When pulling an image using Docker 1.8, it seems the output
JSON stream has an empty dict at the very end. This causes
ansible to fail when pulling an image, as it's expecting a
status message in that dict which it uses to determine whether
it had to download the image or not. As a bit of an ugly hack
for that which remains backward compatible, try the last item
in the stream, and if it's an empty dict, take the last-but-one
item instead.
The strip() is needed as the exact value appears to be '{}/r/n';
we could just match that, but it seems like the kind of thing
where maybe it'd happen to just be '{}/n' or '{}' or something
in some cases, so let's just use strip() in case.
A recent change [1] in docker between v1.8.2 and v1.8.3 changed what
is returned in the json when inspecting an image. Five variables which
could have been expected before will now be omited when empty. Only
one of those variables is being addressed in the docker, ExposedPorts.
Unfortunately there was also no API version change on this so this
can't be easily corrected with pinning the API to the older version.
This does a get() which will return None if the variable is not in the
dict formed from the json that was returned. Everything else works the
same way.
[1] 9098628b29
this to determine the location of the Memory value depending on the version used.
In v1.18 and earlier it was ['Config']['Memory'], but in v1.19 it
changed to ['HostConfig']['Memory'].
This is mlosev's patch (from #1208), rebased against devel as of
2790af2. It resolves#1707, which was caused by an API incompatibility
between the docker module and server API version 1.19.
There was a catch-all `except` statement in `create_containers`:
try:
containers = do_create(count, params)
except:
self.pull_image()
containers = do_create(count, params)
This would mask a variety of errors that should be exposed, including
API compatability errors (as in #1707) and common Python exceptions (KeyError, ValueError, etc) that could result from errors in the code.
This change makes the `except` statement more specific, and only attempts to pull the image and start a container if the original create attempt failed due to a 404 error from the docker API.
