path: root/conductor/doc/distribution/README.md

# Python/Linux Distribution Notes

*Updated: 10 Nov 2017 23:30 GMT*

This document exists to help bridge the gap between the Conductor python package and any downstream distribution. The steps outlined herein may be taken into consideration when creating an AT&T SWM package, Ubuntu/Debian package, Chef cookbook, or Ansible playbook.

## Components

Conductor consists of five services that work together:

* **``conductor-api``**: An HTTP REST API
* **``conductor-controller``**: Validation, translation, and status/results
* **``conductor-data``**: Inventory provider and service controller gateway
* **``conductor-solver``**: Processing and solution calculation
* **``conductor-reservation``**: Reserves the suggested solution solved by Solver component.

## Workflow

* Deployment **plans** are created, viewed, and deleted via ``conductor-api`` and its  [REST API](doc/api/README.md).
* Included within each ``conductor-api`` plan request is a [Homing Template](doc/template/README.md).
* Homing Templates describe a set of inventory demands and constraints to be solved against.
* ``conductor-api`` hands off all API requests to ``conductor-controller`` for handling.
* All deployment plans are assigned a unique identifier (UUID-4), which can be used to check for solution status asynchronously. (Conductor does not support callbacks at this time.)
* ``conductor-controller`` ensures templates are well-formed and valid. Errors and remediation are made visible through ``conductor-api``. When running in debug mode, the API will also include a python traceback in the response body, if available.
* ``conductor-controller`` uses ``conductor-data`` to resolve demands against a particular **inventory provider** (e.g., A&AI).
* ``conductor-controller`` translates the template into a format suitable for solving.
* As each template is translated, ``conductor-solver`` begins working on it.
* ``conductor-solver`` uses ``conductor-data`` to resolve constraints against a particular **service controller** (e.g., SDN-C).
* ``conductor-solver`` determines the most suitable inventory to recommend.
* ``conductor-reservation`` attempts to reserve the solved solution in SDN-GC

**NOTE**: There is no Command Line Interface or Python API Library at this time.

## Pre-Flight and Pre-Installation Considerations

### AT&T Application Identifiers and Roles

* App/Tool Name: ECOMP Conductor
* MOTS Application ID: 26213
* MechID: m04308
* ECOMP Feature ID: F13704
* PMT: 461306
* UAM Role Name: Conductor Production Support
* UAM Role id: 0000025248

### Root

Be aware that some commands may require ``sudo``, depending on the account being used to perform the installation.

### Proxy

If line-of-sight to internet-facing repositories is permitted and available, set the following shell environment variables if AT&T proxy services are required:

```bash
$ export http_proxy="http://one.proxy.att.com:8080/"
$ export https_proxy="http://one.proxy.att.com:8080/"
```

### Requirements

Conductor is officially supported on [Ubuntu 14.04 LTS (Trusty Tahr)](http://releases.ubuntu.com/14.04/), though it should also work on newer releases.

Ensure the following Ubuntu packages are present, as they may not be included by default:

* [libffi-dev](http://packages.ubuntu.com/trusty/libffi-dev)
* [postgresql-server-dev-9.3](http://packages.ubuntu.com/trusty/postgresql-server-dev-9.3)
* [python2.7](http://packages.ubuntu.com/trusty/python2.7)

``conductor-api`` may be run as-is for development and test purposes. When used in a production environment, it is recommended that ``conductor-api`` run under a multithreaded httpd service supporting [WSGI](https://www.wikipedia.org/wiki/Web_Server_Gateway_Interface), tuned as appropriate.

Configuration instructions for **apache2 httpd** and **nginx** are included herein. Respective package requirements are:

* [apache2](http://packages.ubuntu.com/trusty/apache2) and [libapache2-mod-wsgi](http://packages.ubuntu.com/trusty/libapache2-mod-wsgi)
* [nginx](http://packages.ubuntu.com/trusty/nginx) and [uwsgi](http://packages.ubuntu.com/trusty/uwsgi)

All Conductor services use AT&T [Music](https://github.com/att/music) for data storage/persistence and/or as a RPC transport mechanism. Consult the [Music Local Installation Guide](https://github.com/att/music/blob/master/README.md) for installation/configuration steps.

### Networking

All conductor services require line-of-sight access to all Music servers/ports.

The ``conductor-api`` service uses TCP port 8091.

### Security

``conductor-api`` is accessed via HTTP. SSL/TLS certificates and AuthN/AuthZ (e.g., AAF) are not supported at this time.

