The tripleo-ci zuul reproducer fails to stop zuul services (docker_service) due to docker-py

[Marios Andreou]

Running the zuul based reproducer on an rdo cloud vm (using centos - 3.10.0-957.21.3.el7.x86_64 CentOS Linux release 7.6.1810) it fails with trace like:

    ./reproducer-zuul-based-quickstart.sh --workspace ~/WORKSPACE/ -ug marios -rg marios
    ...
    TASK [ansible-role-tripleo-ci-reproducer : Stop up zuul and friends] *************************
    task path: /home/reprozuul/WORKSPACE/roles/ansible-role-tripleo-ci-reproducer/tasks/start.yaml:10
    fatal: [localhost]: FAILED! => {"changed": false, "msg": "Failed to import docker or docker-py - cannot import name __version__. Try `pip install docker` or `pip install docker-py` (Python 2.6)"}

The failing task is there [1] - doing some digging I found that [2]. I _tried_ the suggested pip install docker-py but got the same [3]

[1] https://github.com/rdo-infra/ansible-role-tripleo-ci-reproducer/blob/fbafd6cd6f4a2ac7c4250aa9c244ae775677c004/tasks/start.yaml#L11
[2] https://docs.ansible.com/ansible/latest/modules/docker_compose_module.html#requirements
[3][reprozuul@repro ~]$ pip show docker ==> Version: 3.6.0
   [reprozuul@repro ~]$ pip show docker-py ==> Version: 1.10.6

[Marios Andreou (marios-b)]

ftr i couldn't get this to work on the centos vm... tried all the combinations of docker/docker-py sudo vs --user install but same result.

I tried a different vm and with the rdo fedora-cloud-base-28 image i didn't hit that problem