Link to an existing container

[marksteve]

Maybe it could work like this:

links:
  - :existing_container_name

[ejholmes]

👍 on this, I'd like to keep several micro services in separate repositories, each with their own fig.yml but share a rabbitmq container. Right now, this doesn't seem possible.

[zazabe]

+1 need to share my postgres with several web app, much more easier in dev mode...

[outrunthewolf]

+1 So is there any workaround for this? I'm keen to get it sorted

[dnephin]

I think #318 is along the same lines as this?

I've got what I think is a working prototype, which I hope to work on more this week or next

[aanand]

In the same way that volumes_from allows both service and container names, maybe links should too, using the same resolution logic.

[koryonik]

+1 would be useful

[lxbrito]

+1 Need to share postgres, redis etc.

[coco98]

+1 Really need this. I like to have separate fig.yml files for different projects, but have some services running in common, so links need to be specified for existing containers.

[tomfotherby]

+1 I have 3 fig.yml files for 3 projects and one thing common between them all is that they all include a memcache container. It would be fantastic if all projects could share the same memcache container.

[stevenjack]

👍 On this, I've also got a number of fig.yaml files in separate projects that's I'd like to share a common container.

[jbalonso]

I have implemented this feature request here: https://github.com/LuminosoInsight/fig/tree/external-links. This uses @marksteve's original format proposal, which addresses a different use case than #318, as I am not in a position where it is completely appropriate to assume that all our containers are launched from fig.

I have not submitted a PR yet, as I need to write tests. Also, my approach feels a little uncomfortably brutal (I originally implemented an external_links feature before I found this issue).