Workflow definitions for Docker applications

docker-multi-arch.yml

# A workflow that has different architectures split into multiple Dockerfiles.
# Creates a single multi-arch image at the end.

name: Publish Docker

on:
  push:
    branches: [ "master" ]
  pull_request:
    branches: [ "master" ]
  workflow_dispatch: {}

env:
  # Use docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:

    runs-on: ubuntu-latest
    
    permissions:
      contents: read
      packages: write
      id-token: write
      attestations: write

    strategy:
      matrix:
        include:
          - dockerfile: linux-amd64.Dockerfile
            dockerplatform: linux/amd64
            arch: amd64
          - dockerfile: linux-arm64.Dockerfile
            dockerplatform: linux/arm64
            arch: arm64

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      # Install the cosign tool except on PR
      # https://github.com/sigstore/cosign-installer
      - name: Install cosign
        if: github.event_name != 'pull_request'
        uses: sigstore/cosign-installer@v3.5.0
        with:
          cosign-release: 'v2.2.4'

      # Set up BuildKit Docker container builder to be able to build
      # multi-platform images and export cache
      # https://github.com/docker/setup-buildx-action
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3.3.0

      # Login against a Docker registry except on PR
      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3.1.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract metadata (tags, labels) for Docker
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5.5.1
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          flavor: |
            suffix=-${{ matrix.arch }},onlatest=true
          tags: |
            # set latest tag for default branch
            type=raw,value=latest,enable={{is_default_branch}}
            type=ref,event=branch
            type=ref,event=tag
            type=sha

      # Build and push Docker image with Buildx (don't push on PR)
      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v5.3.0
        with:
          context: .
          file: ${{ matrix.dockerfile }}
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: ${{ matrix.dockerplatform }}
          #cache-from: type=gha
          #cache-to: type=gha,mode=max

      - name: Print tags summary
        if: github.event_name != 'pull_request'
        run: |
          all_tags="${{ steps.meta.outputs.tags }}"
          echo -e "### Pushed:\n$(echo $all_tags | jq -Rrsc 'split(" ")[] | "- \(.)"')" >> $GITHUB_STEP_SUMMARY

      - name: Generate image artifact attestation
        if: github.event_name != 'pull_request'
        uses: actions/attest-build-provenance@v1
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          subject-digest: ${{ steps.build-and-push.outputs.digest }}
          push-to-registry: true

      # Sign the resulting Docker image digest except on PRs.
      # This will only write to the public Rekor transparency log when the Docker
      # repository is public to avoid leaking data.  If you would like to publish
      # transparency data even for private images, pass --force to cosign below.
      # https://github.com/sigstore/cosign
      - name: Sign the published Docker image
        if: github.event_name != 'pull_request'
        env:
          # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
          TAGS: ${{ steps.meta.outputs.tags }}
          DIGEST: ${{ steps.build-and-push.outputs.digest }}
        # This step uses the identity token to provision an ephemeral certificate
        # against the sigstore community Fulcio instance.
        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}

      - name: Write tags artifact
        if: github.event_name != 'pull_request'
        run: |
          echo "${{ steps.meta.outputs.tags }}" > tags.txt
      - name: Upload tags list artifact
        if: github.event_name != 'pull_request'
        uses: actions/upload-artifact@v4
        with:
          name: ${{ matrix.arch }}-tags
          path: tags.txt

  combine:

    runs-on: ubuntu-latest
    if: github.event_name != 'pull_request'
    needs: build

    permissions:
      contents: read
      packages: write
      id-token: write
      attestations: write

    steps:
      - name: Download tags.txt
        uses: actions/download-artifact@v4
      - name: Read tags.txt
        id: tags
        run: |
          echo "arm64_tag=$(grep -m 1 ':sha-' arm64-tags/tags.txt)" >> $GITHUB_OUTPUT
          echo "amd64_tag=$(grep -m 1 ':sha-' amd64-tags/tags.txt)" >> $GITHUB_OUTPUT

      # Install the cosign tool except on PR
      # https://github.com/sigstore/cosign-installer
      - name: Install cosign
        uses: sigstore/cosign-installer@v3.5.0
        with:
          cosign-release: 'v2.2.4'

      # Set up BuildKit Docker container builder to be able to build
      # multi-platform images and export cache
      # https://github.com/docker/setup-buildx-action
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3.3.0

      # Login against a Docker registry except on PR
      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3.1.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract metadata (tags, labels) for Docker
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5.5.1
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            # set latest tag for default branch
            type=raw,value=latest,enable={{is_default_branch}}
            type=ref,event=branch
            type=ref,event=tag
            type=sha

