RadioVisServer

The RadioVisServer is an implementation of a RadioVis server in Python. Only the Stomp mode is available.

For scalability, the server is connected to a RabbitMq server. It's possible to run multiples instances of the server (sharing one RabbitMq server), allowing more RadioVis client to be connected.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Prerequisites

• python 2.7
• docker 18.06.1+
• virtualenv 16.0.0+
• docker-compose 1.23.2+

Installing

Preparing the venv

virtualenv --python=$(which python2) venv
source venv/bin/activate

Install the required PIP dependencies:

pip install .

To deactivate the running environment:

deactivate

Running the Server

python server.py

Running the Fallback Server

python fallback.py

Configuration

The configuration is stored inside config.py. You can change it by setting environment variables corresponding to the config parameters.

Here is a list of the options you can configure through environment variables:

• RABBITMQ_HOST: Host of the RabbitMQ server. Defaults to 127.0.0.1.
• RABBITMQ_PORT: Port of the RabbitMQ server. Numeric. Defaults to 5672.
• RABBITMQ_USER: User to use when connection to the RabbitMQ server. Default to guest.
• RABBITMQ_PASSWORD: Password of the chosen user. Defaults to guest.
• RABBITMQ_VHOST: RabbitMQ vhost to use. Defaults to /.
• RABBITMQ_DEBUG: If the connections with the RabbitMQ server should be in debug mode. Can be True | False. Defaults to True.
• RABBITMQ_EXCHANGE: RabbitMQ exchange type that will be used by the vis server. Defaults to amq.fanout.
• MONITORING_ENABLED: Switch to enable/disable the RabbitMQ monitoring plugin. Can be True | False. Defaults to True.
• MONITORING_HOST: Host of the monitoring server for the RabbitMQ server. Defaults to 127.0.0.1.
• MONITORING_PORT: Port of the monitoring server for the RabbitMQ server. Defaults to 5672.
• MONITORING_USER: User to use when connection to the monitoring RabbitMQ server. Default to guest.
• MONITORING_PASSWORD: Password of the chosen monitoring user. Defaults to guest.
• MONITORING_VHOST: RabbitMQ monitoring vhost to use. Defaults to /.
• MONITORING_DEBUG: If the connections with the RabbitMQ monitoring server should be in debug mode. Can be True | False. Defaults to True.
• MONITORING_EXCHANGE: monitoring RabbitMQ exchange type. Defaults to monitoring.buffer.
• MONITORING_QUEUE: monitoring RabbitMQ queue. Defaults to radiovis.
• MONITORING_SERVER_ID: RabbitMQ node name. See the RabbitMQ docs.
• STOMP_IP: Accepted hosts for the stomp server. List of host comas separated. Defaults to 0.0.0.0.
• STOMP_PORT: Port where the stomp server will listen to. Numeric. Defaults to 61613.
• RADIODNS_API_URL: RadioDns VIS service url. Scheme: http://<HOST>/<API_SECRET>/action/radiovis/api/<API_SECRET>/. Please refer to the RadioDns manager repository for informations about the API_SECRET parameter.
• MEMCACHED_HOST: Host of the memcached server. Defaults to 127.0.0.1.
• FB_CHANNEL_CACHE: Fallback channels cache time before being considered as stale. In Seconds. Defaults to 60.
• FB_FALLBACK_CHECK: Fallback interval check time. In Seconds. Defaults to 15.
• FB_FALLBACK_TIME: Fallback channel grace time. Time before a channel is considered dead. In Seconds. Defaults to 60.
• FB_LOGS_MAX_AGE: Fallback logs max age before being discarded. In Seconds. Defaults to 86400 (24h).
• FB_LOGS_CLEANUP: Clean Fallaback logs every X seconds, X being this parameter. Defaults to 3600 (1h).

Parts

There is 3 mains parts: The RadioVis server, the fallback server and the test script

RadioVis server

This part takes care of connection to RadioVis clients and forwarding of messages. This can be started using python server.py. Multiple instances can be ran.

