OpenStack LOCI

OpenStack LOCI is a project designed to quickly build Lightweight OCI compatible images of OpenStack services.

Currently we build and gate images for the following OpenStack projects:

• Cinder
• Glance
• Heat
• Horizon
• Ironic
• Keystone
• Neutron
• Nova

Additionally, we produce a "wheels" image for requirements containing all of the packages listed in upper-constraints.txt.

The instructions below can be used for any OpenStack service currently targeted by LOCI. For simplicity, we will continue to use Keystone as an example.

Keystone Image Layer Info

Building locally

It's really easy to build images locally for the distro of your choice. To build an image you only need to run one of the following commands:

$ docker build https://git.openstack.org/openstack/loci.git --build-arg PROJECT=keystone --tag keystone:ubuntu
$ docker build https://git.openstack.org/openstack/loci.git --build-arg PROJECT=keystone --tag keystone:centos --build-arg FROM=centos:7

If building behind a proxy, remember to use build arguments to pass these through to the build:

$ docker build https://git.openstack.org/openstack/loci.git \
    --build-arg http_proxy=$http_proxy \
    --build-arg https_proxy=$https_proxy \
    --build-arg no_proxy=$no_proxy \
    --build-arg PROJECT=keystone \
    --tag keystone:ubuntu

You can, of course, substitute ubuntu with your distro of choice using the FROM build arg.

For more advanced building you can use docker build arguments to define:

• FROM The base Docker image to build from. Currently supported are ubuntu:xenial and centos:7
• PROJECT The name of the project to install.
• PROJECT_REPO The git repo containing the OpenStack project the container should contain
• PROJECT_REF The git ref, branch, or tag the container should fetch for the project
• UID The uid of the user that will be created (defaults to 42424).
• GID The gid of the group that will be created (default to 42424).
• WHEELS The location of the wheels tarball. This accepts a url to a tarball or a Docker image name in the form of [myregistry/]mydockernamespace/requirements[:ubuntu]
• DISTRO This is a helper variable used for scripts. It would primarily be used in situations where the script would not detect the correct distro. For example, you would set DISTRO=centos when running from an oraclelinux base image.
• PROFILES The bindep profiles to specify to configure which packages get installed. This is a space sperated list.
• PIP_PACKAGES Specify additional packages you would like installed. The only caveat is these packages must exist in your WHEELS tarball. So if you wanted to include rpdb, you would need to have built that into your WHEELS.

This makes it really easy to integrate LOCI images into your development or CI/CD workflow, for example, if you wanted to build an image from this PS you could run:

$ docker build https://git.openstack.org/openstack/loci.git \
    --build-arg PROJECT=keystone \
    --tag mydockernamespace/keystone-testing:418167-1 \
    --build-arg PROJECT_REF=refs/changes/67/418167/1

To build with the wheels from a private Docker registry rather than DockerHub run:

$ docker build https://git.openstack.org/openstack/loci.git \
    --build-arg PROJECT=keystone \
    --build-arg WHEELS=172.17.0.1:5000/mydockernamespace/keystone:ubuntu

To build cinder with lvm and ceph support you would run:

$ docker build https://git.openstack.org/openstack/loci.git \
    --build-arg PROJECT=cinder \
    --build-arg PROFILES="lvm ceph"

Customizing

The images should contain all the required assets for running the service. But if you wish or need to customize the loci/keystone image that's great! We hope to have built the images to make this as easy and flexible as possible. To do this we recommend that you perform any required customisation in a child image using a pattern similar to:

FROM loci/keystone:master-ubuntu
MAINTAINER you@example.com

RUN set -x \
    && apt-get update \
    && apt-get install -y --no-install-recommends your-awesome-binary-package \
    && rm -rf /var/lib/apt/lists/*

A Note on the Stability of LOCI

LOCI is still a relatively young project. While some of us have been using it for going on a year, we have made breaking changes a few times while we flesh out the best way to achieve goals. We are targeting a 1.0.0 release for OpenStack Queens and will be following upstream practices as far as tagging and branching.

We will be adding in a stable/ocata and stable/pike branch (possibly an eol-newton and eol-mitaka tag as well) over the next few months so we can build images for these versions of OpenStack as well. While the master branch of LOCI is currently capable of building all of these versions right now, we will be maintaining stable branches going forward so as not to rely on compatibility for all versions of OpenStack on one branch.

We highly encourage people to use this, and some have even adopted it into build pipelines internally already.