docs/.github/workflows/docker-publish.yml

name: Build and Push Container Image
description: Build and push a container image based on the input arguments provided

"on":
  workflow_call:
    inputs:
      image_name:
        type: string
        required: true
        description: The suffix for the image name, without the registry and without the repository path.
      context:
        type: string
        required: true
        description: The path to the context to start `docker build` into.
      target:
        type: string
        required: false
        default: ""
        description: The Dockerfile target stage to build the image for.
      should_push:
        type: boolean
        required: false
        default: false
        description: if the image should be pushed on the docker registry
      docker_user:
        type: string
        required: false
        default: ""
        description: The docker_user ARGUMENT to pass to the build step
      arm64_reuse_amd64_build_arg:
        type: string
        required: false
        default: ""
        description: "Build arg name to pass first amd64 tag to arm64 build (skips arch-independent build steps)"

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      - name: Login to DockerHub
        if: ${{ inputs.should_push }}
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_HUB_USER }}
          password: ${{ secrets.DOCKER_HUB_PASSWORD }}
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ inputs.image_name }}
      - name: Generate platform-specific tags
        id: platform-tags
        run: |
          AMD64_TAGS=$(echo "${{ steps.meta.outputs.tags }}" | sed 's/$/-amd64/')
          ARM64_TAGS=$(echo "${{ steps.meta.outputs.tags }}" | sed 's/$/-arm64/')
          FIRST_AMD64_TAG=$(echo "${{ steps.meta.outputs.tags }}" | head -1)-amd64
          {
            echo "amd64<<EOF"
            echo "$AMD64_TAGS"
            echo "EOF"
            echo "arm64<<EOF"
            echo "$ARM64_TAGS"
            echo "EOF"
            echo "amd64_first=$FIRST_AMD64_TAG"
          } >> "$GITHUB_OUTPUT"
      # - name: Run trivy scan
      #   if: vars.TRIVY_SCAN_ENABLED
      #   uses: numerique-gouv/action-trivy-cache@main
      #   with:
      #     docker-build-args: "--target backend-production -f Dockerfile"
      #     docker-image-name: "docker.io/${{ inputs.image_name }}:${{ github.sha }}"
      #     trivyignores: ./.github/.trivyignore
      - name: Build and push (amd64)
        uses: docker/build-push-action@v6
        with:
          context: ${{ inputs.context }}
          target: ${{ inputs.target }}
          platforms: linux/amd64
          build-args: |
            DOCKER_USER=${{ inputs.docker_user }}
          push: ${{ inputs.should_push }}
          provenance: false
          tags: ${{ steps.platform-tags.outputs.amd64 }}
          labels: ${{ steps.meta.outputs.labels }}
      - name: Build and push (arm64)
        if: ${{ inputs.should_push }}
        uses: docker/build-push-action@v6
        with:
          context: ${{ inputs.context }}
          target: ${{ inputs.target }}
          platforms: linux/arm64
          build-args: |
            DOCKER_USER=${{ inputs.docker_user }}
            ${{ inputs.arm64_reuse_amd64_build_arg && format('{0}={1}', inputs.arm64_reuse_amd64_build_arg, steps.platform-tags.outputs.amd64_first) || '' }}
          push: ${{ inputs.should_push }}
          provenance: false
          tags: ${{ steps.platform-tags.outputs.arm64 }}
          labels: ${{ steps.meta.outputs.labels }}
      - name: Create multi-arch manifests
        if: ${{ inputs.should_push }}
        id: create-manifest
        run: |
          IMAGE="${{ inputs.image_name }}"
          readarray -t TAGS <<< "${{ steps.meta.outputs.tags }}"
          FIRST_TAG=""
          for tag in "${TAGS[@]}"; do
            [ -z "$tag" ] && continue
            docker buildx imagetools create -t "$tag" \
              "${tag}-amd64" "${tag}-arm64"
            if [ -z "$FIRST_TAG" ]; then
              FIRST_TAG="$tag"
            fi
          done
          # Get the digest of the multi-arch manifest for attestation
          # Note: --format '{{.Manifest.Digest}}' is broken (docker/buildx#1175),
          # so we compute it from the raw manifest JSON instead.
          if [ -n "$FIRST_TAG" ]; then
            DIGEST="sha256:$(docker buildx imagetools inspect "$FIRST_TAG" --raw | sha256sum | awk '{print $1}')"
            echo "digest=$DIGEST" >> "$GITHUB_OUTPUT"
          fi
      - name: Cleanup Docker after build
        if: always()
        run: |
          docker system prune -af
          docker volume prune -f