Docker Compose Buildkite Plugin

A Buildkite plugin that lets you build, run and push build steps using Docker Compose.

• Containers are built, run and linked on demand using Docker Compose
• Containers are namespaced to each build job, and cleaned up after use
• Supports pre-building of images, allowing for fast parallel builds across distributed agents
• Supports pushing tagged images to a repository

Example

The following pipeline will run test.sh inside a app service container using Docker Compose, the equivalent to running docker-compose run app test.sh:

steps:
  - command: test.sh
    plugins:
      - docker-compose#v3.10.0:
          run: app

You can also specify a custom Docker Compose config file and what environment to pass through if you need:

steps:
  - command: test.sh
    plugins:
      - docker-compose#v3.10.0:
          run: app
          config: docker-compose.tests.yml
          env:
            - BUILDKITE_BUILD_NUMBER

or multiple config files:

steps:
  - command: test.sh
    plugins:
      - docker-compose#v3.10.0:
          run: app
          config:
            - docker-compose.yml
            - docker-compose.test.yml

You can also specify the Docker Compose config file with $COMPOSE_FILE:

env:
  COMPOSE_FILE: docker-compose.yml
steps:
  - command: test.sh
    plugins:
      - docker-compose#v3.10.0:
          run: app

You can leverage the docker-login plugin in tandem for authenticating with a registry. For example, the following will build and push an image to a private repo, and pull from that private repo in subsequent run commands:

steps:
  - plugins:
      - docker-login#v2.0.1:
          username: xyz
      - docker-compose#v3.10.0:
          build: app
          image-repository: index.docker.io/myorg/myrepo
  - wait
  - command: test.sh
    plugins:
      - docker-login#v2.0.1:
          username: xyz
      - docker-compose#v3.10.0:
          run: app

If you want to control how your command is passed to docker-compose, you can use the command parameter on the plugin directly:

steps:
  - plugins:
      - docker-compose#v3.10.0:
          run: app
          command: ["custom", "command", "values"]

Artifacts

If you’re generating artifacts in the build step, you’ll need to ensure your Docker Compose configuration volume mounts the host machine directory into the container where those artifacts are created.

For example, if you had the following step:

steps:
  - command: generate-dist.sh
    artifact_paths: "dist/*"
    plugins:
      - docker-compose#v3.10.0:
          run: app

Assuming your application’s directory inside the container was /app, you would need to ensure your app service in your Docker Compose config has the following host volume mount:

volumes:
  - "./dist:/app/dist"

You can also use the volumes plugin option to add or override a volume, for example:

steps:
  - command: generate-dist.sh
    artifact_paths: "dist/*"
    plugins:
      - docker-compose#v3.10.0:
          run: app
          volumes:
            - "./dist:/app/dist"

Environment

By default, docker-compose makes whatever environment variables it gets available for interpolation of docker-compose.yml, but it doesn't pass them in to your containers.

You can use the environment key in docker-compose.yml to either set specific environment vars or "pass through" environment variables from outside docker-compose.

If you want to add extra environment above what is declared in your docker-compose.yml, this plugin offers a environment block of it's own:

steps:
  - command: generate-dist.sh
    plugins:
      - docker-compose#v3.10.0:
          run: app
          env:
            - BUILDKITE_BUILD_NUMBER
            - BUILDKITE_PULL_REQUEST
            - MY_CUSTOM_ENV=llamas

Note how the values in the list can either be just a key (so the value is sourced from the environment) or a KEY=VALUE pair.

Build Arguments

You can use the build args key in docker-compose.yml to set specific build arguments when building an image.

Alternatively, if you want to set build arguments when pre-building an image, this plugin offers an args block of it's own:

steps:
  - command: generate-dist.sh
    plugins:
      - docker-compose#v3.10.0:
          build: app
          image-repository: index.docker.io/myorg/myrepo
          args:
            - MY_CUSTOM_ARG=panda

Note that the values in the list must be a KEY=VALUE pair.

Pre-building the image

To speed up run steps that use the same service/image (such as steps that run in parallel), you can add a pre-build step to your pipeline:

steps:
  - label: ":docker: Build"
    plugins:
      - docker-compose#v3.10.0:
          build: app
          image-repository: index.docker.io/myorg/myrepo

  - wait

  - label: ":docker: Test %n"
    command: test.sh
    parallelism: 25
    plugins:
      - docker-compose#v3.10.0:
          run: app

All run steps for the service app will automatically pull and use the pre-built image.

