volumes_from: doesn't work with custom container names

[genki]

According to the spec, "volumes_from" should accept the name of a service or container, but it can't find the container if the name is custom container name.
Example of docker-compose.yml here;

dev:
  image: busybox
  container_name: data
  volumes:
    - ./db/mongodb:/data/mongodb
mongo:
  image: mongodb
  volumes_from:
   - data

If I type docker-compose ps then an error raises as follows:

Service "mongo" mounts volumes from "data", which is not the name of a service or container. 

May be the timing of name resolution is too early.

[juliantaylor]

I also hit this issue, worked around it by having the named container in another compose file and starting that first
it would be good if the presence of volumes_from providers is only checked when wanting to run containers. It shouldn't be needed to build images or the mentioned ps command.

[dnephin]

I believe this is what's happening:

volumes_from can be either a service or a container, but if it's a container from another service, it makes no guarantee that the container is created first.

The container option is for when you have an external container that you need to get volumes from. If your container is going to be created by compose you should be using the service name.

The reason this is important is because compose orders things based on the dependency graph. If your volumes_from is not a service name, it can't determine the order correctly (it could, but I don't think it's worth the complexity when using the service name is more correct).

So I think the problem here is just that our documentation could be more explicit about this requirement.

If you change your yml to

volumes_from:
    - dev

it should work.

[dnephin]

it would be good if the presence of volumes_from providers is only checked when wanting to run containers. It shouldn't be needed to build images or the mentioned ps command.

Yes, I think this is a nice-to-have. I'll ticket it as #1973

[genki]

Yes I agree with you. Thank you for clarification ;)

[rudijs]

@dnephin Thanks Daniel.

I just hit this same issue and your response sorted it.

From:

volumes_from:
  - container:app:ro

To:

volumes_from:
  - app:ro