     |
                  +-------+-------------------------------------------+
                  | **2** | requestor mode must be set to *true*      |
                  +-------+-------------------------------------------+
                  | **3** | the peered consumer for REST requests,    |
                  |       | that consumer specifies the full          |
                  |       | configuration for REST requests           |
                  +-------+-------------------------------------------+
                  | **4** | the request timeout in milliseconds,      |
                  |       | overridden by timeout on consumer if that |
                  |       | is set, optional defaults to 500          |
                  |       | millisconds                               |
                  +-------+-------------------------------------------+

REST Requestor Input (REST Request Consumer)
============================================

               .. container:: paragraph

                  APEX will connect to a given URL to issue a REST request and
                  wait for a REST response.
                  The URL can be configured statically or tagged
                  as ``?example.{site}.org:8080/{trig}/events``,
                  all tags such as ``site`` and ``trig`` in the URL
                  need to be set in the properties object available to
                  the tasks. In addition, the keys should exactly match
                  with the tags defined in url. The scope of the properties
                  object is per HTTP call. Hence, key/value pairs set
                  in the properties object by task are only available
                  for that specific HTTP call.
                  The httpCodeFilter is used for filtering the status
                  code, and it can be configured as a regular expression
                  string. The default httpCodeFilter is "[2][0-9][0-9]"
                  - for successful response codes.
                  The response with HTTP status code that matches the
                  given regular expression is forwarded to the task,
                  otherwise it is logged as a failure.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters": {
                          "carrierTechnology": "RESTREQUESTOR", (1)
                          "parameterClassName": "org.onap.policy.apex.plugins.event.carrier.restrequestor.RESTRequestorCarrierTechnologyParameters",
                          "parameters": {
                            "url": "http://localhost:54321/some/path/to/rest/resource", (2)
                            "url": "http://localhost:54321/{site}/path/to/rest/{resValue}", (2')
                            "httpMethod": "POST", (3)
                            "requestorMode": true, (4)
                            "requestorPeer": "GuardRequestorProducer", (5)
                            "restRequestTimeout": 2000, (6)
                            "httpCodeFilter" : "[2][0-9][0-9]" (7)
                            "httpHeaders" : [ (8)
                               ["Keep-Alive", "300"],
                               ["Cache-Control", "no-cache"]
                            ]                          }
                        },

               .. container:: colist arabic

                  +-------+--------------------------------------------------+
                  | **1** | set REST requestor as carrier technology         |
                  +-------+--------------------------------------------------+
                  | **2** | the static URL of the HTTP server for events     |
                  +-------+--------------------------------------------------+
                  | **2'**| the tagged URL of the HTTP server for events     |
                  +-------+--------------------------------------------------+
                  | **3** | the HTTP method to use (GET/PUT/POST/DELETE),    |
                  |       | optional, defaults to GET                        |
                  +-------+--------------------------------------------------+
                  | **4** | requestor mode must be set to *true*             |
                  +-------+--------------------------------------------------+
                  | **5** | the peered producer for REST requests, that      |
                  |       | producer specifies the APEX output event that    |
                  |       | triggers the REST request                        |
                  +-------+--------------------------------------------------+
                  | **6** | request timeout in milliseconds, overrides any   |
                  |       | value set in the REST Requestor Producer,        |
                  |       | optional, defaults to 500 millisconds            |
                  +-------+--------------------------------------------------+
                  | **7** | use HTTP CODE FILTER for filtering status code   |
                  |       | optional, defaults to [2][0-9][0-9]              |
                  +-------+--------------------------------------------------+
                  | **8** | HTTP headers to use on the REST request,         |
                  |       | optional                                         |
                  +-------+--------------------------------------------------+

               .. container:: paragraph

                  Further settings may be required on the consumer to
                  define the input event that is produced and forwarded into
                  APEX, for example:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventName": "GuardResponseEvent", (1)
                        "eventNameFilter": "GuardResponseEvent" (2)

               .. container:: colist arabic

                  +-------+---------------------------+
                  | **1** | the event name            |
                  +-------+---------------------------+
                  | **2** | a filter on the event     |
                  +-------+---------------------------+

gRPC IO
#######

            .. container:: paragraph

               APEX can send requests over gRPC at the output side, and get back
               response at the input side. This can be used to send requests to CDS
               over gRPC. The media type is ``application/json``, so this plugin
               only works with the JSON Event protocol.

gRPC Output
===========

               .. container:: paragraph

                  APEX will connect to a given host to send a request over
                  gRPC.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters": {
                          "carrierTechnology": "GRPC", (1)
                          "parameterClassName": "org.onap.policy.apex.plugins.event.carrier.grpc.GrpcCarrierTechnologyParameters",
                          "parameters": {
                            "host": "cds-blueprints-processor-grpc", (2)
                            "port": 9111, (2')
                            "username": "ccsdkapps", (3)
                            "password": ccsdkapps, (4)
                            "timeout" : 10 (5)
                          }
                        },

               .. container:: colist arabic

                  +-------+--------------------------------------------------+
                  | **1** | set GRPC as carrier technology                   |
                  +-------+--------------------------------------------------+
                  | **2** | the host to which request is sent                |
                  +-------+--------------------------------------------------+
                  | **2'**| the value for port                               |
                  +-------+--------------------------------------------------+
                  | **3** | username required to initiate connection         |
                  +-------+--------------------------------------------------+
                  | **4** | password required to initiate connection         |
                  +-------+--------------------------------------------------+
                  | **5** | the timeout value for completing the request     |
                  +-------+--------------------------------------------------+

               .. container:: paragraph

                  Further settings are required on the producer to
                  define the event that is requested, for example:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventName": "GRPCRequestEvent", (1)
                        "eventNameFilter": "GRPCRequestEvent", (2)
                        "requestorMode": true, (3)
                        "requestorPeer": "GRPCRequestConsumer", (4)
                        "requestorTimeout": 500 (5)

               .. container:: colist arabic

                  +-------+---------------------------+
                  | **1** | the event name            |
                  +-------+---------------------------+
                  | **2** | a filter on the event     |
                  +-------+---------------------------+
                  | **3** | the mode of the requestor |
                  +-------+---------------------------+
                  | **4** | a peer for the requestor  |
                  +-------+---------------------------+
                  | **5** | a general request timeout |
                  +-------+---------------------------+

gRPC Input
==========

               .. container:: paragraph

                  APEX will connect to the host specified in the producer
                  side, anad take in response back at the consumer side.

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "carrierTechnologyParameters": {
                          "carrierTechnology": "GRPC", (1)
                          "parameterClassName": "org.onap.policy.apex.plugins.event.carrier.grpc.GrpcCarrierTechnologyParameters"
                        },

               .. container:: colist arabic

                  +-------+------------------------------------------+
                  | **1** | set GRPC as carrier technology           |
                  +-------+------------------------------------------+

               .. container:: paragraph

                  Further settings are required on the consumer to
                  define the event that is requested, for example:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventNameFilter": "GRPCResponseEvent", (1)
                        "requestorMode": true, (2)
                        "requestorPeer": "GRPCRequestProducer", (3)
                        "requestorTimeout": 500 (4)

               .. container:: colist arabic

                  +-------+---------------------------+
                  | **1** | a filter on the event     |
                  +-------+---------------------------+
                  | **2** | the mode of the requestor |
                  +-------+---------------------------+
                  | **3** | a peer for the requestor  |
                  +-------+---------------------------+
                  | **4** | a general request timeout |
                  +-------+---------------------------+

Event Protocols, Format and Encoding
------------------------------------

         .. container:: paragraph

            Event protocols define what event formats APEX can receive
            (input) and should send (output). They can be used in any
            combination for input and output, unless further restricted
            by a carrier technology plugin (for instance for JMS
            output). There can only be 1 event protocol per event
            plugin.

         .. container:: paragraph

            Supported *input* event protocols are:

         .. container:: ulist

            -  JSON, the event as a JSON string

            -  APEX, an APEX event

            -  JMS object, the event as a JMS object,

            -  JMS text, the event as a JMS text,

            -  XML, the event as an XML string,

            -  YAML, the event as YAML text

         .. container:: paragraph

            Supported *output* event protocols are:

         .. container:: ulist

            -  JSON, the event as a JSON string

            -  APEX, an APEX event

            -  JMS object, the event as a JMS object,

            -  JMS text, the event as a JMS text,

            -  XML, the event as an XML string,

            -  YAML, the event as YAML text

         .. container:: paragraph

            New event protocols can be added as plugins to APEX or
            developed outside APEX and added to an APEX deployment.

JSON Event
##########

            .. container:: paragraph

               The event protocol for JSON encoding does not require a
               specific plugin, it is supported by default. Furthermore,
               there is no difference in the configuration for the input
               and output interface.

            .. container:: paragraph

               For an input, APEX requires a well-formed JSON string.
               Well-formed here means according to the definitions of a
               policy. Any JSON string that is not defined as a trigger
               event (consume) will not be consumed (errors will be
               thrown). For output JSON events, APEX will always produce
               valid JSON strings according to the definition in the
               policy model.

            .. container:: paragraph

               The following JSON shows the configuration.