Conductor makes use of plugins that act as gateways to *inventory providers* and *service controllers*. At present, two plugins are supported out-of-the-box: **A&AI** and **SDN-C**, respectively.

A&AI requires two-way SSL/TLS. Certificates must be registered and whitelisted with A&AI. SDN-C uses HTTP Basic Authentication. Consult with each respective service for official information on how to obtain access.

### Storage

For a cloud environment in particular, it may be desirable to use a separate block storage device (e.g., an OpenStack Cinder volume) for logs, configuration, and other data persistence. In this way, it becomes a trivial matter to replace the entire VM if necessary, followed by reinstallation of the app and any supplemental configuration. Take this into consideration when setting various Conductor config options.

### Python Virtual Environments

At present, Conductor installation is only supported at the (upstream) python package level and not the (downstream) Ubuntu distribution or SWM package levels.

To mitigate/eliminate the risk of introducing conflicts with other python applications or Ubuntu/SWM package dependencies, consider installing Conductor in a [python virtual environment](http://docs.python-guide.org/en/latest/dev/virtualenvs/) (or *venv* for short).

Example venv-aware WSGI app configurations, sysvinit scripts, and upstart scripts can be found in the Conductor repository under [examples](/examples/).

### Python Package Dependencies

Conductor is installed using the python ``pip`` command. ``pip`` uses a python project's [requirements manifest](/requirements.txt) to install all python module dependencies.

**NOTE**: When line-of-sight access to a PyPI-compatible package index is not available, advance installation of Conductor's python package dependencies is required *before* installation.

### Other Production Environment Considerations

TBD. ``:)``

Over time, considerations may include services such as:

* AAF
* AppMetrics
* Introscope
* Nagios
* Splunk
* UAM

## Installation and Configuration

**IMPORTANT**: Perform the steps in this section after *optionally* configuring and activating a python virtual environment.

### Installing From a PyPI Repository

In ONAP, the ``conductor`` package can be found on ````.

Installation is via the ``pip`` command. Here is an example ``pip.conf`` file that uses both the internet and intranet-facing PyPI repositories:

```ini
[global]
index = https://pypi.python.org/pypi
index-url = https://pypi.python.org/simple
extra-index-url = 
trusted-host = 
```

Once the configuration is in place, installation is simple:

```bash
$ pip install of-has
```

To upgrade or downgrade, simply re-run ``pip install`` using the appropriate ``pip`` command line options.

**NOTE**: Be sure proxy settings are in place if they're required to access ``pypi.python.org``.

### Installing From Source

Conductor source in ONAP is maintained in https://gerrit.onap.org/r/optf/has.

Clone the git repository, and then install from within the ``conductor`` directory:

```bash
$ git clone https://gerrit.onap.org/r/optf/has
Cloning into 'conductor'...
remote: Counting objects: 2291, done.
remote: Compressing objects:  88% (1918/2179)   
remote: Compressing objects: 100% (2179/2179), done.
remote: Total 2291 (delta 1422), reused 0 (delta 0)
Receiving objects: 100% (2291/2291), 477.59 KiB | 0 bytes/s, done.
Resolving deltas: 100% (1422/1422), done.
$ cd conductor
$ pip install .
```

The latest source can be pulled from ONAP at any time and reinstalled:

```bash
$ git pull
$ pip install .
```

### Verifying Installation

Each of the five Conductor services may be invoked with the ``--help`` option:

```bash
$ conductor-api -- --help
$ conductor-controller --help
$ conductor-data --help
$ conductor-solver --help
$ conductor-reservation --help
```

**NOTE**: The ``conductor-api`` command is deliberate. ``--`` is used as as separator between the arguments used to start the WSGI server and the arguments passed to the WSGI application.

## Post-Flight and Post-Installation Considerations

### User and Group

It's good practice to create an unprivileged account (e.g., a user/group named ``conductor``) and run all Conductor services as that user:

```bash
$ sudo addgroup --system conductor 
$ sudo adduser --system --home /var/lib/conductor --ingroup conductor --no-create-home --shell /bin/false conductor
```

### SSL/TLS Certificates
 
The A&AI Inventory Provider Plugin requiries two-way SSL/TLS. After provisioning a certificate per A&AI guidelines, it will be necessary to securely install the certificate, key, and certificate authority bundle.

When running conductor services as ``conductor:conductor`` (recommended), consider co-locating all of these files under the configuration directory. For example, when using ``/etc/conductor``:

```bash
$ # Certificate files (crt extension, 644 permissions)
$ sudo mkdir /etc/conductor/ssl/certs
$ # Private Certificate Key files (key extension, 640 permissions)
$ sudo mkdir /etc/conductor/ssl/private
$ # Certificate Authority (CA) Bundles (crt extension, 644 permissions)
$ sudo mkdir /etc/conductor/ssl/ca-certificates
$ # Add files to newly created directories, then set ownership
$ sudo chmod -R conductor:conductor /etc/conductor/ssl
```

For a hypothetical domain name ``imacculate.client.research.att.com``, example filenames could be as follows:

```bash
$ find ssl -type f -printf '%M %u:%g %f\n'
-rw-r----- conductor:conductor imacculate.client.research.att.com.key
-rw-r--r-- conductor:conductor Symantec_Class_3_Secure_Server_CA.crt
-rw-r--r-- conductor:conductor imacculate.client.research.att.com.crt
```

When running conductor services as ``root``, consider these existing Ubuntu filesystem locations for SSL/TLS files:

**Certificate** files (``crt`` extension) are typically stored in ``/etc/ssl/certs`` with ``root:root`` ownership and 644 permissions.

**Private Certificate Key** files (``key`` extension) are typically stored in ``/etc/ssl/private`` with ``root:root`` ownership and 640 permissions.

**Certificate Authority (CA) Bundles** (``crt`` extension) are typically stored in ``/usr/share/ca-certificates/conductor`` with ``root:root`` ownership, and 644 permissions. These Bundle files are then symlinked within ``/etc/ssl/certs`` using equivalent filenames, a ``pem`` extension, and ``root:root`` ownership.

**NOTE**: LUKS (Linux Unified Key Setup) is not supported by Conductor at this time.

### Configuration

Configuration files are located in ``etc/conductor`` relative to the python environment Conductor is installed in.

To generate a sample configuration file, change to the directory just above where ``etc/conductor`` is located (e.g., `/` for the default environment, or the virtual environment root directory). Then:

```bash
$ oslo-config-generator --config-file=etc/conductor/conductor-config-generator.conf
```

This will generate ``etc/conductor/conductor.conf.sample``.

Because the configuration directory and files will include credentials, consider removing world permissions:

```bash
$ find etc/conductor -type f -exec chmod 640 {} +
$ find etc/conductor -type d -exec chmod 750 {} +
```

The sample config may then be copied and edited. Be sure to backup any previous ``conductor.conf`` if necessary.

```bash
$ cd etc/conductor
$ cp -p conductor.conf.sample conductor.conf
```

``conductor.conf`` is fully annotated with descriptions of all options. Defaults are included, with all options commented out. Conductor will use defaults even if an option is not present in the file. To change an option, simply uncomment it and edit its value.

With the exception of the ``DEFAULT`` section, it's best to restart the Conductor services after making any config changes. In some cases, only one particular service actually needs to be restarted. When in doubt, however, it's best to restart all of them.

A few options in particular warrant special attention:

```
[DEFAULT]

# If set to true, the logging level will be set to DEBUG instead of the default
# INFO level. (boolean value)
# Note: This option can be changed without restarting.
#debug = false
```

For more verbose logging across all Conductor services, set ``debug`` to true.

```
[aai]
                    
# Base URL for A&AI, up to and not including the version, and without a
# trailing slash. (string value)
#server_url = https://controller:8443/aai

# SSL/TLS certificate file in pem format. This certificate must be registered
# with the A&AI endpoint. (string value)
#certificate_file = certificate.pem

# Private Certificate Key file in pem format. (string value)
#certificate_key_file = certificate_key.pem

# Certificate Authority Bundle file in pem format. Must contain the appropriate
# trust chain for the Certificate file. (string value)
#certificate_authority_bundle_file = certificate_authority_bundle.pem
```

Set ``server_url`` to the A&AI server URL, to but not including the version, omitting any trailing slash. Conductor supports A&AI API v9 at a minimum.

Set the ``certificate`` prefixed keys to the appropriate SSL/TLS-related files.

