We are running a bunch of services in their own containers via Docker, and we connect them using Docker Compose.
Previously we used linking to refer to other hosts, but the problem with that is that if a container is restarted and gets a new IP address then the linked nodes won't know about this and would stop working.
So we went with creating a network and naming our hosts and this works fine. However we have a mock component which we use for testing which replaces two of the other containers. I could configure this via links easily, but I don't know how to do this with networking.
Originally it was like:
mm: extends: file: common-service.yml service: mm-container links: - mock:enet - mock:ff
mm is the container that knows about the containers
ff, and in this compose file used for testing we link them to the
mock container instead.)
I tried adding this instead of the links:
extra_hosts: - "enet:mock" - "ff:mock"
ff are the mocked hostnames) but of course this would add these lines to /etc/hosts as-is, so no hostname resolution takes place.
Is there a solution for this in Docker-land, or do we have to rewrite our mocking tool?