container override file misses packages

[Michele Baldessari]

So Damien and I were hitting an issue where puppet was not installed in the container images when rebuilding. We use tripleo-common/container-images/tripleo_kolla_template_overrides.j2 override which has the following snippet:
...
# This installs the puppet dependency in the base container and includes helper scripts
{% set base_centos_binary_packages_append = ['openstack-tripleo-common-container-base'] %}
{% set nova_scheduler_packages_append = ['openstack-tripleo-common'] %}

# Required for docker-puppet.py to move the generated config to /var/lib/config-data
{% set base_centos_binary_packages_append = ['rsync'] %}
...

If we change the above to:
...
# This installs the puppet dependency in the base container and includes helper scripts
{% set base_centos_binary_packages_append = ['openstack-tripleo-common-container-base', 'rsync'] %}
{% set nova_scheduler_packages_append = ['openstack-tripleo-common'] %}
...

Things are dandy again and both packages get installed (rsync and openstack-tripleo-common-container-base). Previously only rsync would be installed. As if the _append statement did not really append packages but set them.

[Michele Baldessari (michele)]

While the fix above worked for us, I am a bit stumped as to why this is not breaking for more folks. Any rebuild of the kolla base image should break I would think

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/471781

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/471781
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=349e19f66c4535785b2bcf221ab9e008cfa10684
Submitter: Jenkins
Branch: master

commit 349e19f66c4535785b2bcf221ab9e008cfa10684
Author: Michele Baldessari <email address hidden>
Date: Wed Jun 7 15:51:53 2017 +0200

    Do not use multiple overrides with the same name

    Having multiple base_centos_binary_packages_append declarations makes it
    so that only the last one wins. In this case we'd get rsync but no
    puppet and the containers could not create the proper configuration
    files due to missing /usr/bin/puppet.

    Authored-By: Damien Ciabrini <email address hidden>

    Closes-Bug: #1696426
    Change-Id: I16b6bb99a2adf467c34258df2050fcc4f01158f2

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tripleo-common 7.2.0 release.