**IMPORTANT**: The A&AI server may have a mismatched host/domain name and SSL/TLS certificate. In such cases, certificate verification will fail. To mitigate this, ``certificate_authority_bundle_file`` may be set to an empty value. While Conductor normally requires a CA Bundle (otherwise why bother using SSL/TLS), this requirement has been temporarily relaxed so that development and testing may continue.

```
[messaging_server]

# Log debug messages. Default value is False. (boolean value)
#debug = false
```

When the ``DEFAULT`` section's ``debug`` option is ``true``, set this section's ``debug`` option to ``true`` to enable detailed Conductor-side RPC-over-Music debug messages.

Be aware, it is voluminous. "You have been warned." ``:)``

```
[music_api]

# List of hostnames (round-robin access) (list value)
#hostnames = localhost

# Log debug messages. Default value is False. (boolean value)
#debug = false
```

Set ``hostnames`` to match wherever the Music REST API is being hosted (wherever Apache Tomcat and ``MUSIC.war`` are located).

When the ``DEFAULT`` section's ``debug`` option is ``true``, set this section's ``debug`` option to ``true`` to enable detailed Conductor-side MUSIC API debug messages.

The previous comment around the volume of log lines applies even more so here. (Srsly. We're not kidding.)

**IMPORTANT**: Conductor does not presently use Music's atomic consistency features due to concern around lock creation/acquisition. Instead, Conductor uses eventual consistency. For this reason, consistency issues may occur when using Music in a multi-server, High Availability configuration.

```
[sdnc]

# Base URL for SDN-C. (string value)
#server_url = https://controller:8443/restconf

# Basic Authentication Username (string value)
#username = <None>

# Basic Authentication Password (string value)
#password = <None>

```

Set ``server_url`` to the SDN-C server URL, omitting any trailing slash.

Set ``username`` and ``password`` to the appropriate values as directed by SDN-C.

### Running for the First Time

Each Conductor component may be run interactively. In this case, the user does not necessarily matter.

When running interactively, it is suggested to run each command in a separate terminal session and in the following order:

```bash
conductor-data --config-file=/etc/conductor/conductor.conf
conductor-controller --config-file=/etc/conductor/conductor.conf
conductor-solver --config-file=/etc/conductor/conductor.conf
conductor-reservation --config-file=/etc/conductor/conductor.conf
conductor-api --port=8091 -- --config-file=/etc/conductor/conductor.conf
```

Optionally, use an application like [screen](http://packages.ubuntu.com/trusty/screen) to nest all five terminal sessions within one detachable session. (This is also the same package used by [DevStack](https://docs.openstack.org/developer/devstack/).)

To verify that ``conductor-api`` can be reached, browse to ``http://HOST:8091/``, where HOST is the hostname ``conductor-api`` is running on. No AuthN/AuthZ is required at this time. Depending on network considerations, it may be necessary to use a command like ``wget`` instead of a desktop browser.

The response should look similar to:

```json
{
  "versions": {
    "values": [
      {
        "status": "development",
        "updated": "2016-11-01T00:00:00Z",
        "media-types": [
          {
            "base": "application/json",
            "type": "application/vnd.ecomp.homing-v1+json"
          }
        ],
        "id": "v1",
        "links": [
          {
            "href": "http://127.0.0.1:8091/v1",
            "rel": "self"
          },
          {
            "href": "http://conductor.research.att.com/",
            "type": "text/html",
            "rel": "describedby"
          }
        ]
      }
    ]
  }
}
```

### Sample API Calls and Homing Templates

A [Postman](http://getpostman.com/) collection illustrating sample requests is available upon request. The collection will also be added in a future revision.
 
[Sample homing templates](/doc/examples/README.md) are also available.

### Ubuntu Service Scripts

Ubuntu sysvinit (init.d) and upstart (init) scripts are typically installed at the Ubuntu package level. Since there is no such packaging at this time, example scripts have been provided in the repository.

To install, place all Conductor [sysvinit scripts](/examples/distribution/ubuntu/init.d) in ``/etc/init.d``, and all [upstart scripts](/examples/distribution/ubuntu/init) in ``/etc/init``.

Set file permissions:

```bash
$ sudo chmod 644 /etc/init/conductor*
$ sudo chmod 755 /etc/init.d/conductor*
```

If a python virtual environment is being used, edit each ``/etc/init/conductor*`` and ``/etc/init.d/conductor*`` prefixed file so that ``PYTHON_HOME`` is set to the python virtual environment root directory.