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventProtocolParameters":{
                       "eventProtocol" : "JSON"
                     }

            .. container:: paragraph

               For JSON events, there are a few more optional
               parameters, which allow to define a mapping for standard
               event fields. An APEX event must have the fields
               ``name``, ``version``, ``source``, and ``target``
               defined. Sometimes it is not possible to configure a
               trigger or actioning system to use those fields. However,
               they might be in an event generated outside APEX (or used
               outside APEX) just with different names. To configure
               APEX to map between the different event names, simply add
               the following parameters to a JSON event:

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventProtocolParameters":{
                       "eventProtocol" : "JSON",
                       "nameAlias"     : "policyName", (1)
                       "versionAlias"  : "policyVersion", (2)
                       "sourceAlias"   : "from", (3)
                       "targetAlias"   : "to", (4)
                       "nameSpaceAlias": "my.name.space" (5)
                     }

            .. container:: colist arabic

               +-----------------------------------+-----------------------------------+
               | **1**                             | mapping for the ``name`` field,   |
               |                                   | here from a field called          |
               |                                   | ``policyName``                    |
               +-----------------------------------+-----------------------------------+
               | **2**                             | mapping for the ``version``       |
               |                                   | field, here from a field called   |
               |                                   | ``policyVersion``                 |
               +-----------------------------------+-----------------------------------+
               | **3**                             | mapping for the ``source`` field, |
               |                                   | here from a field called ``from`` |
               |                                   | (only for an input event)         |
               +-----------------------------------+-----------------------------------+
               | **4**                             | mapping for the ``target`` field, |
               |                                   | here from a field called ``to``   |
               |                                   | (only for an output event)        |
               +-----------------------------------+-----------------------------------+
               | **5**                             | mapping for the ``nameSpace``     |
               |                                   | field, here from a field called   |
               |                                   | ``my.name.space``                 |
               +-----------------------------------+-----------------------------------+

APEX Event
##########
            .. container:: paragraph

               The event protocol for APEX events does not require a
               specific plugin, it is supported by default. Furthermore,
               there is no difference in the configuration for the input
               and output interface.

            .. container:: paragraph

               For input and output APEX uses APEX events.

            .. container:: paragraph

               The following JSON shows the configuration.

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventProtocolParameters":{
                       "eventProtocol" : "APEX"
                     }

JMS Event
#########

            .. container:: paragraph

               The event protocol for JMS is provided by the APEX JMS
               plugin. The plugin supports encoding as JSON text or as
               object. There is no difference in the configuration for
               the input and output interface.

JMS Text
========
               .. container:: paragraph

                  If used as input, APEX will take a JMS message and
                  extract a JSON string, then proceed as if a JSON event
                  was received. If used as output, APEX will take the
                  event produced by a policy, create a JSON string, and
                  then wrap it into a JMS message.

               .. container:: paragraph

                  The configuration for JMS text is as follows:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventProtocolParameters":{
                          "eventProtocol" : "JMSTEXT",
                          "parameterClassName" :
                            "org.onap.policy.apex.plugins.event.protocol.jms.JMSTextEventProtocolParameters"
                        }

JMS Object
==========
               .. container:: paragraph

                  If used as input, APEX will will take a JMS message,
                  extract a Java Bean from the ``ObjectMessage``
                  message, construct an APEX event and put the bean on
                  the APEX event as a parameter. If used as output, APEX
                  will take the event produced by a policy, create a
                  Java Bean and send it as a JMS message.

               .. container:: paragraph

                  The configuration for JMS object is as follows:

               .. container:: listingblock

                  .. container:: content

                     .. code::

                        "eventProtocolParameters":{
                          "eventProtocol" : "JMSOBJECT",
                          "parameterClassName" :
                            "org.onap.policy.apex.plugins.event.protocol.jms.JMSObjectEventProtocolParameters"
                        }

YAML Event
##########

            .. container:: paragraph

               The event protocol for YAML is provided by the APEX YAML
               plugin. There is no difference in the configuration for
               the input and output interface.

            .. container:: paragraph

               If used as input, APEX will consume events as YAML and
               map them to policy trigger events. Not well-formed YAML
               and not understood trigger events will be rejected. If
               used as output, APEX produce YAML encoded events from the
               event a policy produces. Those events will always be
               well-formed according to the definition in the policy
               model.

            .. container:: paragraph

               The following code shows the configuration.

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventProtocolParameters":{
                       "eventProtocol" : "XML",
                       "parameterClassName" :
                           "org.onap.policy.apex.plugins.event.protocol.yaml.YamlEventProtocolParameters"
                     }

XML Event
#########
            .. container:: paragraph

               The event protocol for XML is provided by the APEX XML
               plugin. There is no difference in the configuration for
               the input and output interface.

            .. container:: paragraph

               If used as input, APEX will consume events as XML and map
               them to policy trigger events. Not well-formed XML and
               not understood trigger events will be rejected. If used
               as output, APEX produce XML encoded events from the event
               a policy produces. Those events will always be
               well-formed according to the definition in the policy
               model.

            .. container:: paragraph

               The following code shows the configuration.

            .. container:: listingblock

               .. container:: content

                  .. code::

                     "eventProtocolParameters":{
                       "eventProtocol" : "XML",
                       "parameterClassName" :
                           "org.onap.policy.apex.plugins.event.protocol.xml.XMLEventProtocolParameters"
                     }

A configuration example
-----------------------

         .. container:: paragraph

            The following example loads all available plug-ins.

         .. container:: paragraph

            Events are consumed from a Websocket, APEX as client.
            Consumed event format is JSON.

         .. container:: paragraph

            Events are produced to Kafka. Produced event format is XML.

         .. container:: listingblock

            .. container:: content

               .. code::

                  {
                    "engineServiceParameters" : {
                      "name"          : "MyApexEngine",
                      "version"        : "0.0.1",
                      "id"             :  45,
                      "instanceCount"  : 4,
                      "deploymentPort" : 12345,
                      "engineParameters"    : {
                        "executorParameters" : {
                          "JAVASCRIPT" : {
                            "parameterClassName" :
                                "org.onap.policy.apex.plugins.executor.javascript.JavascriptExecutorParameters"
                          },
                          "JYTHON" : {
                            "parameterClassName" :
                                "org.onap.policy.apex.plugins.executor.jython.JythonExecutorParameters"
                          },
                          "JRUBY" : {
                            "parameterClassName" :
                                "org.onap.policy.apex.plugins.executor.jruby.JrubyExecutorParameters"
                          },
                          "JAVA" : {
                            "parameterClassName" :
                                "org.onap.policy.apex.plugins.executor.java.JavaExecutorParameters"
                          },
                          "MVEL" : {
                            "parameterClassName" :
                                "org.onap.policy.apex.plugins.executor.mvel.MVELExecutorParameters"
                          }
                        },
                        "contextParameters" : {
                          "parameterClassName" :
                              "org.onap.policy.apex.context.parameters.ContextParameters",
                          "schemaParameters" : {
                            "Avro":{
                               "parameterClassName" :
                                   "org.onap.policy.apex.plugins.context.schema.avro.AvroSchemaHelperParameters"
                            }
                          }
                        }
                      }
                    },
                    "producerCarrierTechnologyParameters" : {
                      "carrierTechnology" : "KAFKA",
                      "parameterClassName" :
                          "org.onap.policy.apex.plugins.event.carrier.kafka.KAFKACarrierTechnologyParameters",
                      "parameters" : {
                        "bootstrapServers"  : "localhost:49092",
                        "acks"              : "all",
                        "retries"           : 0,
                        "batchSize"         : 16384,
                        "lingerTime"        : 1,
                        "bufferMemory"      : 33554432,
                        "producerTopic"     : "apex-out",
                        "keySerializer"     : "org.apache.kafka.common.serialization.StringSerializer",
                        "valueSerializer"   : "org.apache.kafka.common.serialization.StringSerializer"
                      }
                    },
                    "producerEventProtocolParameters" : {
                      "eventProtocol" : "XML",
                           "parameterClassName" :
                               "org.onap.policy.apex.plugins.event.protocol.xml.XMLEventProtocolParameters"
                    },
                    "consumerCarrierTechnologyParameters" : {
                      "carrierTechnology" : "WEBSOCKET",
                      "parameterClassName" :
                          "org.onap.policy.apex.plugins.event.carrier.websocket.WEBSOCKETCarrierTechnologyParameters",
                      "parameters" : {
                        "host" : "localhost",
                        "port" : 88888
                      }
                    },
                    "consumerEventProtocolParameters" : {
                      "eventProtocol" : "JSON"
                    }
                  }

Engine and Applications of the APEX System
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Introduction to APEX Engine and Applications
--------------------------------------------

         .. container:: paragraph

            The core of APEX is the APEX Engine, also known as the APEX
            Policy Engine or the APEX PDP (since it is in fact a Policy
            Decision Point). Beside this engine, an APEX system comes
            with a few applications intended to help with policy
            authoring, deployment, and execution.

         .. container:: paragraph

            The engine itself and most applications are started from the
            command line with command line arguments. This is called a
            Command Line Interface (CLI). Some applications require an
            installation on a webserver, as for instance the REST
            Editor. Those applications can be accessed via a web
            browser.

         .. container:: paragraph

            You can also use the available APEX APIs and applications to
            develop other applications as required. This includes policy
            languages (and associated parsers and compilers /
            interpreters), GUIs to access APEX or to define policies,
            clients to connect to APEX, etc.

         .. container:: paragraph

            For this documentation, we assume an installation of APEX as
            a full system based on a current ONAP release.

