wcraas_orchestrator

Orchestration examples for the WCraaS platform in docker-compose

A working example that brings the main components of the WCraaS platform together.

Configuring

Some elements of the orchestration can be configured through environment variables.

There are a few configuration points currently (more will follow for added flexibility):

• ENV_COTTONTAIL_MGMT_IFACE
  • The interface on which to expose the rabbitmq management dashboard
  • Leave empty for unmapped
  • if provided must end with :!
• ENV_COTTONTAIL_USER
  • Username for the default rabbitmq user
• ENV_COTTONTAIL_PASS
  • Password for the default rabbitmq user
• ENV_QUEUE_COLLECTION_MAP
  • A JSON object with string keys and string values
  • Used by the wcraas_storage node(s) to determine the target MongoDB collection for an operation based on the source rabbitmq topic

Example configuration

Create a .env file (all /*.env files are ignored in this repository) and declare the above values:

echo 'ENV_COTTONTAIL_MGMT_IFACE=127.0.0.1:' >> .env
echo 'ENV_COTTONTAIL_USER=guest' >> .env
echo 'ENV_COTTONTAIL_PASS=guest' >> .env
echo 'ENV_QUEUE_COLLECTION_MAP={"discovery_raw":"raw","discovery_graph":"graph"}' >> .env

The above configuration will inform docker-compose to:

• Expose the rabbitmq management dashboard on localhost (127.0.0.1); Note the trailing :!
• Set the rabbitmq default user's username to guest
• Set the rabbitmq default user's password to guest
• Subscribe the storage worker to the discovery_raw and discovery_graph topics and insert incoming messages to raw and graph collections accordingly

Bring the stack up

Unfortunately since docker-compose has no built-in way to load an environment file we have to do it pre-pend the following on each docker-compose up command:

env $(cat .env)

So, in order to bring the whole stack up one would do:

env $(cat .env) docker-compose up -d

The suggested approach here however would be to first bring the underlying dependecies up and then the WCraaS layer:

env $(cat .env) docker-compose up -d mongo redis cottontail
# Wait a few seconds (30 ?) for rabbitmq to start accepting connections
env $(cat .env) docker-compose up -d

Finally, enter the control node and execute the wcraas_control command:

docker exec -it wcraas_control sh
wcraas_control <ENTRYPOINT_URL>

The above step will be obsoleted in the future, as the paln is to provide WCraaS control node with an own REST API.