Docker: docker-py updated to 0.3.0 and broke Ansible's docker module - questions about fixing it

Archives Ansible Developer
1

Hey all!

Ansible’s docker module depends on docker-py (Python bindings for the Docker API), and docker-py just pushed a minor-version update bump that contains some changes that break the docker module in Ansible as it is. I’d be happy to push fixes to support this but before I do, I had a few questions:

  1. Is this something we even want? The changes are pretty trivial, but it’ll be tricky to make it completely transparent which version of docker-py we’re working with, as newer versions of the Docker API return different info about each container than older versions do.
  2. How do we deal with backwards-compatibility between versions? Right now there doesn’t seem to be a really good way to tell what version of docker-py we’re working with, which complicates things (I do have a super-simple PR for docker-py open for that here: https://github.com/dotcloud/docker-py/pull/168).
  3. Is https://github.com/ansible/ansible/pull/5639 going to be reviewed/merged in the near-ish future? If it were, it would be a little easier to base future changes off that PR rather than trying to merge later I’d guess.
    Thanks in advance! Let me know if you have any questions.

Josh

2

So, to better understand the backwards incompatibility, is it due to upgrading the default API version to 1.8 from 1.6?

If so, I think that should be pretty easy to handle, by setting version=“1.6” in the docker.client.Client instantiation.

Ideally however, specifying a newer API would improve things, since there are some “inconsistencies” with the 1.6 API.

Maybe we can create a “map” of what different return keys mean for different docker API versions, which could allow us to map the responses from docker-py to a standard output? This could even enable us to make the API version a configurable attribute for the modules.

3

So, to better understand the backwards incompatibility, is it due to upgrading the default API version to 1.8 from 1.6?

If so, I think that should be pretty easy to handle, by setting version=“1.6” in the docker.client.Client instantiation.

There are (easy-to-fix, so far, but still breaking) incompatibilities in the actual Python bindings as well as changes in returned data from API versions.

Setting version="1.6" could help with getting consistent data returned, but that alone won’t make Ansible’s docker module work with 0.3.0.

4

As docker is reasonably unstable right now, I’m content to require and check for the latest and keep updating things.

I am hoping Docker figures out API compat in the future :slight_smile: