.. 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
^^^^^^^^^^^^
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 `__
- 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 `__
- TAR and GZ to extract from that TAR.GZ
distribution
.. container:: ulist
- Windows for instance
`7Zip `__
- 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 `__ to
connect APEX to a Kafka message bus
- `Hazelcast `__ to use
distributed hash maps for context
- `Infinispan `__ for
distributed context and persistence
- `Docker `__ 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 `__.
.. 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:: |
| |
| .. 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 . |
| 03/09/2018 11:55 .. |
| 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 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 classes |
| 03/09/2018 11:54 dependency-maven-plugin-markers |
| 03/09/2018 11:54 etc |
| 03/09/2018 11:54 examples |
| 03/09/2018 11:55 install_hierarchy |
| 03/09/2018 11:54 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 `__.
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 `__.
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 `__.
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 `__.
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 . |
| 03/09/2018 11:55 .. |
| 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 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 classes |
| 03/09/2018 11:54 dependency-maven-plugin-markers |
| 03/09/2018 11:54 etc |
| 03/09/2018 11:54 examples |
| 03/09/2018 11:55 install_hierarchy |
| 03/09/2018 11:54 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 ```` 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
.. 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
````
.. container:: paragraph
to
.. container:: paragraph
````
.. container:: paragraph
On Windows, it is recommended to change the log directory to:
.. container:: paragraph
````
.. 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.(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
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 `__) 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 `__.
.. container:: paragraph
Installing and using the WAR application requires a web server
that can execute ``war`` web archives. We recommend to use `Apache
Tomcat `__, however other web servers
can be used as well.
.. container:: paragraph
Install Apache Tomcat including the ``Manager App``, see `V9.0
Docs `__
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 `__
or the `Manager App
HOW-TO `__.
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-.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 /bin/bash \
-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)
"policyModelFileName" : "examples/models/VPN/VPNPolicyModelJava.json", (6a)
"policy_type_impl" : {...}, (6b)
"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 `_ |
| | _. |
| | 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 |
+-----------------------------------+-----------------------------------+
| **6a** | the APEX policy model file to |
| | load into the engine on startup |
| | when APEX is running native |
| | policies in standalone mode |
| | (optional) |
+-----------------------------------+-----------------------------------+
| **6b** | 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 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 `__
(a
`tutorial `__).
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 `__.
.. 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 `__
- `Kafka Producer
Class `__
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)
}
}
.. 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 |
+--------+-------------------------------------+
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)
}
}
.. 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 |
+--------+---------------------------------+
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::
...
...
org.onap.policy.apex.plugins.event.carrier.restserver
...
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,
"policyModelFileName" : "examples/models/some-model.json",
"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 for setting
configuration and policy model. The configuration file is
always required. The policy model file is only required if
no model file is specified in the configuration, or if the
specified model file should be over written. The option
``-h`` prints a help screen.
.. container:: listingblock
.. container:: content
.. code::
usage: org.onap.policy.apex.service.engine.main.ApexMain [options...]
options
-c,--config-file the full path to the configuration file to use, the configuration file must be a Json file
containing the Apex configuration parameters
-h,--help outputs the usage of this command
-m,--model-file the full path to the model file to use, if set it overrides the model file set in the
configuration file
-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 name of the apex model properties file to use
-c,--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 name of a file that contains an input model for the editor
-if,--ignore-failures true or false, ignore failures of commands in command files and continue
executing the command file
-l,--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 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 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 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 name of the apex model properties file to use
-ac,--apex-config-file name of the file containing apex configuration details
-c,--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 name of a file that contains an input model for the editor
-if,--ignore-failures true or false, ignore failures of commands in command files and
continue executing the command file
-l,--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 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 name of a file that will contain the output ToscaServiceTemplate
-t,--tosca-template-file name of the input file containing tosca template which needs to be
updated with policy
-wd,--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 to use for the Apex Services REST calls
-t,--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] | [ []]
Options
-d - 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 `` 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 set the input policy model file
-t,--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 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] |
| # $APEX_HOME/bin/apexApps.sh ws-console [args] | > %APEX_HOME%\bin\apexApps.bat ws-console [args] |
+------------------------------------------------------------+--------------------------------------------------------------+
.. container:: paragraph
The arguments are the same for both applications:
.. container:: ulist
- ``-p`` defines the Websocket port to connect to (defaults
to ``8887``)
- ``-s`` defines the host on which a Websocket server is
running (defaults to ``localhost``)
.. container:: paragraph
A discussion on how to use these two applications to build
an APEX system is detailed HowTo-Websockets.
APEX Logging
^^^^^^^^^^^^
Introduction to APEX Logging
----------------------------
.. container:: paragraph
All APEX components make extensive use of logging using the
logging façade `SLF4J `__ with the
backend `Logback `__. Both are used
off-the-shelve, so the standard documentation and
configuration apply to APEX logging. For details on how to
work with logback please see the `logback
manual `__.
.. container:: paragraph
The APEX applications is the logback configuration file
``$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:
Apex
...appenders
...loggers
.. container:: paragraph
The first appender defined is called ``STDOUT`` for logs to standard
out.
.. container:: listingblock
.. container:: content
.. code::
:number-lines:
%d %contextName [%t] %level %logger{36} - %msg%n
.. 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:
.. container:: paragraph
The second appender is called ``FILE``. It writes logs to a file
``apex.log``.
.. container:: listingblock
.. container:: content
.. code::
:number-lines:
${logDir}/apex.log
%d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %n %ex{full}
.. 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:
${logDir}/apex_ctxt.log
%d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %n %ex{full}
.. 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:
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::
.. 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::
...
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::
.. 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::
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::
policy: %msg\n
.. 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::
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::
${logDir}/apex.log
${logDir}/apex_%d{yyyy-MM-dd}.%i.log.gz
4
100MB
%d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %ex{full} %n
.. container:: paragraph
A very similar configuration can be used for a rolling file
appender logging APEX context.
.. container:: listingblock
.. container:: content
.. code::
${logDir}/apex_ctxt.log
${logDir}/apex_ctxt_%d{yyyy-MM-dd}.%i.log.gz
4
100MB
%d %-5relative [procId=${processId}] [%thread] %-5level %logger{26} - %msg %ex{full} %n
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::
Apex
%d %contextName [%t] %level %logger{36} - %msg%n
${logDir}/apex.log
%d %-5relative [procId=${processId}] [%thread] %-5level%logger{26} - %msg %n %ex{full}
policy: %msg\n
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::
Apex
${logDir}/apex.log
%d %-5relative [procId=${processId}] [%thread] %-5level%logger{26} - %msg %n %ex{full}
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 `__. APEX
does not support WAMP at the moment.
Websocket in Java
-----------------
.. container:: paragraph
In Java, `JSR
356 `__
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 `__
- `Websocket sending client example, using
AWT `__
- `Websocket receiving client example (simple echo
client) `__
.. container:: paragraph
For Java EE, the native Websocket API is explained here:
.. container:: ulist
- `Oracle
docs `__
- link: `An
example `__
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' 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
}
=================================
.. container:: paragraph
Congratulations, you have triggered a policy in APEX using
Websockets, the policy did run through, created events, picked up by
the echo-client.
.. container:: paragraph
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`` in Terminal 3 (or ``CTRL+C``) to terminate the
console-client.
.. container::
:name: footer
.. container::
:name: footer-text