CLI on Unix, Windows, and Cygwin
--------------------------------

         .. container:: paragraph

            A note on APEX CLI applications: all applications and the
            engine itself have been deployed and tested on different
            operating systems: Red Hat, Ubuntu, Debian, Mac OSX,
            Windows, Cygwin. Each operating system comes with its own
            way of configuring and executing Java. The main items here
            are:

         .. container:: ulist

            -  For UNIX systems (RHL, Ubuntu, Debian, Mac OSX), the
               provided bash scripts work as expected with absolute
               paths (e.g.
               ``/opt/app/policy/apex-pdp/apex-pdp-2.0.0-SNAPSHOT/examples``),
               indirect and linked paths (e.g. ``../apex/apex``), and
               path substitutions using environment settings (e.g.
               ``$APEX_HOME/bin/``)

            -  For Windows systems, the provided batch files (``.bat``)
               work as expected with with absolute paths (e.g.
               ``C:\apex\apex-2.0.0-SNAPSHOT\examples``), and path
               substitutions using environment settings (e.g.
               ``%APEX_HOME%\bin\``)

            -  For Cygwin system we assume a standard Cygwin
               installation with standard tools (mainly bash) using a
               Windows Java installation. This means that the bash
               scripts can be used as in UNIX, however any argument
               pointing to files and directories need to use either a
               DOS path (e.g.
               ``C:\apex\apex-2.0.0-SNAPSHOT\examples\config...``) or
               the command ``cygpath`` with a mixed option. The reason
               for that is: Cygwin executes Java using UNIX paths but
               then runs Java as a DOS/WINDOWS process, which requires
               DOS paths for file access.

The APEX Engine
---------------

         .. container:: paragraph

            The APEX engine can be started in different ways, depending
            your requirements. All scripts are located in the APEX *bin*
            directory

         .. container:: paragraph

            On UNIX and Cygwin systems use:

         .. container:: ulist

            -  ``apexEngine.sh`` - this script will

               .. container:: ulist

                  -  Test if ``$APEX_USER`` is set and if the user
                     exists, terminate with an error otherwise

                  -  Test if ``$APEX_HOME`` is set. If not set, it will
                     use the default setting as
                     ``/opt/app/policy/apex-pdp/apex-pdp``. Then the set
                     directory is tested to exist, the script will
                     terminate if not.

                  -  When all tests are passed successfully, the script
                     will call ``apexApps.sh`` with arguments to start
                     the APEX engine.

            -  ``apexApps.sh engine`` - this is the general APEX
               application launcher, which will

               .. container:: ulist

                  -  Start the engine with the argument ``engine``

                  -  Test if ``$APEX_HOME`` is set and points to an
                     existing directory. If not set or directory does
                     not exist, script terminates.

                  -  Not test for any settings of ``$APEX_USER``.

         .. container:: paragraph

            On Windows systems use ``apexEngine.bat`` and
            ``apexApps.bat engine`` respectively. Note: none of the
            windows batch files will test for ``%APEX_USER%``.

         .. container:: paragraph

            Summary of alternatives to start the APEX Engine:

         +--------------------------------------------------------+----------------------------------------------------------+
         | Unix, Cygwin                                           | Windows                                                  |
         +========================================================+==========================================================+
         | .. container::                                         | .. container::                                           |
         |                                                        |                                                          |
         |    .. container:: listingblock                         |    .. container:: listingblock                           |
         |                                                        |                                                          |
         |       .. container:: content                           |       .. container:: content                             |
         |                                                        |                                                          |
         |          .. code::                                     |          .. code::                                       |
         |                                                        |                                                          |
         |             # $APEX_HOME/bin/apexEngine.sh [args]      |             > %APEX_HOME%\bin\apexEngine.bat [args]      |
         |             # $APEX_HOME/bin/apexApps.sh engine [args] |             > %APEX_HOME%\bin\apexApps.bat engine [args] |
         +--------------------------------------------------------+----------------------------------------------------------+

         .. container:: paragraph

            The APEX engine comes with a few CLI arguments, the main one is for setting
            the tosca policy file for execution. The tosca policy file is
            always required. The option ``-h`` prints a help screen.

         .. container:: listingblock

            .. container:: content

               .. code::

                  usage: org.onap.policy.apex.service.engine.main.ApexMain [options...]
                  options
                  -p,--tosca-policy-file <TOSCA_POLICY_FILE>     the full path to the ToscaPolicy file to use.
                  -h,--help                                      outputs the usage of this command
                  -v,--version                                   outputs the version of Apex

The APEX CLI Editor
-------------------

         .. container:: paragraph

            The CLI Editor allows to define policies from the command
            line. The application uses a simple language and supports
            all elements of an APEX policy. It can be used in to
            different ways:

         .. container:: ulist

            -  non-interactive, specifying a file with the commands to
               create a policy

            -  interactive, using the editors CLI to create a policy

         .. container:: paragraph

            When a policy is fully specified, the editor will generate
            the APEX core policy specification in JSON. This core
            specification is called the policy model in the APEX engine
            and can be used directly with the APEX engine.

         .. container:: paragraph

            On UNIX and Cygwin systems use:

         .. container:: ulist

            -  ``apexCLIEditor.sh`` - simply starts the CLI editor,
               arguments to the script determine the mode of the editor

            -  ``apexApps.sh cli-editor`` - simply starts the CLI
               editor, arguments to the script determine the mode of the
               editor

         .. container:: paragraph

            On Windows systems use:

         .. container:: ulist

            -  ``apexCLIEditor.bat`` - simply starts the CLI editor,
               arguments to the script determine the mode of the editor

            -  ``apexApps.bat cli-editor`` - simply starts the CLI
               editor, arguments to the script determine the mode of the
               editor

         .. container:: paragraph

            Summary of alternatives to start the APEX CLI Editor:

         +------------------------------------------------------------+--------------------------------------------------------------+
         | Unix, Cygwin                                               | Windows                                                      |
         +============================================================+==============================================================+
         | .. container::                                             | .. container::                                               |
         |                                                            |                                                              |
         |    .. container:: listingblock                             |    .. container:: listingblock                               |
         |                                                            |                                                              |
         |       .. container:: content                               |       .. container:: content                                 |
         |                                                            |                                                              |
         |          .. code::                                         |          .. code::                                           |
         |                                                            |                                                              |
         |             # $APEX_HOME/bin/apexCLIEditor.sh.sh [args]    |             > %APEX_HOME%\bin\apexCLIEditor.bat [args]       |
         |             # $APEX_HOME/bin/apexApps.sh cli-editor [args] |             > %APEX_HOME%\bin\apexApps.bat cli-editor [args] |
         +------------------------------------------------------------+--------------------------------------------------------------+

         .. container:: paragraph

            The option ``-h`` provides a help screen with all command
            line arguments.

         .. container:: listingblock

            .. container:: content

               .. code::

                  usage: org.onap.policy.apex.auth.clieditor.ApexCLIEditorMain [options...]
                  options
                   -a,--model-props-file <MODEL_PROPS_FILE>       name of the apex model properties file to use
                   -c,--command-file <COMMAND_FILE>               name of a file containing editor commands to run into the editor
                   -h,--help                                      outputs the usage of this command
                   -i,--input-model-file <INPUT_MODEL_FILE>       name of a file that contains an input model for the editor
                   -if,--ignore-failures <IGNORE_FAILURES_FLAG>   true or false, ignore failures of commands in command files and continue
                                                                  executing the command file
                   -l,--log-file <LOG_FILE>                       name of a file that will contain command logs from the editor, will log
                                                                  to standard output if not specified or suppressed with "-nl" flag
                   -m,--metadata-file <CMD_METADATA_FILE>         name of the command metadata file to use
                   -nl,--no-log                                   if specified, no logging or output of commands to standard output or log
                                                                  file is carried out
                   -nm,--no-model-output                          if specified, no output of a model to standard output or model output
                                                                  file is carried out, the user can use the "save" command in a script to
                                                                  save a model
                   -o,--output-model-file <OUTPUT_MODEL_FILE>     name of a file that will contain the output model for the editor, will
                                                                  output model to standard output if not specified or suppressed with
                                                                  "-nm" flag
                   -wd,--working-directory <WORKING_DIRECTORY>    the working directory that is the root for the CLI editor and is the
                                                                  root from which to look for included macro files

The APEX CLI Tosca Editor
-------------------------

         .. container:: paragraph

            As per the new Policy LifeCycle API, the policies are expected to be defined as ToscaServiceTemplate. The CLI Tosca Editor is an extended version of the APEX CLI Editor which can generate the policies in ToscaServiceTemplate way.

         .. container:: paragraph

            The APEX config file(.json), command file(.apex) and the tosca template skeleton(.json) file paths need to be passed as input arguments to the CLI Tosca Editor. Policy in ToscaServiceTemplate format is generated as the output. This can be used as the input to Policy API for creating policies.

         .. container:: paragraph

            On UNIX and Cygwin systems use:

         .. container:: ulist

            -  ``apexCLIToscaEditor.sh`` - starts the CLI Tosca editor,
               all the arguments supported by the basic CLI Editor are supported in addition to the mandatory arguments needed to generate ToscaServiceTemplate.

            -  ``apexApps.sh cli-tosca-editor`` - starts the CLI Tosca editor,
               all the arguments supported by the basic CLI Editor are supported in addition to the mandatory arguments needed to generate ToscaServiceTemplate.