      - name: Create multi-platform image
        id: create
        run: |
          set -x
          all_tags="${{ steps.meta.outputs.tags }}"
          tags=$(echo $all_tags | jq -Rrsc 'split(" ")[] | "-t \(.) "')
          
          docker buildx imagetools create $tags ${{ steps.tags.outputs.arm64_tag }} ${{ steps.tags.outputs.amd64_tag }}
          digest="$(docker buildx imagetools inspect $(echo $all_tags | jq -Rrsc 'split(" ") | .[0]') --format '{{json .Manifest}}' | jq -r '.digest')"
          
          echo "digest=${digest}" >> $GITHUB_OUTPUT
          echo -e "### Pushed:\n$(echo $all_tags | jq -Rrsc 'split(" ")[] | "- \(.)"')" >> $GITHUB_STEP_SUMMARY

      - name: Generate image artifact attestation
        uses: actions/attest-build-provenance@v1
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          subject-digest: ${{ steps.create.outputs.digest }}
          push-to-registry: true

      # Sign the resulting Docker image digest except on PRs.
      # This will only write to the public Rekor transparency log when the Docker
      # repository is public to avoid leaking data.  If you would like to publish
      # transparency data even for private images, pass --force to cosign below.
      # https://github.com/sigstore/cosign
      - name: Sign the published Docker image
        env:
          # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
          TAGS: ${{ steps.meta.outputs.tags }}
          DIGEST: ${{ steps.create.outputs.digest }}
        # This step uses the identity token to provision an ephemeral certificate
        # against the sigstore community Fulcio instance.
        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}

docker-simple.yml

# A workflow with a single Dockerfile that can be published multi-arch out of box

name: Publish Docker

on:
  push:
    branches: [ "master" ]
  pull_request:
    branches: [ "master" ]
  workflow_dispatch: {}

env:
  # Use docker.io for Docker Hub if empty
  REGISTRY: ghcr.io
  # github.repository as <account>/<repo>
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:

    runs-on: ubuntu-latest
    
    permissions:
      contents: read
      packages: write
      id-token: write
      attestations: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      # Install the cosign tool except on PR
      # https://github.com/sigstore/cosign-installer
      - name: Install cosign
        if: github.event_name != 'pull_request'
        uses: sigstore/cosign-installer@v3.5.0
        with:
          cosign-release: 'v2.2.4'

      # Set up BuildKit Docker container builder to be able to build
      # multi-platform images and export cache
      # https://github.com/docker/setup-buildx-action
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3.3.0

      # Login against a Docker registry except on PR
      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3.1.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Extract metadata (tags, labels) for Docker
      # https://github.com/docker/metadata-action
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5.5.1
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            # set latest tag for default branch
            type=raw,value=latest,enable={{is_default_branch}}
            type=ref,event=branch
            type=ref,event=tag
            type=sha

      # Build and push Docker image with Buildx (don't push on PR)
      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v5.3.0
        with:
          context: .
          #file: Dockerfile
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: linux/amd64,linux/arm64
          #cache-from: type=gha
          #cache-to: type=gha,mode=max

      - name: Print tags summary
        if: github.event_name != 'pull_request'
        run: |
          all_tags="${{ steps.meta.outputs.tags }}"
          echo -e "### Pushed:\n$(echo $all_tags | jq -Rrsc 'split(" ")[] | "- \(.)"')" >> $GITHUB_STEP_SUMMARY

      - name: Generate image artifact attestation
        if: github.event_name != 'pull_request'
        uses: actions/attest-build-provenance@v1
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          subject-digest: ${{ steps.build-and-push.outputs.digest }}
          push-to-registry: true

      # Sign the resulting Docker image digest except on PRs.
      # This will only write to the public Rekor transparency log when the Docker
      # repository is public to avoid leaking data.  If you would like to publish
      # transparency data even for private images, pass --force to cosign below.
      # https://github.com/sigstore/cosign
      - name: Sign the published Docker image
        if: github.event_name != 'pull_request'
        env:
          # https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-an-intermediate-environment-variable
          TAGS: ${{ steps.meta.outputs.tags }}
          DIGEST: ${{ steps.build-and-push.outputs.digest }}
        # This step uses the identity token to provision an ephemeral certificate
        # against the sigstore community Fulcio instance.
        run: echo "${TAGS}" | xargs -I {} cosign sign --yes {}@${DIGEST}