Kolla Configuration

Anyone using Kayobe to build images should familiarise themselves with the Kolla project’s documentation.

Container Image Build Host

Images are built on hosts in the container-image-builders group. The default Kayobe Ansible inventory places the seed host in this group, although it is possible to put a different host in the group, by modifying the inventory.

For example, to build images on localhost:

inventory/groups

[container-image-builders:children]

inventory/hosts

[container-image-builders]
localhost

Kolla Installation

Prior to building container images, Kolla and its dependencies will be installed on the container image build host. The following variables affect the installation of Kolla:

kolla_ctl_install_type

Type of installation, either binary (PyPI) or source (git). Default is source.

kolla_source_path

Path to directory for Kolla source code checkout. Default is {{ source_checkout_path ~ '/kolla' }}.

kolla_source_url

URL of Kolla source code repository if type is source. Default is https://opendev.org/openstack/kolla.

kolla_source_version

Version (branch, tag, etc.) of Kolla source code repository if type is source. Default is {{ openstack_branch }}, which is the same as the Kayobe upstream branch name.

kolla_venv

Path to virtualenv in which to install Kolla on the container image build host. Default is {{ virtualenv_path ~ '/kolla' }}.

kolla_build_config_path

Path in which to generate kolla configuration. Default is {{ config_path ~ '/kolla' }}.

For example, to install from a custom Git repository:

kolla.yml

kolla_source_url: https://git.example.com/kolla
kolla_source_version: downstream

Global Configuration

The following variables are global, affecting all container images. They are used to generate the Kolla configuration file, kolla-build.conf, and also affect Kolla Ansible configuration.

kolla_base_distro

Kolla base container image distribution. Options are centos, debian, or ubuntu. Default is {{ os_distribution }}.

kolla_install_type

Kolla container image type: binary or source. Default is source.

kolla_docker_namespace

Docker namespace to use for Kolla images. Default is kolla.

kolla_docker_registry

URL of docker registry to use for Kolla images. Default is to use the value of docker_registry variable (see Docker Engine).

kolla_docker_registry_username

Username to use to access a docker registry. Default is not set, in which case the registry will be used without authentication.

kolla_docker_registry_password

Password to use to access a docker registry. Default is not set, in which case the registry will be used without authentication.

kolla_openstack_release

Kolla OpenStack release version. This should be a Docker image tag. Default is the OpenStack release name (e.g. rocky) on stable branches and tagged releases, or master on the Kayobe master branch.

kolla_tag

Kolla container image tag. This is the tag that will be applied to built container images. Default is kolla_openstack_release.

For example, to build the Kolla centos binary images with a namespace of example, and a private Docker registry at registry.example.com:4000, tagged with 7.0.0.1:

kolla.yml

kolla_base_distro: centos
kolla_install_type: binary
kolla_docker_namespace: example
kolla_docker_registry: registry.example.com:4000
kolla_openstack_release: 7.0.0.1

The ironic-api image built with this configuration would be referenced as follows:

registry.example.com:4000/example/centos-binary-ironic-api:7.0.0.1

Further customisation of the Kolla configuration file can be performed by writing a file at ${KAYOBE_CONFIG_PATH/kolla/kolla-build.conf. For example, to enable debug logging:

kolla/kolla-build.conf

[DEFAULT]
debug = True

Seed Images

The kayobe seed container image build command builds images for the seed services. The only image required for the seed services is the bifrost-deploy image.

Overcloud Images

The kayobe overcloud container image build command builds images for the control plane. The default set of images built depends on which services and features are enabled via the kolla_enable_<service> flags in $KAYOBE_CONFIG_PATH/kolla.yml.

For example, the following configuration will enable the Magnum service and add the magnum-api and magnum-conductor containers to the set of overcloud images that will be built:

kolla.yml

kolla_enable_magnum: true

If a required image is not built when the corresponding flag is set, check the image sets defined in overcloud_container_image_sets in ansible/group_vars/all/kolla.

Image Customisation

There are three main approaches to customising the Kolla container images:

1. Overriding Jinja2 blocks

2. Overriding Jinja2 variables

3. Source code locations

Overriding Jinja2 blocks

Kolla’s images are defined via Jinja2 templates that generate Dockerfiles. Jinja2 blocks are frequently used to allow specific statements in one or more Dockerfiles to be replaced with custom statements. See the Kolla documentation for details.

Blocks are configured via the kolla_build_blocks variable, which is a dict mapping Jinja2 block names in to their contents.

For example, to override the block header to add a custom label to every image:

kolla.yml

kolla_build_blocks:
  header: |
    LABEL foo="bar"

This will result in Kayobe generating a template-override.j2 file with the following content:

template-override.j2

{% extends parent_template %}

{% block header %}
LABEL foo="bar"
{% endblock %}

Overriding Jinja2 variables

Jinja2 variables offer another way to customise images. See the Kolla documentation for details of using variable overrides to modify the list of packages to install in an image.

Variable overrides are configured via the kolla_build_customizations variable, which is a dict/map mapping names of variables to override to their values.

For example, to add mod_auth_openidc to the list of packages installed in the keystone-base image, we can set the variable keystone_base_packages_append to a list containing mod_auth_openidc.

kolla.yml

kolla_build_customizations:
  keystone_base_packages_append:
    - mod_auth_openidc

This will result in Kayobe generating a template-override.j2 file with the following content:

template-override.j2

{% extends parent_template %}

{% set keystone_base_packages_append = ["mod_auth_openidc"] %}

Note that the variable value will be JSON-encoded in template-override.j2.

Source code locations

For source image builds, configuration of source code locations for packages installed in containers by Kolla is possible via the kolla_sources variable. The format is a dict/map mapping names of sources to their definitions. See the Kolla documentation for details. The default is to specify the URL and version of Bifrost, as defined in ${KAYOBE_CONFIG_PATH}/bifrost.yml.

For example, to specify a custom source location for the ironic-base package:

kolla.yml

kolla_sources:
  bifrost-base:
    type: "git"
    location: "{{ kolla_bifrost_source_url }}"
    reference: "{{ kolla_bifrost_source_version }}"
  ironic-base:
    type: "git"
    location: https://git.example.com/ironic
    reference: downstream

This will result in Kayobe adding the following configuration to kolla-build.conf:

kolla-build.conf

[bifrost-base]
type = git
location = https://opendev.org/openstack/bifrost
reference = stable/rocky

[ironic-base]
type = git
location = https://git.example.com/ironic
reference = downstream

Note that it is currently necessary to include the Bifrost source location if using a seed.

Plugins & additions

These features can also be used for installing plugins and additions to source type images.

For example, to install a networking-ansible plugin in the neutron-server image:

kolla.yml

kolla_sources:
  bifrost-base:
    type: "git"
    location: "{{ kolla_bifrost_source_url }}"
    reference: "{{ kolla_bifrost_source_version }}"
  neutron-server-plugin-networking-ansible:
    type: "git"
    location: https://git.example.com/networking-ansible
    reference: downstream

The neutron-server image automatically installs any plugins provided to it. For images that do not, a block such as the following may be required:

kolla.yml

kolla_build_blocks:
  neutron_server_footer: |
    ADD plugins-archive /
    pip --no-cache-dir install /plugins/*

A similar approach may be used for additions.