Collect logs from a specified container

[brianredbeard]

As we deploy more of our components in containers we will need a method for collecting logs from a known path inside of a container. In the case of some products this can be handled through inspecting a container, finding it's "logs" volume, and grabbing all of that data.

[jonboulle]

@brianredbeard this sounds a little nebulous - can you be more specific about what you'd like implemented now?

[brianredbeard]

This is a generic version of #13

[tschuy]

This seems like a useful feature to have still.

Currently, our "docker support" is to copy in a bunch of files located in/var/lib/docker.

Looking through https://godoc.org/github.com/docker/engine-api, I don't see an easy way to access files. It might simply be best to shell out to docker inspect.

thoughts?