         .. container:: paragraph

            On Windows systems use:

         .. container:: ulist

            -  ``apexCLIToscaEditor.bat`` - starts the CLI Tosca editor,
               all the arguments supported by the basic CLI Editor are supported in addition to the mandatory arguments needed to generate ToscaServiceTemplate.

            -  ``apexApps.bat cli-tosca-editor`` - starts the CLI Tosca
               editor, all the arguments supported by the basic CLI Editor are supported in addition to the mandatory arguments needed to generate ToscaServiceTemplate.

         .. container:: paragraph

            Summary of alternatives to start the APEX CLI Tosca Editor:

     +-----------------------------------------------------------------+--------------------------------------------------------------------+
     | Unix, Cygwin                                                    | Windows                                                            |
     +=================================================================+====================================================================+
     | .. container::                                                  | .. container::                                                     |
     |                                                                 |                                                                    |
     |    .. container:: listingblock                                  |    .. container:: listingblock                                     |
     |                                                                 |                                                                    |
     |       .. container:: content                                    |       .. container:: content                                       |
     |                                                                 |                                                                    |
     |          .. code::                                              |          .. code::                                                 |
     |                                                                 |                                                                    |
     |             # $APEX_HOME/bin/apexCLIToscaEditor.sh.sh [args]    |             > %APEX_HOME%\bin\apexCLIToscaEditor.bat [args]        |
     |             # $APEX_HOME/bin/apexApps.sh cli-tosca-editor [args]|             > %APEX_HOME%\bin\apexApps.bat cli-tosca-editor [args] |
     +-----------------------------------------------------------------+--------------------------------------------------------------------+

         .. container:: paragraph

            The option ``-h`` provides a help screen with all command
            line arguments.

         .. container:: listingblock

            .. container:: content

               .. code::

                  usage: org.onap.policy.apex.auth.clieditor.tosca.ApexCliToscaEditorMain [options...]
                  options
                   -a,--model-props-file <MODEL_PROPS_FILE>         name of the apex model properties file to use
                   -ac,--apex-config-file <APEX_CONFIG_FILE>        name of the file containing apex configuration details
                   -c,--command-file <COMMAND_FILE>                 name of a file containing editor commands to run into the editor
                   -h,--help                                        outputs the usage of this command
                   -i,--input-model-file <INPUT_MODEL_FILE>         name of a file that contains an input model for the editor
                   -if,--ignore-failures <IGNORE_FAILURES_FLAG>     true or false, ignore failures of commands in command files and
                                                                    continue executing the command file
                   -l,--log-file <LOG_FILE>                         name of a file that will contain command logs from the editor, will
                                                                    log to standard output if not specified or suppressed with "-nl" flag
                   -m,--metadata-file <CMD_METADATA_FILE>           name of the command metadata file to use
                   -nl,--no-log                                     if specified, no logging or output of commands to standard output or
                                                                    log file is carried out
                   -ot,--output-tosca-file <OUTPUT_TOSCA_FILE>      name of a file that will contain the output ToscaServiceTemplate
                   -t,--tosca-template-file <TOSCA_TEMPLATE_FILE>   name of the input file containing tosca template which needs to be
                                                                    updated with policy
                   -wd,--working-directory <WORKING_DIRECTORY>      the working directory that is the root for the CLI editor and is the
                                                                    root from which to look for included macro files

         .. container:: paragraph

            An example command to run the APEX CLI Tosca editor on windows machine is given below.

         .. container:: listingblock

            .. container:: content

               .. code::

                  %APEX_HOME%/\bin/\apexCLIToscaEditor.bat -c %APEX_HOME%\examples\PolicyModel.apex -ot %APEX_HOME%\examples\test.json  -l %APEX_HOME%\examples\test.log -ac %APEX_HOME%\examples\RESTServerStandaloneJsonEvent.json -t %APEX_HOME%\examples\ToscaTemplate.json


The APEX Client
---------------

         .. container:: paragraph

            The APEX Client combines the Policy Editor, the
            Monitoring Client, and the Deployment Client into a single
            application. The standard way to use the APEX Full Client is
            via an installation of the *war* file on a webserver.
            However, the Full Client can also be started via command
            line. This will start a Grizzly webserver with the *war*
            deployed. Access to the Full Client is then via the provided
            URL

         .. container:: paragraph

            On UNIX and Cygwin systems use:

         .. container:: ulist

            -  ``apexApps.sh full-client`` - simply starts the webserver
               with the Full Client

         .. container:: paragraph

            On Windows systems use:

         .. container:: ulist

            -  ``apexApps.bat full-client`` - simply starts the
               webserver with the Full Client

         .. container:: paragraph

            The option ``-h`` provides a help screen with all command
            line arguments.

         .. container:: listingblock

            .. container:: content

               .. code::

                  usage: org.onap.policy.apex.client.full.rest.ApexServicesRestMain [options...]
                  -h,--help                        outputs the usage of this command
                  -p,--port <PORT>                 port to use for the Apex Services REST calls
                  -t,--time-to-live <TIME_TO_LIVE> the amount of time in seconds that the server will run for before terminating

         .. container:: paragraph

            If the Full Client is started without any arguments the
            final messages will look similar to this:

         .. container:: listingblock

            .. container:: content

               .. code::

                  Apex Editor REST endpoint (ApexServicesRestMain: Config=[ApexServicesRestParameters: URI=http://localhost:18989/apexservices/, TTL=-1sec], State=READY) starting at http://localhost:18989/apexservices/ . . .
                  Sep 05, 2018 11:28:28 PM org.glassfish.grizzly.http.server.NetworkListener start
                  INFO: Started listener bound to [localhost:18989]
                  Sep 05, 2018 11:28:28 PM org.glassfish.grizzly.http.server.HttpServer start
                  INFO: [HttpServer] Started.
                  Apex Editor REST endpoint (ApexServicesRestMain: Config=[ApexServicesRestParameters: URI=http://localhost:18989/apexservices/, TTL=-1sec], State=RUNNING) started at http://localhost:18989/apexservices/

         .. container:: paragraph

            The last line states the URL on which the Monitoring Client
            can be accessed. The example above stated
            ``http://localhost:18989/apexservices``. In a web browser
            use the URL ``http://localhost:18989``.

The APEX Application Launcher
-----------------------------

         .. container:: paragraph

            The standard applications (Engine and CLI Editor)
            come with dedicated start scripts. For all other APEX
            applications, we provide an application launcher.

         .. container:: paragraph

            On UNIX and Cygwin systems use:

         .. container:: ulist

            -  apexApps.sh\` - simply starts the application launcher

         .. container:: paragraph

            On Windows systems use:

         .. container:: ulist

            -  ``apexApps.bat`` - simply starts the application launcher

         .. container:: paragraph

            Summary of alternatives to start the APEX application
            launcher:

         +-------------------------------------------------+---------------------------------------------------+
         | Unix, Cygwin                                    | Windows                                           |
         +=================================================+===================================================+
         | .. container::                                  | .. container::                                    |
         |                                                 |                                                   |
         |    .. container:: listingblock                  |    .. container:: listingblock                    |
         |                                                 |                                                   |
         |       .. container:: content                    |       .. container:: content                      |
         |                                                 |                                                   |
         |          .. code::                              |          .. code::                                |
         |                                                 |                                                   |
         |             # $APEX_HOME/bin/apexApps.sh [args] |             > %APEX_HOME%\bin\apexApps.bat [args] |
         +-------------------------------------------------+---------------------------------------------------+

         .. container:: paragraph

            The option ``-h`` provides a help screen with all launcher
            command line arguments.

         .. container:: listingblock

            .. container:: content

               .. code::

                  apexApps.sh - runs APEX applications

                         Usage:  apexApps.sh [options] | [<application> [<application options>]]

                         Options
                           -d <app>    - describes an application
                           -l          - lists all applications supported by this script
                           -h          - this help screen

         .. container:: paragraph

            Using ``-l`` lists all known application the launcher can
            start.

         .. container:: listingblock

            .. container:: content

               .. code::

                  apexApps.sh: supported applications:
                   --> ws-echo engine eng-monitoring full-client eng-deployment tpl-event-json model-2-cli rest-editor cli-editor ws-console

         .. container:: paragraph

            Using the ``-d <name>`` option describes the named
            application, for instance for the ``ws-console``:

         .. container:: listingblock

            .. container:: content

               .. code::

                  apexApps.sh: application 'ws-console'
                   --> a simple console sending events to APEX, connect to APEX consumer port

         .. container:: paragraph

            Launching an application is done by calling the script with
            only the application name and any CLI arguments for the
            application. For instance, starting the ``ws-echo``
            application with port ``8888``:

         .. container:: listingblock

            .. container:: content

               .. code::

                  apexApps.sh ws-echo -p 8888

Application: Create Event Templates
-----------------------------------

         .. container:: paragraph

            **Status: Experimental**

         .. container:: paragraph

            This application takes a policy model (JSON or XML encoded)
            and generates templates for events in JSON format. This can
            help when a policy defines rather complex trigger or action
            events or complex events between states. The application can
            produce events for the types: stimuli (policy trigger
            events), internal (events between policy states), and
            response (action events).

