Add docker_compose module

[ghost]

This adds support for using docker-compose (formerly fig) as a module.
For more information, see here: http://docs.docker.com/compose/

[bcoca]

The exception handling is too generic, errors will depend on
underlying api being clear, which is not always the case, we prefer
more fine grained messages on our side, always adding the message from
the underlying library.

[bcoca]

command is not a pattern we like to follow, we prefer a more imperative 'state', in this case some I would need to know more about some of the options which don't seem to fit

[abadger]

You mean s/imperative/declarative/ right?

[bcoca]

^ what he said.

[ghost]

In this case though, 'state' isn't really accurate. state=scale doesn't make much sense to me. state=up and state=start are two different commands and I think it would lead to confusion.

[abadger]

I noticed that this module lacks the .py extension. In current ansible, the ansible modules are python modules as well so they need to be named like docker_compose.py

[ghost]

To be clear, for error handling the expectation is to catch errors from docker-compose and have an explict message in the module instead of passing up the exceptions message?

[bcoca]

no, normally the APIs give generic messages and are not very helpful to map to the ansible input, we prefer to use exception handling on 'connect/create/destroy' and return a message with the action attempted + the underlying exception.

[gregdek]

closing and reopening to kick travis, since there are a bunch of unrelated failures here

[gregdek]

OK, travis issues are cleared. @SamYaple if you can address @bcoca issues about exception handling and then let us know, we can re-review for inclusion.

[ghost]

I am going to have to abandon this for now. Each new revision of docker-compose is changing key parts of the structure. Almost like it wasn't meant to be a library to be imported ;)

I am going to wait for that structure to stabilize before attempting. If someone else wants to continue the work they can go for it

[gregdek]

Thanks @SamYaple.