Cannot customize yum configuration

[Martin André]

The install_packages macro now sets yum to fail when a package is missing. This makes a ton of sense for certain use cases, such as building for a different architecture where you could have a broken image with missing packages without you knowing it, but it can also be not so good for other scenario were we don't care that much about a missing (non-essential) package.

We should make this setting configurable.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/474582

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/474582
Committed: https://git.openstack.org/cgit/openstack/kolla/commit/?id=0cba3b2ccdcb556eaf31e520ec97e4e624baa01e
Submitter: Jenkins
Branch: master

commit 0cba3b2ccdcb556eaf31e520ec97e4e624baa01e
Author: Martin André <email address hidden>
Date: Thu Jun 15 15:42:06 2017 +0200

    Permit changing yum configuration in the base image

    This commit allows to configure yum settings via a yum.conf file that
    is shipped in the base image and make it overridable with the
    base_yum_conf jinja2 block.

    Change-Id: I76a84ec008fec5696cadefdbdeb4204a32421c4b
    Closes-Bug: #1698134

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla 5.0.0.0b3 development milestone.