         +----------------------------------------------------------------+------------------------------------------------------------------+
         | Unix, Cygwin                                                   | Windows                                                          |
         +================================================================+==================================================================+
         | .. container::                                                 | .. container::                                                   |
         |                                                                |                                                                  |
         |    .. container:: listingblock                                 |    .. container:: listingblock                                   |
         |                                                                |                                                                  |
         |       .. container:: content                                   |       .. container:: content                                     |
         |                                                                |                                                                  |
         |          .. code::                                             |          .. code::                                               |
         |                                                                |                                                                  |
         |             # $APEX_HOME/bin/apexApps.sh tpl-event-json [args] |             > %APEX_HOME%\bin\apexApps.bat tpl-event-json [args] |
         +----------------------------------------------------------------+------------------------------------------------------------------+

         .. container:: paragraph

            The option ``-h`` provides a help screen.

         .. container:: listingblock

            .. container:: content

               .. code::

                  gen-model2event v{release-version} - generates JSON templates for events generated from a policy model
                  usage: gen-model2event
                   -h,--help                 prints this help and usage screen
                   -m,--model <MODEL-FILE>   set the input policy model file
                   -t,--type <TYPE>          set the event type for generation, one of:
                                             stimuli (trigger events), response (action
                                             events), internal (events between states)
                   -v,--version              prints the application version

         .. container:: paragraph

            The created templates are not valid events, instead they use
            some markup for values one will need to change to actual
            values. For instance, running the tool with the *Sample
            Domain* policy model as:

         .. container:: listingblock

            .. container:: content

               .. code::

                  apexApps.sh tpl-event-json -m $APEX_HOME/examples/models/SampleDomain/SamplePolicyModelJAVA.json -t stimuli

         .. container:: paragraph

            will produce the following status messages:

         .. container:: listingblock

            .. container:: content

               .. code::

                  gen-model2event: starting Event generator
                   --> model file: examples/models/SampleDomain/SamplePolicyModelJAVA.json
                   --> type: stimuli

         .. container:: paragraph

            and then run the generator application producing two event
            templates. The first template is called ``Event0000``.

         .. container:: listingblock

            .. container:: content

               .. code::

                  {
                          "name" : "Event0000",
                          "nameSpace" : "org.onap.policy.apex.sample.events",
                          "version" : "0.0.1",
                          "source" : "Outside",
                          "target" : "Match",
                          "TestTemperature" : ###double: 0.0###,
                          "TestTimestamp" : ###long: 0###,
                          "TestMatchCase" : ###integer: 0###,
                          "TestSlogan" : "###string###"
                  }

         .. container:: paragraph

            The values for the keys are marked with ``#`` and the
            expected type of the value. To create an actual stimuli
            event, all these markers need to be change to actual values,
            for instance:

         .. container:: listingblock

            .. container:: content

               .. code::

                  {
                          "name" : "Event0000",
                          "nameSpace" : "org.onap.policy.apex.sample.events",
                          "version" : "0.0.1",
                          "source" : "Outside",
                          "target" : "Match",
                          "TestTemperature" : 25,
                          "TestTimestamp" : 123456789123456789,
                          "TestMatchCase" : 1,
                          "TestSlogan" : "Testing the Match Case with Temperature 25"
                  }

Application: Convert a Policy Model to CLI Editor Commands
----------------------------------------------------------

         .. container:: paragraph

            **Status: Experimental**

         .. container:: paragraph

            This application takes a policy model (JSON or XML encoded)
            and generates commands for the APEX CLI Editor. This
            effectively reverses a policy specification realized with
            the CLI Editor.

         +-------------------------------------------------------------+---------------------------------------------------------------+
         | Unix, Cygwin                                                | Windows                                                       |
         +=============================================================+===============================================================+
         | .. container::                                              | .. container::                                                |
         |                                                             |                                                               |
         |    .. container:: listingblock                              |    .. container:: listingblock                                |
         |                                                             |                                                               |
         |       .. container:: content                                |       .. container:: content                                  |
         |                                                             |                                                               |
         |          .. code::                                          |          .. code::                                            |
         |                                                             |                                                               |
         |             # $APEX_HOME/bin/apexApps.sh model-2-cli [args] |             > %APEX_HOME%\bin\apexApps.bat model-2-cli [args] |
         +-------------------------------------------------------------+---------------------------------------------------------------+

         .. container:: paragraph

            The option ``-h`` provides a help screen.

         .. container:: listingblock

            .. container:: content

               .. code::

                  usage: gen-model2cli
                   -h,--help                 prints this help and usage screen
                   -m,--model <MODEL-FILE>   set the input policy model file
                   -sv,--skip-validation     switch of validation of the input file
                   -v,--version              prints the application version

         .. container:: paragraph

            For instance, running the tool with the *Sample Domain*
            policy model as:

         .. container:: listingblock

            .. container:: content

               .. code::

                  apexApps.sh model-2-cli -m $APEX_HOME/examples/models/SampleDomain/SamplePolicyModelJAVA.json

         .. container:: paragraph

            will produce the following status messages:

         .. container:: listingblock

            .. container:: content

               .. code::

                  gen-model2cli: starting CLI generator
                   --> model file: examples/models/SampleDomain/SamplePolicyModelJAVA.json

         .. container:: paragraph

            and then run the generator application producing all CLI
            Editor commands and printing them to standard out.

Application: Websocket Clients (Echo and Console)
-------------------------------------------------

         .. container:: paragraph

            **Status: Production**

         .. container:: paragraph

            The application launcher also provides a Websocket echo
            client and a Websocket console client. The echo client
            connects to APEX and prints all events it receives from
            APEX. The console client connects to APEX, reads input from
            the command line, and sends this input as events to APEX.

         +------------------------------------------------------------+--------------------------------------------------------------+
         | Unix, Cygwin                                               | Windows                                                      |
         +============================================================+==============================================================+
         | .. container::                                             | .. container::                                               |
         |                                                            |                                                              |
         |    .. container:: listingblock                             |    .. container:: listingblock                               |
         |                                                            |                                                              |
         |       .. container:: content                               |       .. container:: content                                 |
         |                                                            |                                                              |
         |          .. code::                                         |          .. code::                                           |
         |                                                            |                                                              |
         |             # $APEX_HOME/bin/apexApps.sh ws-echo [args]    |             > %APEX_HOME%\bin\apexApps.bat ws-echo [args]    |
         |             # $APEX_HOME/bin/apexApps.sh ws-console [args] |             > %APEX_HOME%\bin\apexApps.bat ws-console [args] |
         +------------------------------------------------------------+--------------------------------------------------------------+

         .. container:: paragraph

            The arguments are the same for both applications:

         .. container:: ulist

            -  ``-p`` defines the Websocket port to connect to (defaults
               to ``8887``)

            -  ``-s`` defines the host on which a Websocket server is
               running (defaults to ``localhost``)

         .. container:: paragraph

            A discussion on how to use these two applications to build
            an APEX system is detailed HowTo-Websockets.

APEX Logging
^^^^^^^^^^^^

Introduction to APEX Logging
----------------------------

         .. container:: paragraph

            All APEX components make extensive use of logging using the
            logging façade `SLF4J <https://www.slf4j.org/>`__ with the
            backend `Logback <https://logback.qos.ch/>`__. Both are used
            off-the-shelve, so the standard documentation and
            configuration apply to APEX logging. For details on how to
            work with logback please see the `logback
            manual <https://logback.qos.ch/manual/index.html>`__.

         .. container:: paragraph

            The APEX applications is the logback configuration file
            ``$APEX_HOME/etc/logback.xml`` (Windows:
            ``%APEX_HOME%\etc\logback.xml``). The logging backend is set
            to no debug, i.e. logs from the logging framework should be
            hidden at runtime.

         .. container:: paragraph

            The configurable log levels work as expected:

         .. container:: ulist

            -  *error* (or *ERROR*) is used for serious errors in the
               APEX runtime engine

            -  *warn* (or *WARN*) is used for warnings, which in general
               can be ignored but might indicate some deeper problems

            -  *info* (or *INFO*) is used to provide generally
               interesting messages for startup and policy execution

            -  *debug* (or *DEBUG*) provides more details on startup and
               policy execution

            -  *trace* (or *TRACE*) gives full details on every aspect
               of the APEX engine from start to end

         .. container:: paragraph

            The loggers can also be configured as expected. The standard
            configuration (after installing APEX) uses log level *info*
            on all APEX classes (components).

         .. container:: paragraph

            The applications and scripts in ``$APEX_HOME/bin`` (Windows:
            ``%APEX_HOME\bin``) are configured to use the logback
            configuration ``$APEX_HOME/etc/logback.xml`` (Windows:
            ``%APEX_HOME\etc\logback.xml``). There are multiple ways to
            use different logback configurations, for instance:

         .. container:: ulist

            -  Maintain multiple configurations in ``etc``, for instance
               a ``logback-debug.xml`` for deep debugging and a
               ``logback-production.xml`` for APEX in production mode,
               then copy the required configuration file to the used
               ``logback.xml`` prior starting APEX

            -  Edit the scripts in ``bin`` to use a different logback
               configuration file (only recommended if you are familiar
               with editing bash scripts or windows batch files)

Standard Logging Configuration
------------------------------

         .. container:: paragraph

            The standard logging configuration defines a context *APEX*,
            which is used in the standard output pattern. The location
            for log files is defined in the property ``logDir`` and set
            to ``/var/log/onap/policy/apex-pdp``. The standard status
            listener is set to *NOP* and the overall logback
            configuration is set to no debug.

