About

GitHub Action to use Docker Buildx Bake as a high-level build command.

---

• Usage
• Subactions
  • list-targets
• Customizing
  • inputs
  • outputs
• Contributing

Usage

name: ci

on:
  push:
    branches:
      - 'master'

jobs:
  bake:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      -
        name: Login to DockerHub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      -
        name: Build and push
        uses: docker/bake-action@v4
        with:
          push: true

Subactions

list-targets

This subaction generates a list of Bake targets that can be used in a GitHub matrix, so you can distribute your builds across multiple runners.

# docker-bake.hcl
group "validate" {
  targets = ["lint", "doctoc"]
}

target "lint" {
  target = "lint"
}

target "doctoc" {
  target = "doctoc"
}

jobs:
  prepare:
    runs-on: ubuntu-latest
    outputs:
      targets: ${{ steps.generate.outputs.targets }}
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: List targets
        id: generate
        uses: docker/bake-action/subaction/list-targets@v4
        with:
          target: validate

  validate:
    runs-on: ubuntu-latest
    needs:
      - prepare
    strategy:
      fail-fast: false
      matrix:
        target: ${{ fromJson(needs.prepare.outputs.targets) }}
    steps:
      -
        name: Checkout
        uses: actions/checkout@v4
      -
        name: Validate
        uses: docker/bake-action@v4
        with:
          targets: ${{ matrix.target }}

Customizing

inputs

Following inputs can be used as step.with keys

List type is a newline-delimited string

set: target.args.mybuildarg=value

set: |
  target.args.mybuildarg=value
  foo*.args.mybuildarg=value

CSV type is a comma-delimited string

targets: default,release

Name	Type	Description
builder	String	Builder instance (see setup-buildx action)
files	List/CSV	List of bake definition files
workdir	String	Working directory of execution
targets	List/CSV	List of bake targets (default target used if empty)
no-cache	Bool	Do not use cache when building the image (default false)
pull	Bool	Always attempt to pull a newer version of the image (default false)
load	Bool	Load is a shorthand for --set=*.output=type=docker (default false)
provenance	Bool/String	Provenance is a shorthand for --set=*.attest=type=provenance
push	Bool	Push is a shorthand for --set=*.output=type=registry (default false)
sbom	Bool/String	SBOM is a shorthand for --set=*.attest=type=sbom
set	List	List of targets values to override (eg: targetpattern.key=value)
source	String	Remote bake definition to build from

outputs

The following outputs are available

Name	Type	Description
metadata	JSON	Build result metadata

Contributing

Want to contribute? Awesome! You can find information about contributing to this project in the CONTRIBUTING.md