This docker image is built to get a lightweight rabbitmq cluster without any external dependencies. It is designed to work in docker swarm mode.
Once the rabbitmq-server is up and running the join.sh script will try to join this server instance to a reachable peer. Available peers are determined via nslookup to tasks.<SERVICE_NAME>. If no peer is available but this container is matches SLOT == MASTER_SLOT the rabbitmq app will be just started and no further joining arithmetic will be executed on this container.