         .. container:: listingblock

            .. container:: content

               .. code::
                 :number-lines:

                 <configuration debug="false">
                   <statusListener class="ch.qos.logback.core.status.NopStatusListener" />

                    <contextName>Apex</contextName>
                    <property name="logDir" value="/var/log/onap/policy/apex-pdp/" />

                   ...appenders
                   ...loggers
                 </configuration>

.. container:: paragraph

   The first appender defined is called ``STDOUT`` for logs to standard
   out.

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
            <Pattern>%d %contextName [%t] %level %logger{36} - %msg%n</Pattern>
          </encoder>
        </appender>

.. container:: paragraph

   The root level logger then is set to the level *info* using the
   standard out appender.

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        <root level="info">
          <appender-ref ref="STDOUT" />
        </root>

.. container:: paragraph

   The second appender is called ``FILE``. It writes logs to a file
   ``apex.log``.

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        <appender name="FILE" class="ch.qos.logback.core.FileAppender">
          <file>${logDir}/apex.log</file>
          <encoder>
            <pattern>%d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %n %ex{full}</pattern>
          </encoder>
        </appender>

.. container:: paragraph

   The third appender is called ``CTXT_FILE``. It writes logs to a file
   ``apex_ctxt.log``.

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        <appender name="CTXT_FILE" class="ch.qos.logback.core.FileAppender">
          <file>${logDir}/apex_ctxt.log</file>
          <encoder>
            <pattern>%d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %n %ex{full}</pattern>
          </encoder>
        </appender>

.. container:: paragraph

   The last definitions are for specific loggers. The first logger
   captures all standard APEX classes. It is configured for log level
   *info* and uses the standard output and file appenders. The second
   logger captures APEX context classes responsible for context
   monitoring. It is configured for log level *trace* and uses the
   context file appender.

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:


        <logger name="org.onap.policy.apex" level="info" additivity="false">
          <appender-ref ref="STDOUT" />
          <appender-ref ref="FILE" />
        </logger>

        <logger name="org.onap.policy.apex.core.context.monitoring" level="TRACE" additivity="false">
          <appender-ref ref="CTXT_FILE" />
        </logger>

Adding Logback Status and Debug
-------------------------------

   .. container:: paragraph

      To activate logback status messages change the status listener
      from 'NOP' to for instance console.

   .. container:: listingblock

      .. container:: content

         .. code::

            <statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener" />

   .. container:: paragraph

      To activate all logback debugging, for instance to debug a new
      logback configuration, activate the debug attribute in the
      configuration.

   .. container:: listingblock

      .. container:: content

         .. code::

            <configuration debug="true">
            ...
            </configuration>

Logging External Components
---------------------------

   .. container:: paragraph

      Logback can also be configured to log any other, external
      components APEX is using, if they are using the common logging
      framework.

   .. container:: paragraph

      For instance, the context component of APEX is using *Infinispan*
      and one can add a logger for this external component. The
      following example adds a logger for *Infinispan* using the
      standard output appender.

   .. container:: listingblock

      .. container:: content

         .. code::

            <logger name="org.infinispan" level="INFO" additivity="false">
              <appender-ref ref="STDOUT" />
            </logger>

   .. container:: paragraph

      Another example is Apache Zookeeper. The following example adds a
      logger for Zookeeper using the standard outout appender.

   .. container:: listingblock

      .. container:: content

         .. code::

            <logger name="org.apache.zookeeper.ClientCnxn" level="INFO" additivity="false">
              <appender-ref ref="STDOUT" />
            </logger>

Configuring loggers for Policy Logic
------------------------------------

   .. container:: paragraph

      The logging for the logic inside a policy (task logic, task
      selection logic, state finalizer logic) can be configured separate
      from standard logging. The logger for policy logic is
      ``org.onap.policy.apex.executionlogging``. The following example
      defines

   .. container:: ulist

      -  a new appender for standard out using a very simple pattern
         (simply the actual message)

      -  a logger for policy logic to standard out using the new
         appender and the already described file appender.

   .. container:: listingblock

      .. container:: content

         .. code::

            <appender name="POLICY_APPENDER_STDOUT" class="ch.qos.logback.core.ConsoleAppender">
              <encoder>
                <pattern>policy: %msg\n</pattern>
              </encoder>
            </appender>

            <logger name="org.onap.policy.apex.executionlogging" level="info" additivity="false">
              <appender-ref ref="POLICY_APPENDER_STDOUT" />
              <appender-ref ref="FILE" />
            </logger>

   .. container:: paragraph

      It is also possible to use specific logging for parts of policy
      logic. The following example defines a logger for task logic.

   .. container:: listingblock

      .. container:: content

         .. code::

            <logger name="org.onap.policy.apex.executionlogging.TaskExecutionLogging" level="TRACE" additivity="false">
              <appender-ref ref="POLICY_APPENDER_STDOUT" />
            </logger>

Rolling File Appenders
----------------------

   .. container:: paragraph

      Rolling file appenders are a good option for more complex logging
      of a production or complex testing APEX installation. The standard
      logback configuration can be used for these use cases. This
      section gives two examples for the standard logging and for
      context logging.

   .. container:: paragraph

      First the standard logging. The following example defines a
      rolling file appender. The appender rolls over on a daily basis.
      It allows for a file size of 100 MB.

   .. container:: listingblock

      .. container:: content

         .. code::

            <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
              <file>${logDir}/apex.log</file>
              <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
                <!-- rollover daily -->
                <!-- <fileNamePattern>xstream-%d{yyyy-MM-dd}.%i.txt</fileNamePattern> -->
                <fileNamePattern>${logDir}/apex_%d{yyyy-MM-dd}.%i.log.gz
                </fileNamePattern>
                <maxHistory>4</maxHistory>
                <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                  <!-- or whenever the file size reaches 100MB -->
                  <maxFileSize>100MB</maxFileSize>
                </timeBasedFileNamingAndTriggeringPolicy>
              </rollingPolicy>
              <encoder>
                <pattern>
                  %d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %ex{full} %n
                </pattern>
              </encoder>
            </appender>

   .. container:: paragraph

      A very similar configuration can be used for a rolling file
      appender logging APEX context.

   .. container:: listingblock

      .. container:: content

         .. code::

            <appender name="CTXT-FILE"
                  class="ch.qos.logback.core.rolling.RollingFileAppender">
              <file>${logDir}/apex_ctxt.log</file>
              <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
                <fileNamePattern>${logDir}/apex_ctxt_%d{yyyy-MM-dd}.%i.log.gz
                </fileNamePattern>
                <maxHistory>4</maxHistory>
                <timeBasedFileNamingAndTriggeringPolicy
                    class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                  <maxFileSize>100MB</maxFileSize>
                </timeBasedFileNamingAndTriggeringPolicy>
              </rollingPolicy>
              <encoder>
                <pattern>
                  %d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %ex{full} %n
                </pattern>
              </encoder>
            </appender>

Example Configuration for Logging Logic
---------------------------------------

   .. container:: paragraph

      The following example shows a configuration that logs policy logic
      to standard out and a file (*info*). All other APEX components are
      logging to a file (*debug*).. This configuration an be used in a
      pre-production phase with the APEX engine still running in a
      separate terminal to monitor policy execution. This logback
      configuration is in the APEX installation as
      ``etc/logback-logic.xml``.

   .. container:: listingblock

      .. container:: content

         .. code::

            <configuration debug="false">
                <statusListener class="ch.qos.logback.core.status.NopStatusListener" />

                <contextName>Apex</contextName>
                <property name="logDir" value="/var/log/onap/policy/apex-pdp/" />

                <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
                    <encoder>
                        <Pattern>%d %contextName [%t] %level %logger{36} - %msg%n</Pattern>
                    </encoder>
                </appender>

                <appender name="FILE" class="ch.qos.logback.core.FileAppender">
                    <file>${logDir}/apex.log</file>
                    <encoder>
                        <pattern>
                            %d %-5relative [procId=${processId}] [%thread] %-5level%logger{26} - %msg %n %ex{full}
                        </pattern>
                    </encoder>
                </appender>

                <appender name="POLICY_APPENDER_STDOUT" class="ch.qos.logback.core.ConsoleAppender">
                    <encoder>
                        <pattern>policy: %msg\n</pattern>
                    </encoder>
                </appender>

                <root level="error">
                    <appender-ref ref="STDOUT" />
                </root>

                <logger name="org.onap.policy.apex" level="debug" additivity="false">
                    <appender-ref ref="FILE" />
                </logger>

                <logger name="org.onap.policy.apex.executionlogging" level="info" additivity="false">
                    <appender-ref ref="POLICY_APPENDER_STDOUT" />
                    <appender-ref ref="FILE" />
                </logger>
            </configuration>

Example Configuration for a Production Server
---------------------------------------------

   .. container:: paragraph

      The following example shows a configuration that logs all APEX
      components, including policy logic, to a file (*debug*). This
      configuration an be used in a production phase with the APEX
      engine being executed as a service on a system without console
      output. This logback configuration is in the APEX installation as
      ``logback-server.xml``

   .. container:: listingblock

      .. container:: content

         .. code::

            <configuration debug="false">
                <statusListener class="ch.qos.logback.core.status.NopStatusListener" />

                <contextName>Apex</contextName>
                <property name="logDir" value="/var/log/onap/policy/apex-pdp/" />

                <appender name="FILE" class="ch.qos.logback.core.FileAppender">
                    <file>${logDir}/apex.log</file>
                    <encoder>
                        <pattern>
                            %d %-5relative [procId=${processId}] [%thread] %-5level%logger{26} - %msg %n %ex{full}
                        </pattern>
                    </encoder>
                </appender>

                <root level="debug">
                    <appender-ref ref="FILE" />
                </root>

                <logger name="org.onap.policy.apex.executionlogging" level="debug" additivity="false">
                    <appender-ref ref="FILE" />
                </logger>
            </configuration>

Unsupported Features
^^^^^^^^^^^^^^^^^^^^

         .. container:: paragraph

            This section documents some legacy and unsupported features
            in apex-pdp. The documentation here has not been updated for
            recent versions of apex-pdp. For example, the apex-pdp models
            specified in this example should now be in TOSCA format.

