Harden matching running containers by "command" in the Docker module
Harden matching running containers by "command" in the Docker module

Before this patch:

  - Command was matched if 'Command' field of docker-py
    representation of Docker container ends with 'command' passed
    to Ansible docker module by user.
  - That can give false positives and false negatives.
  - For example:
      a) If 'command' was set up with more than one spaces,
         like 'command=sleep  123', it would be never matched again
         with a container(s) launched by this task.
         Because after launching, command would be normalized and
         appear, in docker-py API call, just as 'sleep 123' - with one
         space. This is false negative case.
      b) If 'entrypoint + command = command', for example
         'sleep + 123 = sleep 123', module would give false positive
         match.

This patch fixes it, by making matching more explicit - against
'Config'->Cmd' field of 'docker inspect' output, provided by docker-py
API and with proper normalization of user input by splitting it to
tokens with 'shlex.split()'.

thaim/ansible,thaim/ansible