Building multiple images

Sometimes your compose file has multiple services that need building. The example below will build images for the app and tests service and then the run step will pull them down and use them for the run as needed.

steps:
  - label: ":docker: Build"
    agents:
      queue: docker-builder
    plugins:
      - docker-compose#v3.10.0:
          build:
            - app
            - tests
          image-repository: index.docker.io/myorg/myrepo

  - wait

  - label: ":docker: Test %n"
    command: test.sh
    parallelism: 25
    plugins:
      - docker-compose#v3.10.0:
          run: tests

Pushing Tagged Images

If you want to push your Docker images ready for deployment, you can use the push configuration (which operates similar to docker-compose push:

steps:
  - label: ":docker: Push"
    plugins:
      - docker-compose#v3.10.0:
          push: app

If you need to authenticate to the repository to push (e.g. when pushing to Docker Hub), use the Docker Login plugin:

steps:
  - label: ":docker: Push"
    plugins:
      - docker-login#v2.0.1:
          username: xyz
      - docker-compose#v3.10.0:
          push: app

To push multiple images, you can use a list:

steps:
  - label: ":docker: Push"
    plugins:
      - docker-login#v2.0.1:
          username: xyz
      - docker-compose#v3.10.0:
          push:
            - first-service
            - second-service

If you want to push to a specific location (that's not defined as the image in your docker-compose.yml), you can use the {service}:{repo}:{tag} format, for example:

steps:
  - label: ":docker: Push"
    plugins:
      - docker-login#v2.0.1:
          username: xyz
      - docker-compose#v3.10.0:
          push:
          - app:index.docker.io/myorg/myrepo/myapp
          - app:index.docker.io/myorg/myrepo/myapp:latest

Reusing caches from images

A newly spawned agent won't contain any of the docker caches for the first run which will result in a long build step. To mitigate this you can reuse caches from a previously built image (if it was pushed from a previous build):

steps:
  - label: ":docker: Build an image"
    plugins:
      - docker-compose#v3.10.0:
          build: app
          image-repository: index.docker.io/myorg/myrepo
          cache-from: app:index.docker.io/myorg/myrepo/myapp:latest
  - wait
  - label: ":docker: Push to final repository"
    plugins:
      - docker-compose#v3.10.0:
          push:
          - app:index.docker.io/myorg/myrepo/myapp
          - app:index.docker.io/myorg/myrepo/myapp:latest

Configuration

build

The name of a service to build and store, allowing following pipeline steps to run faster as they won't need to build the image. The step’s command will be ignored and does not need to be specified.

Either a single service or multiple services can be provided as an array.

run

The name of the service the command should be run within. If the docker-compose command would usually be docker-compose run app test.sh then the value would be app.

push

A list of services to push in the format service:image:tag. If an image has been pre-built with the build step, that image will be re-tagged, otherwise docker-compose's built in push operation will be used.

pull (optional, run only)

Pull down multiple pre-built images. By default only the service that is being run will be pulled down, but this allows multiple images to be specified to handle prebuilt dependent images.

config (optional)

The file name of the Docker Compose configuration file to use. Can also be a list of filenames. If $COMPOSE_FILE is set, it will be used if config is not specified.

Default: docker-compose.yml

image-repository (optional, build only)

The repository for pushing and pulling pre-built images, same as the repository location you would use for a docker push, for example "index.docker.io/myorg/myrepo". Each image is tagged to the specific build so you can safely share the same image repository for any number of projects and builds.

The default is "" which only builds images on the local Docker host doing the build.

This option can also be configured on the agent machine using the environment variable BUILDKITE_PLUGIN_DOCKER_COMPOSE_IMAGE_REPOSITORY.

image-name (optional, build only)

The name to use when tagging pre-built images. If multiple images are built in the build phase, you must provide an array of image names.

build-alias (optional, build only)

Other docker-compose services that should be aliased to the main service that was built. This is for when different docker-compose services share the same prebuilt image.

args (optional, build and run only)

A list of KEY=VALUE that are passed through as build arguments when image is being built.

env or environment (optional, run only)

A list of either KEY or KEY=VALUE that are passed through as environment variables to the container.

command (optional, run only, array)

Sets the command for the Docker image, and defaults the shell option to false. Useful if the Docker image has an entrypoint, or doesn't contain a shell.