Building a System with Websocket Backend
----------------------------------------

Websockets
##########

         .. container:: paragraph

            Websocket is a protocol to run sockets of HTTP. Since it in
            essence a socket, the connection is realized between a
            server (waiting for connections) and a client (connecting to
            a server). Server/client separation is only important for
            connection establishment, once connected, everyone can
            send/receive on the same socket (as any standard socket
            would allow).

         .. container:: paragraph

            Standard Websocket implementations are simple, no
            publish/subscribe and no special event handling. Most
            servers simply send all incoming messages to all
            connections. There is a PubSub definition on top of
            Websocket called `WAMP <http://wamp-proto.org/>`__. APEX
            does not support WAMP at the moment.

Websocket in Java
#################

         .. container:: paragraph

            In Java, `JSR
            356 <http://www.oracle.com/technetwork/articles/java/jsr356-1937161.html>`__
            defines the standard Websocket API. This JSR is part of Jave
            EE 7 standard. For Java SE, several implementations exist in
            open source. Since Websockets are a stable standard and
            simple, most implementations are stable and ready to use. A
            lot of products support Websockets, like Spring, JBoss,
            Netty, … there are also Kafka extensions for Websockets.

Websocket Example Code for Websocket clients (FOSS)
###################################################

         .. container:: paragraph

            There are a lot of implementations and examples available on
            Github for Websocket clients. If one is using Java EE 7,
            then one can also use the native Websocket implementation.
            Good examples for clients using simply Java SE are here:

         .. container:: ulist

            -  `Websocket
               implementation <https://github.com/TooTallNate/Java-WebSocket>`__

            -  `Websocket sending client example, using
               AWT <https://github.com/TooTallNate/Java-WebSocket/blob/master/src/main/example/ChatClient.java>`__

            -  `Websocket receiving client example (simple echo
               client) <https://github.com/TooTallNate/Java-WebSocket/blob/master/src/main/example/ExampleClient.java>`__

         .. container:: paragraph

            For Java EE, the native Websocket API is explained here:

         .. container:: ulist

            -  `Oracle
               docs <http://www.oracle.com/technetwork/articles/java/jsr356-1937161.html>`__

            -  link: `An
               example <http://www.programmingforliving.com/2013/08/jsr-356-java-api-for-websocket-client-api.html>`__

BCP: Websocket Configuration
############################

         .. container:: paragraph

            The probably best is to configure APEX for Websocket servers
            for input (ingress, consume) and output (egress, produce)
            interfaces. This means that APEX will start Websocket
            servers on named ports and wait for clients to connect.
            Advantage: once APEX is running all connectivity
            infrastructure is running as well. Consequence: if APEX is
            not running, everyone else is in the dark, too.

         .. container:: paragraph

            The best protocol to be used is JSON string. Each event on
            any interface is then a string with a JSON encoding. JSON
            string is a little bit slower than byte code, but we doubt
            that this will be noticeable. A further advantage of JSON
            strings over Websockets with APEX starting the servers: it
            is very easy to connect web browsers to such a system.
            Simple connect the web browser to the APEX sockets and
            send/read JSON strings.

         .. container:: paragraph

            Once APEX is started you simply connect Websocket clients to
            it, and send/receive event. When APEX is terminated, the
            Websocket servers go down, and the clients will be
            disconnected. APEX does not (yet) support auto-client
            reconnect nor WAMP, so clients might need to be restarted or
            reconnected manually after an APEX boot.

Demo with VPN Policy Model
##########################

         .. container:: paragraph

            We assume that you have an APEX installation using the full
            package, i.e. APEX with all examples, of version ``0.5.6``
            or higher. We will use the VPN policy from the APEX examples
            here.

         .. container:: paragraph

            Now, have the following ready to start the demo:

         .. container:: ulist

            -  3 terminals on the host where APEX is running (we need 1
               for APEX and 1 for each client)

            -  the events in the file
               ``$APEX_HOME/examples/events/VPN/SetupEvents.json`` open
               in an editor (we need to send those events to APEX)

            -  the events in the file
               ``$APEX_HOME/examples/events/VPN/Link09Events.json`` open
               in an editor (we need to send those events to APEX)

A Websocket Configuration for the VPN Domain
********************************************

            .. container:: paragraph

               Create a new APEX configuration using the VPN policy
               model and configuring APEX as discussed above for
               Websockets. Copy the following configuration into
               ``$APEX_HOME/examples/config/VPN/Ws2WsServerAvroContextJsonEvent.json``
               (for Windows use
               ``%APEX_HOME%\examples\config\VPN\Ws2WsServerAvroContextJsonEvent.json``):

            .. container:: listingblock

               .. container:: content

                  .. code::
                    :number-lines:

                    {
                      "engineServiceParameters" : {
                        "name"          : "VPNApexEngine",
                        "version"        : "0.0.1",
                        "id"             :  45,
                        "instanceCount"  : 1,
                        "deploymentPort" : 12345,
                        "policyModelFileName" : "examples/models/VPN/VPNPolicyModelAvro.json",
                        "engineParameters"    : {
                          "executorParameters" : {
                            "MVEL" : {
                              "parameterClassName" : "org.onap.policy.apex.plugins.executor.mvel.MVELExecutorParameters"
                            }
                          },
                          "contextParameters" : {
                            "parameterClassName" : "org.onap.policy.apex.context.parameters.ContextParameters",
                            "schemaParameters":{
                              "Avro":{
                                "parameterClassName" : "org.onap.policy.apex.plugins.context.schema.avro.AvroSchemaHelperParameters"
                              }
                            }
                          }
                        }
                      },
                      "producerCarrierTechnologyParameters" : {
                        "carrierTechnology" : "WEBSOCKET",
                        "parameterClassName" : "org.onap.policy.apex.plugins.event.carrier.websocket.WEBSOCKETCarrierTechnologyParameters",
                        "parameters" : {
                          "wsClient" : false,
                          "port"     : 42452
                        }
                      },
                      "producerEventProtocolParameters" : {
                        "eventProtocol" : "JSON"
                      },
                      "consumerCarrierTechnologyParameters" : {
                        "carrierTechnology" : "WEBSOCKET",
                        "parameterClassName" : "org.onap.policy.apex.plugins.event.carrier.websocket.WEBSOCKETCarrierTechnologyParameters",
                        "parameters" : {
                         "wsClient" : false,
                          "port"     : 42450
                        }
                      },
                      "consumerEventProtocolParameters" : {
                        "eventProtocol" : "JSON"
                      }
                    }

Start APEX Engine
*****************

   .. container:: paragraph

      In a new terminal, start APEX with the new configuration for
      Websocket-Server ingress/egress:

   .. container:: listingblock

      .. container:: content

         .. code::
            :number-lines:

            #: $APEX_HOME/bin/apexApps.sh engine -c $APEX_HOME/examples/config/VPN/Ws2WsServerAvroContextJsonEvent.json

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        #: %APEX_HOME%\bin\apexApps.bat engine -c %APEX_HOME%\examples\config\VPN\Ws2WsServerAvroContextJsonEvent.json

.. container:: paragraph

   Wait for APEX to start, it takes a while to create all Websocket
   servers (about 8 seconds on a standard laptop without cached
   binaries). depending on your log messages, you will see no (some, a
   lot) log messages. If APEX starts correctly, the last few messages
   you should see are:

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

         2017-07-28 13:17:20,834 Apex [main] INFO c.e.a.s.engine.runtime.EngineService - engine model VPNPolicyModelAvro:0.0.1 added to the engine-AxArtifactKey:(name=VPNApexEngine-0,version=0.0.1)
         2017-07-28 13:17:21,057 Apex [Apex-apex-engine-service-0:0] INFO c.e.a.s.engine.runtime.EngineService - Engine AxArtifactKey:(name=VPNApexEngine-0,version=0.0.1) processing ...
         2017-07-28 13:17:21,296 Apex [main] INFO c.e.a.s.e.r.impl.EngineServiceImpl - Added the action listener to the engine
         Started Apex service

.. container:: paragraph

   APEX is running in the new terminal and will produce output when the
   policy is triggered/executed.

Run the Websocket Echo Client
*****************************

   .. container:: paragraph

      The echo client is included in an APEX full installation. To run
      the client, open a new shell (Unix, Cygwin) or command prompt
      (``cmd`` on Windows). Then use the APEX application launcher to
      start the client.

   .. important::
      APEX engine needs to run first
      The example assumes that an APEX engine configured for *produce* carrier technology Websocket and *JSON* event protocol is executed first.