It's possible, for debugging, to run the server without a RabbitMQ server. In that case, tests will fail and the fallback server won't work.

Fallback server

The fallback server watch topics, and send the default image and text if there is no activity on a topics for a configurable amount of time. It also takes care of logging all messages (who are forwarded to the PlugIt server). It's connected directly to the RabbitMQ server.

Only one instance of the fallback server should be running at one time. The command to start it is python fallback.py.

Test script

A testing unit is available to tests the RadioVis server and the fallback deamon. It's use node. All tests can simply be run using nosetests. More details are available in the nose documentation. All tests are inside the file test.py.

For testing, a special RadioDns class is used, faking call to the PlugIt API with testing values.

General architecture

Fallback

The fallback process take care of everything related to the watchdog feature and logging. 4 process are spawn.

get_channels_threads

This process retrieve the list of topics from the PlugIt server.

connect_to_rabbitmq

This process ensure we're connected to the RabbitMQ server.

checks_channels

This process check if a topics didn't receive a message for a long time and send the default media if needed.

cleanup_logs

This process takes care of cleaning logs

RabbitMQ

The Rabbitmq process take care of the communication with the RabbitMQ server. It connects to the main exchange, and consume message, broadcasting them to all listening process.

RadioDns

The RadioDns class takes care of communications to the PlugIt API server, allowing call e.g. for authentication, listing of topics, etc.

Stomp

The Stomp class represent a Stomp connection. It takes care of communications with them, allowing login, subscriptions and messages management.

Server

The server takes care of incoming Stomp connections, spawning a stomp server for each new connection and registering them to the RabbitMQ process. It also initializes everything at the startup.

Config

The config is set inside config.py. A base can be found in config.py.dist`. Available options are :

General

LOG_LEVEL

The level of logs message to display.

STOMP_IP

Listening IP for the stomp server

STOMP_PORT

Listening port for the stomp server

API_URL

URL for API of the PlugIt server

CACHE_OPTS

Caching options, see http://beaker.readthedocs.org/en/latest/configuration.html#configuration

RabbitMQ

RABBITMQ_LOOPBACK

If set to true, don't use rabbitmq, but just send messages back! (For debugging)

RABBITMQ_HOST

The RabbitMQ host

RABBITMQ_PORT

The RabbitMQ port

RABBITMQ_USER

The RabbitMQ user

RABBITMQ_PASSWORD

The RabbitMQ password

RABBITMQ_VHOST

The RabbitMQ vhost

RABBITMQ_DEBUG

If we connect to RabbitMQ using debug mode

RABBITMQ_EXCHANGE

The name of the RabbitMQ exchange

Fallback server

FB_CHANNEL_CACHE

Seconds to cache the channel list

FB_QUEUE

Persistant queue

FB_FALLBACK_CHECK

The time when we check for timeouted channels. (Each FB_FALLBACK_CHECK seconds)

FB_FALLBACK_TIME

The time before a channel is dead

FB_IMAGE_LOCATIONS

The base URL for default images (The PlugIt frontend)

FB_LOGS_MAX_AGE

The maximum number of seconds a log entry is kept

FB_LOGS_CLEANUP

When logs are cleaned

Testing

TEST_TOPICS

A list of topics for testing

TEST_ECC

A list of CC=>GCC for testing

TEST_ECC_TOPIC_GCC

A GCC topic for testing

TEST_ECC_TOPIC_CC

The CC equivalent topic for testing

TEST_WATCHDOG_TOPIC

The list of topics for the fallback server

TEST_FB_FALLBACK_CHECK

FB_FALLBACK_CHECK for testing

TEST_FB_FALLBACK_TIME

FB_FALLBACK_TIME for testing

TEST_FB_QUEUE

FB_QUEUE for testing

TEST_FB_LOGS_CLEANUP

FB_LOGS_CLEANUP for testing

TEST_CHANNEL_DEFAULT

Default values for a channel for testing