James E. Blair 1c827e4761 docker: prefix role vars
These probably should have been prefixed to start with.  The roles
are brand new, not publicised, and likely not widely used.  I think
we can merge this without announcement or deprecation.

Change-Id: I7825ef6fee1325b6d4fcc179032652eb5530d016
2019-01-17 11:28:37 -08:00

99 lines
3.3 KiB
ReStructuredText

This is one of a collection of roles which are designed to work
together to build, upload, and promote docker images in a gating
context:
* :zuul:role:`build-docker-image`: Build the images.
* :zuul:role:`upload-docker-image`: Stage the images on dockerhub.
* :zuul:role:`promote-docker-image`: Promote previously uploaded images.
The :zuul:role:`build-docker-image` role is designed to be used in
`check` and `gate` pipelines and simply builds the images. It can be
used to verify that the build functions, or it can be followed by the
use of subsequent roles to upload the images to Docker Hub.
The :zuul:role:`upload-docker-image` role uploads the images to Docker
Hub, but only with a single tag corresponding to the change ID. This
role is designed to be used in a job in a `gate` pipeline so that the
build produced by the gate is staged and can later be promoted to
production if the change is successful.
The :zuul:role:`promote-docker-image` role is designed to be used in a
`promote` pipeline. It requires no nodes and runs very quickly on the
Zuul executor. It simply re-tags a previously uploaded image for a
change with whatever tags are supplied by the
:zuul:rolevar:`build-docker-image.docker_images.context`. It also
removes the change ID tag from the repository in Docker Hub, and
removes any similar change ID tags more than 24 hours old. This keeps
the repository tidy in the case that gated changes fail to merge after
uploading their staged images.
They all accept the same input data, principally a list of
dictionaries representing the images to build. YAML anchors_ can be
used to supply the same data to all three jobs.
Use the :zuul:role:`install-docker` role to install Docker before
using this role.
**Role Variables**
.. zuul:rolevar:: zuul_work_dir
:default: {{ zuul.project.src_dir }}
The project directory. Serves as the base for
:zuul:rolevar:`build-docker-image.docker_images.context`.
.. zuul:rolevar:: docker_credentials
:type: dict
This is only required for the upload and promote roles. This is
expected to be a Zuul Secret with two keys:
.. zuul:rolevar:: username
The Docker Hub username.
.. zuul:rolevar:: password
The Docker Hub password
.. zuul:rolevar:: docker_images
:type: list
A list of images to build. Each item in the list should have:
.. zuul:rolevar:: context
The docker build context; this should be a directory underneath
:zuul:rolevar:`build-docker-image.zuul_work_dir`.
.. zuul:rolevar:: repository
The name of the target repository in dockerhub for the
image. Supply this even if the image is not going to be
uploaded (it will be tagged with this in the local
registry).
.. zuul:rolevar:: path
Optional: the directory that should be passed to docker build.
Useful for building images with a Dockerfile in the context
directory but a source repository elsewhere.
.. zuul:jobvar:: build_args
:type: list
Optional: a list of values to pass to the docker ``--build-arg``
parameter.
.. zuul:rolevar:: target
Optional: the target for a multi-stage build.
.. zuul:jobvar:: tags
:type: list
:default: ['latest']
A list of tags to be added to the image when promoted.
.. _anchors: https://yaml.org/spec/1.2/spec.html#&%20anchor//