I want to run rabbitmq-server in one docker container and connect to it from another container using celery (http://celeryproject.org/)
I have rabbitmq running using
I think you can't connect to another container directly by design - that would be the responsibility of the host. An example of sharing data between containers using Volumes is given here http://docs.docker.io/en/latest/examples/couchdb_data_volumes/, but I don't think that that is what you're looking for.
I recently found out about https://github.com/toscanini/maestro - that might suit your needs. Let us know if it does :), I haven't tried it myself yet.
Edit. Note that you can read here that native "Container wiring and service discovery" is on the roadmap. I guess 7.0 or 8.0 at the latest.