Next, enable the scripts:

```bash
$ sudo update-rc.d conductor-api defaults
$ sudo update-rc.d conductor-controller defaults
$ sudo update-rc.d conductor-data defaults
$ sudo update-rc.d conductor-solver defaults
$ sudo update-rc.d conductor-reservation defaults
$ sudo initctl reload-configuration
```

Conductor components may now be started/stopped like any other Ubuntu service, for example:

```bash
$ sudo service conductor-api start
$ sudo service conductor-api status
$ sudo service conductor-api restart
$ sudo service conductor-api stop
```

Conductor service scripts automatically create directories for ``log``, ``lock``, ``run``, ``lib``, and ``log`` files, e.g., ``/var/log/conductor`` and so on.

### Log File Rotation

Sample ``logrotate.d`` configuration files have been provided in the repository.

To install, place all Conductor [logrotate files](/examples/distribution/ubuntu/logrotate.d) in ``/etc/logrotate.d``.

Set file ownership and permissions:

```bash
$ sudo chown root:root /etc/logrotate.d/conductor*
$ sudo chmod 644 /etc/logrotate.d/conductor*
```

``logrotate.d`` automatically recognizes new files at the next log rotation opportunity and does not require restarting.

## Running conductor-api Under apache2 httpd and mod_wsgi

Sample configuration files have been provided in the repository.

These instructions presume a ``conductor`` user exists. See the **Service Scripts** section for details.

First, set up a few directories:

```bash
$ sudo mkdir -p /var/www/conductor
$ sudo mkdir /var/log/apache2/conductor
```

To install, place the Conductor [WSGI application file](/conductor/api/app.wsgi) in ``/var/www/conductor``.

Set the owner/group of both directories/files to ``conductor``:

```bash
$ sudo chown -R conductor:conductor /var/log/apache2/conductor /var/www/conductor
```

Next, place the Conductor [apache2 httpd site config file](/examples/apache2/conductor.conf) in ``/etc/apache2/sites-available``.

Set the owner/group to ``root``:

```bash
$ sudo chown -R root:root /etc/apache2/sites-available/conductor.conf
```

If Conductor was installed in a python virtual environment, append ``python-home=VENV`` to ``WSGIDaemonProcess``, where ``VENV`` is the python virtual environment root directory.

**IMPORTANT**: Before proceeding, disable the ``conductor-api`` sysvinit and upstart services, as the REST API will now be handled by apache2 httpd. Otherwise there will be a port conflict, and you will be sad.

Enable the Conductor site, ensure the configuration syntax is valid, and gracefully restart apache2 httpd. 

```bash
$ sudo a2ensite conductor
$ sudo apachectl -t
Syntax OK
$ sudo apachectl graceful
```

To disable the Conductor site, run ``sudo a2dissite conductor``, then gracefully restart once again. Optionally, re-enable the ``conductor-api`` sysvinit and upstart services.

## Running conductor-api Under nginx and uWSGI

Sample configuration files have been provided in the repository.

These instructions presume a ``conductor`` user exists. See the **Service Scripts** section for details.

To install, place the Conductor [nginx config files](/examples/nginx/) and [WSGI application file](/conductor/api/app.wsgi) in ``/etc/nginx`` (taking care to backup any prior configuration files). It may be desirable to incorporate Conductor's ``nginx.conf`` into the existing config.

Rename ``app.wsgi`` to ``conductor.wsgi``:

```bash
$ cd /etc/nginx
$ sudo mv app.wsgi conductor.wsgi
```

In ``nginx.conf``, set ``CONDUCTOR_API_FQDN`` to the server name.

**IMPORTANT**: Before proceeding, disable the ``conductor-api`` sysvinit and upstart services, as the REST API will now be handled by nginx. Otherwise there will be a port conflict, and you will be sad.

Restart nginx:

```bash
$ sudo service nginx restart
```

Then, run ``conductor-api`` under nginx  using uWSGI:

```bash
$ sudo uwsgi -s /tmp/uwsgi.sock --chmod-socket=777 --wsgi-file /etc/nginx/conductor.wsgi --callable application --set port=8091
```

To use a python virtual environment, add ``--venv VENV`` to the ``uwsgi`` command, where ``VENV`` is the python virtual environment root directory.

## Uninstallation

Activate a virtual environment (venv) first, if necessary, then uninstall with:

```bash
$ pip uninstall ecomp-conductor
```

Remove any previously made configuration file changes, user accounts, Ubuntu/SWM packages, and other settings as needed.

## Bug Reporting and Feedback

... is encouraged. Please raise an issue at: https://jira.onap.org/projects/OPTFRA/summary