   +---------------------------------------------------------+-----------------------------------------------------------+
   | Unix, Cygwin                                            | Windows                                                   |
   +=========================================================+===========================================================+
   | .. container::                                          | .. container::                                            |
   |                                                         |                                                           |
   |    .. container:: listingblock                          |    .. container:: listingblock                            |
   |                                                         |                                                           |
   |       .. container:: content                            |       .. container:: content                              |
   |                                                         |                                                           |
   |          .. code::                                      |          .. code::                                        |
   |                                                         |                                                           |
   |             # $APEX_HOME/bin/apexApps.sh ws-echo [args] |             > %APEX_HOME%\bin\apexApps.bat ws-echo [args] |
   +---------------------------------------------------------+-----------------------------------------------------------+

   .. container:: paragraph

      Use the following command line arguments for server and port of
      the Websocket server. The port should be the same as configured in
      the APEX engine. The server host should be the host on which the
      APEX engine is running

   .. container:: ulist

      -  ``-p`` defines the Websocket port to connect to (defaults to
         ``8887``)

      -  ``-s`` defines the host on which a Websocket server is running
         (defaults to ``localhost``)

   .. container:: paragraph

      Let’s assume that there is an APEX engine running, configured for
      produce Websocket carrier technology, as server, for port 42452,
      with produce event protocol JSON,. If we start the console client
      on the same host, we can omit the ``-s`` options. We start the
      console client as:

   .. container:: listingblock

      .. container:: content

         .. code::

            # $APEX_HOME/bin/apexApps.sh ws-echo -p 42452 (1)
            > %APEX_HOME%\bin\apexApps.bat ws-echo -p 42452 (2)

   .. container:: colist arabic

      +-------+--------------------------------+
      | **1** | Start client on Unix or Cygwin |
      +-------+--------------------------------+
      | **2** | Start client on Windows        |
      +-------+--------------------------------+

   .. container:: paragraph

      Once started successfully, the client will produce the following
      messages (assuming we used ``-p 42452`` and an APEX engine is
      running on ``localhost`` with the same port:

   .. container:: listingblock

      .. container:: content

         .. code::

            ws-simple-echo: starting simple event echo
             --> server: localhost
             --> port: 42452

            Once started, the application will simply print out all received events to standard out.
            Each received event will be prefixed by '---' and suffixed by '===='


            ws-simple-echo: opened connection to APEX (Web Socket Protocol Handshake)

Run the Websocket Console Client
********************************

   .. container:: paragraph

      The console client is included in an APEX full installation. To
      run the client, open a new shell (Unix, Cygwin) or command prompt
      (``cmd`` on Windows). Then use the APEX application launcher to
      start the client.

   .. important::
      APEX engine needs to run first
      The example assumes that an APEX engine configured for *consume* carrier technology Websocket and *JSON* event
      protocol is executed first.

   +------------------------------------------------------------+--------------------------------------------------------------+
   | Unix, Cygwin                                               | Windows                                                      |
   +============================================================+==============================================================+
   | .. container::                                             | .. container::                                               |
   |                                                            |                                                              |
   |    .. container:: listingblock                             |    .. container:: listingblock                               |
   |                                                            |                                                              |
   |       .. container:: content                               |       .. container:: content                                 |
   |                                                            |                                                              |
   |          .. code::                                         |          .. code::                                           |
   |                                                            |                                                              |
   |             # $APEX_HOME/bin/apexApps.sh ws-console [args] |             > %APEX_HOME%\bin\apexApps.bat ws-console [args] |
   +------------------------------------------------------------+--------------------------------------------------------------+

   .. container:: paragraph

      Use the following command line arguments for server and port of
      the Websocket server. The port should be the same as configured in
      the APEX engine. The server host should be the host on which the
      APEX engine is running

   .. container:: ulist

      -  ``-p`` defines the Websocket port to connect to (defaults to
         ``8887``)

      -  ``-s`` defines the host on which a Websocket server is running
         (defaults to ``localhost``)

   .. container:: paragraph

      Let’s assume that there is an APEX engine running, configured for
      consume Websocket carrier technology, as server, for port 42450,
      with consume event protocol JSON,. If we start the console client
      on the same host, we can omit the ``-s`` options. We start the
      console client as:

   .. container:: listingblock

      .. container:: content

         .. code::

            # $APEX_HOME/bin/apexApps.sh ws-console -p 42450 (1)
            > %APEX_HOME%\bin\apexApps.sh ws-console -p 42450 (2)

   .. container:: colist arabic

      +-------+--------------------------------+
      | **1** | Start client on Unix or Cygwin |
      +-------+--------------------------------+
      | **2** | Start client on Windows        |
      +-------+--------------------------------+

   .. container:: paragraph

      Once started successfully, the client will produce the following
      messages (assuming we used ``-p 42450`` and an APEX engine is
      running on ``localhost`` with the same port:

   .. container:: listingblock

      .. container:: content

         .. code::

            ws-simple-console: starting simple event console
             --> server: localhost
             --> port: 42450

             - terminate the application typing 'exit<enter>' or using 'CTRL+C'
             - events are created by a non-blank starting line and terminated by a blank line


            ws-simple-console: opened connection to APEX (Web Socket Protocol Handshake)

Send Events
***********

   .. container:: paragraph

      Now you have the full system up and running:

   .. container:: ulist

      -  Terminal 1: APEX ready and loaded

      -  Terminal 2: an echo client, printing received messages produced
         by the VPN policy

      -  Terminal 2: a console client, waiting for input on the console
         (standard in) and sending text to APEX

   .. container:: paragraph

      We started the engine with the VPN policy example. So all the
      events we are using now are located in files in the following
      example directory:

   .. container:: listingblock

      .. container:: content

         .. code::
           :number-lines:

           #: $APEX_HOME/examples/events/VPN
           > %APEX_HOME%\examples\events\VPN

.. container:: paragraph

   To sends events, simply copy the content of the event files into
   Terminal 3 (the console client). It will read multi-line JSON text
   and send the events. So copy the content of ``SetupEvents.json`` into
   the client. APEX will trigger a policy and produce some output, the
   echo client will also print some events created in the policy. In
   Terminal 1 (APEX) you’ll see some status messages from the policy as:

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        {Link=L09, LinkUp=true}
        L09     true
        outFields: {Link=L09, LinkUp=true}
        {Link=L10, LinkUp=true}
        L09     true
        L10     true
        outFields: {Link=L10, LinkUp=true}
        {CustomerName=C, LinkList=L09 L10, SlaDT=300, YtdDT=300}
        *** Customers ***
        C       300     300     [L09, L10]
        outFields: {CustomerName=C, LinkList=L09 L10, SlaDT=300, YtdDT=300}
        {CustomerName=A, LinkList=L09 L10, SlaDT=300, YtdDT=50}
        *** Customers ***
        A       300     50      [L09, L10]
        C       300     300     [L09, L10]
        outFields: {CustomerName=A, LinkList=L09 L10, SlaDT=300, YtdDT=50}
        {CustomerName=D, LinkList=L09 L10, SlaDT=300, YtdDT=400}
        *** Customers ***
        A       300     50      [L09, L10]
        C       300     300     [L09, L10]
        D       300     400     [L09, L10]
        outFields: {CustomerName=D, LinkList=L09 L10, SlaDT=300, YtdDT=400}
        {CustomerName=B, LinkList=L09 L10, SlaDT=300, YtdDT=299}
        *** Customers ***
        A       300     50      [L09, L10]
        B       300     299     [L09, L10]
        C       300     300     [L09, L10]
        D       300     400     [L09, L10]
        outFields: {CustomerName=B, LinkList=L09 L10, SlaDT=300, YtdDT=299}

.. container:: paragraph

   In Terminal 2 (echo-client) you see the received events, the last two
   should look like:

.. container:: listingblock

   .. container:: content

      .. code::
        :number-lines:

        ws-simple-echo: received
        ---------------------------------
        {
          "name": "VPNCustomerCtxtActEvent",
          "version": "0.0.1",
          "nameSpace": "org.onap.policy.apex.domains.vpn.events",
          "source": "Source",
          "target": "Target",
          "CustomerName": "C",
          "LinkList": "L09 L10",
          "SlaDT": 300,
          "YtdDT": 300
        }
        =================================

        ws-simple-echo: received
        ---------------------------------
        {
          "name": "VPNCustomerCtxtActEvent",
          "version": "0.0.1",
          "nameSpace": "org.onap.policy.apex.domains.vpn.events",
          "source": "Source",
          "target": "Target",
          "CustomerName": "D",
          "LinkList": "L09 L10",
          "SlaDT": 300,
          "YtdDT": 400
        }
        =================================

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   Congratulations, you have triggered a policy in APEX using
   Websockets, the policy did run through, created events, picked up by
   the echo-client.

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   Now you can send the Link 09 and Link 10 events, they will trigger
   the actual VPN policy and some calculations are made. Let’s take the
   Link 09 events from ``Link09Events.json``, copy them all into
   Terminal 3 (the console). APEX will run the policy (with some status
   output), and the echo client will receive and print events.

.. container:: paragraph

   To terminate the applications, simply press ``CTRL+C`` in Terminal 1
   (APEX). This will also terminate the echo-client in Terminal 2. Then
   type ``exit<enter>`` in Terminal 3 (or ``CTRL+C``) to terminate the
   console-client.

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   :name: footer

   .. container::
      :name: footer-text