Build Fedora Atomic images using DIB

Registered by Yolanda Robla

Currently to test and deploy Magnum, we rely on downloading a Fedora Atomic image pre-built with docker, kubernetes, flannel, etcd. The fact of relying on the download of an external image on tests is adding an extra overhead, and is a clear single point of failure.

From discussion in #openstack-infra and #openstack-containers channel, the alternative is to build the Fedora Atomic image using DIB regularl, and upload the generated artifact to our mirrors. By this way, the generated image should be smaller and will be contained inside OpenStack network, reducing the point of failure.
The build process for the Fedora Atomic image will use diskimagebuilder. Several steps are needed:
- using a Fedora minimal image, add elements to diskimage-builder to construct the final Fedora Atomic one. Documentation on how to generate Atomic images is here: http://www.projectatomic.io/blog/2014/08/build-your-own-atomic-centos-or-fedora/
- add extra elements to diskimage-builder for installing Flannel, etcd, docker, Kubernetes as systemd services. The image needs to accommodate the current scripts for kubernetes and swarm.

In terms of diskimage-builder needs:
- add a new element on disk image builder to allow creation of logical volumes [OK]
- investigate how Atomic filesystem is generated, and add the filesystem to that extra volume created [In Process]

The build process will be documented properly so that anyone can create a new image with new versions.

This blueprint is largely inspired on: https://blueprints.launchpad.net/magnum/+spec/ubuntu-image-build , and can share some of the diskimage-builder elements

How Fedora Atomic filesystem is composed
==========================
It relies on 2 logical volumes being added to the fedora image:
- volume group atomicos
- two logical volumes:
  * /dev/atomicos/root -> 2.93G
  * /dev/atomicos/docker-pool -> 2G

Blueprint information

Status:
Complete
Approver:
Adrian Otto
Priority:
Medium
Drafter:
Yolanda Robla
Direction:
Approved
Assignee:
Yolanda Robla
Definition:
Approved
Series goal:
Accepted for newton
Implementation:
Implemented
Milestone target:
None
Started by
hongbin
Completed by
Adrian Otto

Related branches

Sprints

Whiteboard

Gerrit topic: https://review.openstack.org/#q,topic:bp/fedora-atomic-image-build,n,z

Addressed by: https://review.openstack.org/301786
    Add script to install image build dependencies

(?)

Work Items

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