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Docker Images

GoReleaser can build and push Docker images. Let's see how it works.

How it works

You can declare multiple Docker images. They will be matched against the binaries generated by your builds section and packages generated by your nfpms section.

If you have only one build setup, the configuration is as easy as adding the name of your image to your .goreleaser.yml file:

dockers:
  - image_templates:
    - user/repo

Tip

The image_templates attribute supports templating. Learn more about the name template engine.

You also need to create a Dockerfile in your project's root folder:

FROM scratch
ENTRYPOINT ["/mybin"]
COPY mybin /

This configuration will build and push a Docker image named user/repo:tagname.

Warning

Note that we are not building any go files in the Docker build phase, we are merely copying the binary to a scratch image and setting up the entrypoint.

Customization

Of course, you can customize a lot of things:

# .goreleaser.yml
dockers:
  # You can have multiple Docker images.
  -
    # ID of the image, needed if you want to filter by it later on (e.g. on custom publishers).
    id: myimg

    # GOOS of the built binaries/packages that should be used.
    goos: linux

    # GOARCH of the built binaries/packages that should be used.
    goarch: amd64

    # GOARM of the built binaries/packages that should be used.
    goarm: ''

    # IDs to filter the binaries/packages.
    ids:
    - mybuild
    - mynfpm

    # Templates of the Docker image names.
    image_templates:
    - "myuser/myimage:latest"
    - "myuser/myimage:{{ .Tag }}"
    - "myuser/myimage:{{ .Tag }}-{{ .Env.GO_VERSION }}"
    - "myuser/myimage:v{{ .Major }}"
    - "gcr.io/myuser/myimage:latest"

    # Skips the docker push.
    # Could be useful if you also do draft releases.
    #
    # If set to auto, the release will not be pushed to the Docker repository
    #  in case there is an indicator of a prerelease in the tag, e.g. v1.0.0-rc1.
    #
    # Defaults to false.
    skip_push: false

    # Path to the Dockerfile (from the project root).
    dockerfile: Dockerfile

    # Set the "backend" for the Docker pipe.
    # Valid options are: docker, buildx, podman, buildpacks
    # podman is a GoReleaser Pro feature and is only available on Linux.
    # Defaults to docker.
    use: docker

    # Template of the docker build flags.
    build_flag_templates:
    - "--pull"
    - "--label=org.opencontainers.image.created={{.Date}}"
    - "--label=org.opencontainers.image.title={{.ProjectName}}"
    - "--label=org.opencontainers.image.revision={{.FullCommit}}"
    - "--label=org.opencontainers.image.version={{.Version}}"
    - "--build-arg=FOO={{.Env.Bar}}"
    - "--platform=linux/arm64"

    # Extra flags to be passed down to the push command.
    # Defaults to empty.
    push_flags:
    - --tls-verify=false

    # If your Dockerfile copies files other than binaries and packages,
    # you should list them here as well.
    # Note that GoReleaser will create the same structure inside a temporary
    # folder, so if you add `foo/bar.json` here, on your Dockerfile you can
    # `COPY foo/bar.json /whatever.json`.
    # Also note that the paths here are relative to the folder in which
    # GoReleaser is being run (usually the repository root folder).
    # This field does not support wildcards, you can add an entire folder here
    # and use wildcards when you `COPY`/`ADD` in your Dockerfile.
    extra_files:
    - config.yml

Tip

Learn more about the name template engine.

Tip

You can also create multi-platform images using the docker_manifests config.

These settings should allow you to generate multiple Docker images, for example, using multiple FROM statements, as well as generate one image for each binary in your project or one image with multiple binaries, as well as install the generated packages instead of copying the binary and configs manually.

Generic Image Names

Some users might want to keep their image name as generic as possible. That can be accomplished simply by adding template language in the definition:

# .goreleaser.yml
project: foo
dockers:
  -
    image_templates:
    - "myuser/{{.ProjectName}}"

This will build and publish the following images:

  • myuser/foo

Tip

Learn more about the name template engine.

Keeping docker images updated for current major

Some users might want to push docker tags :v1, :v1.6, :v1.6.4 and :latest when v1.6.4 (for example) is built. That can be accomplished by using multiple image_templates:

# .goreleaser.yml
dockers:
  -
    image_templates:
    - "myuser/myimage:{{ .Tag }}"
    - "myuser/myimage:v{{ .Major }}"
    - "myuser/myimage:v{{ .Major }}.{{ .Minor }}"
    - "myuser/myimage:latest"

This will build and publish the following images:

  • myuser/myimage:v1.6.4
  • myuser/myimage:v1
  • myuser/myimage:v1.6
  • myuser/myimage:latest

With these settings you can hopefully push several Docker images with multiple tags.

Tip

Learn more about the name template engine.

Publishing to multiple docker registries

Some users might want to push images to multiple docker registries. That can be accomplished by using multiple image_templates:

# .goreleaser.yml
dockers:
  -
    image_templates:
    - "docker.io/myuser/myimage:{{ .Tag }}"
    - "docker.io/myuser/myimage:latest"
    - "gcr.io/myuser/myimage:{{ .Tag }}"
    - "gcr.io/myuser/myimage:latest"

This will build and publish the following images to docker.io and gcr.io:

  • myuser/myimage:v1.6.4
  • myuser/myimage:latest
  • gcr.io/myuser/myimage:v1.6.4
  • gcr.io/myuser/myimage:latest

Applying Docker build flags

Build flags can be applied using build_flag_templates. The flags must be valid Docker build flags.

# .goreleaser.yml
dockers:
  -
    image_templates:
    - "myuser/myimage"
    build_flag_templates:
    - "--pull"
    - "--label=org.opencontainers.image.created={{.Date}}"
    - "--label=org.opencontainers.image.title={{.ProjectName}}"
    - "--label=org.opencontainers.image.revision={{.FullCommit}}"
    - "--label=org.opencontainers.image.version={{.Version}}"

This will execute the following command:

docker build -t myuser/myimage . \
  --pull \
  --label=org.opencontainers.image.created=2020-01-19T15:58:07Z \
  --label=org.opencontainers.image.title=mybinary \
  --label=org.opencontainers.image.revision=da39a3ee5e6b4b0d3255bfef95601890afd80709 \
  --label=org.opencontainers.image.version=1.6.4

Tip

Learn more about the name template engine.

Podman

GoReleaser Pro

The podman backend is a GoReleaser Pro feature.

You can use podman instead of docker by setting use to podman on your config:

# .goreleaser.yml
dockers:
  -
    image_templates:
    - "myuser/myimage"
    use: podman

Note that GoReleaser will not install Podman for you, nor change any of its configuration.

Buildpacks

You can use buildpacks instead of docker by setting use to buildpacks on your config:

# .goreleaser.yml
dockers:
  -
    image_templates:
    - "myuser/myimage"
    use: buildpacks

Also, you can use a custom buildpack on build_flag_templates if you want. By default, gcr.io/buildpacks/builder:v1 will be used.

# .goreleaser.yml
dockers:
  -
    image_templates:
    - "myuser/myimage"
    use: buildpacks
    build_flag_templates:
    - "--builder=heroku/buildpacks:20"