This option can't be used if your step already has a top-level, non-plugin command option present.

Examples: [ "/bin/mycommand", "-c", "test" ], ["arg1", "arg2"]

shell (optional, run only, array or boolean)

Set the shell to use for the command. Set it to false to pass the command directly to the docker-compose run command. The default is ["/bin/sh", "-e", "-c"] unless you have provided a command.

Example: [ "powershell", "-Command" ]

skip-checkout (optional, run only)

Whether to skip the repository checkout phase. This is useful for steps that use a pre-built image. This will fail if there is no pre-built image.

workdir (optional, run only)

Specify the container working directory via docker-compose run --workdir.

user (optional, run only)

Run as specified username or uid via docker-compose run --user.

propagate-uid-gid (optional, run-only, boolean)

Whether to match the user ID and group ID for the container user to the user ID and group ID for the host user. It is similar to specifying user: 1000:1000, except it avoids hardcoding a particular user/group ID.

Using this option ensures that any files created on shared mounts from within the container will be accessible to the host user. It is otherwise common to accidentally create root-owned files that Buildkite will be unable to remove, since containers by default run as the root user.

mount-ssh-agent (optional, run-only, boolean)

Whether to automatically mount the ssh-agent socket from the host agent machine into the container (at /ssh-agentand /root/.ssh/known_hosts respectively), allowing git operations to work correctly.

Default: false

mount-buildkite-agent (optional, run-only, boolean)

Whether to automatically mount the buildkite-agent binary and associated environment variables from the host agent machine into the container.

Default: false

pull-retries (optional)

A number of times to retry failed docker pull. Defaults to 0.

This option can also be configured on the agent machine using the environment variable BUILDKITE_PLUGIN_DOCKER_COMPOSE_PULL_RETRIES.

push-retries (optional)

A number of times to retry failed docker push. Defaults to 0.

This option can also be configured on the agent machine using the environment variable BUILDKITE_PLUGIN_DOCKER_COMPOSE_PUSH_RETRIES.

cache-from (optional, build only)

A list of images to pull caches from in the format service:index.docker.io/myorg/myrepo/myapp:tag before building, ignoring any failures. If multiple images are listed for a service, the first one to successfully pull will be used. Requires docker-compose file version 3.2+.

volumes (optional, run only)

A list of volumes to mount into the container. If a matching volume exists in the Docker Compose config file, this option will override that definition.

Additionally, volumes may be specified via the agent environment variable BUILDKITE_DOCKER_DEFAULT_VOLUMES, a ; (semicolon) delimited list of mounts in the -v syntax. (Ex. buildkite:/buildkite;./app:/app).

graceful-shutdown (optional, run only)

Gracefully shuts down all containers via 'docker-compose stop`.

The default is false.

leave-volumes (optional, run only)

Prevent the removal of volumes after the command has been run.

The default is false.

no-cache (optional, build and run only)

Build with --no-cache, causing Docker Compose to not use any caches when building the image.

The default is false.

build-parallel (optional, build and run only)

Build with --parallel, causing Docker Compose to run builds in parallel. Requires docker-compose 1.23+.

The default is false.

tty (optional, run only)

If set to false, doesn't allocate a TTY. This is useful in some situations where TTY's aren't supported, for instance windows.

The default is true on unix, false on windows

dependencies (optional, run only)

If set to false, doesn't start linked services.

The default is true.

ansi (optional, run only)

If set to false, disables the ansi output from containers.

The default is true.

use-aliases (optional, run only)

If set to true, docker compose will use the service's network aliases in the network(s) the container connects to.

The default is false.

verbose (optional)

Sets docker-compose to run with --verbose

The default is false.

rm (optional, run only)

If set to true, docker compose will remove the primary container after run. Equivalent to --rm in docker-compose.

The default is true.

entrypoint (optional, run only)

Sets the --entrypoint argument when running docker-compose.

upload-container-logs (optional, run only)

Select when to upload container logs.

• on-error Upload logs for all containers when an error occurs
• always Always upload logs for all container
• never Never upload logs for all container

The default is on-error.

Developing

To run the tests:

docker-compose run --rm tests

License

MIT (see LICENSE)