f28 standalon fails at container prep

[Quique Llorente]

After activating container preparation for standalone f28 is broken using upstream nodepool images
http://logs.openstack.org/56/618056/26/check/tripleo-ci-fedora-28-standalone/28c2db5/logs/undercloud/home/zuul/standalone_deploy.log.txt.gz#_2018-12-12_09_02_10

import pkg_resources", "ModuleNotFoundError: No module named 'pkg_resources'"]

The script /usr/bin/tripleo-container-image-prepare has the shebag "/usr/bin/pyhthon3 -s" and t he "-s" modify means don't add user site directory to sys.path, those f28 images has setuptool installed with pip, so it does not work with the "-s" modifier.

Possible solutions:

- Remove exclusion from dnf.conf so we can install python3-setuptools
- Remove "-s" modifier from the shebag.

Code installing setuptools on images: http://git.openstack.org/cgit/openstack/diskimage-builder/tree/diskimage_builder/elements/pip-and-virtualenv/install.d/pip-and-virtualenv-source-install/04-install-pip#n145

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/625513
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=032e0b1f08a5ed4a3cd1f46996117e838f365cc8
Submitter: Zuul
Branch: master

commit 032e0b1f08a5ed4a3cd1f46996117e838f365cc8
Author: Quique Llorente <email address hidden>
Date: Mon Dec 17 09:41:00 2018 +0100

    Fix ansible-playbook call to python3

    After activating f28 and tripleo prep containers, there are some parts
    that need to be adapted to python3, one example is this, the
    ansible-playbook command for python3 at fedora is ansible-playbook-3.

    Related-Bug: #1808118

    Change-Id: Ideefea9a83ebcfdddbba94f2d44ec7229edf64cd