This patch adds image building process for OSH.
Each root folder contains a 'kind' of images to build. Each folder will
have its own parent job, inheriting from a 'openstack-helm-images-base'
job. The folder 'parent job' is used for building distribution
variants (centos_7, ubuntu_xenial, opensuse_15).
Folders containing Dockerfiles (a different Dockerfiles per
distribution) will use the docker building play (docker-build.yml).
Dockerfiles come from openstack-helm-infra repository,
with the following changes:
* The deprecated "MAINTAINER" directive has been replaced with
* If Dockerfiles' default arguments were mismatching the
documentation or Makefiles, they were adapted (see libvirt).
* Relative paths to the openstack-helm-infra repo have been removed.
Each folder is given a convenience build script (build.sh) which
can be used to build a specific image manually.
This script's content gets included in the documentation to avoid
duplications of content.
This patch focuses on each image separately.
Another patch will be added to deal with a repo-wide image building
process, whether for CI purposes, or for developer's purposes,
with the help of a Makefile.
Note: Kubeadm-aio image was not imported in this process due to
circular dependencies: Image building currently requires the
helm charts of openstack-helm-infra.