build.yml

name: build
on: # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows
  push:
    branches:
      - main
    paths-ignore: # don't rebuild if only documentation has changed
      - "**.md"
  pull_request:
  workflow_dispatch:

# Only deploys the branch named "live". Ignores all other branches, to allow
# having "development" branches without interfering with GHCR image uploads.
jobs:
  push-ghcr:
    name: Build and push image
    runs-on: ubuntu-22.04
    permissions:
      contents: read
      packages: write
      id-token: write
    strategy:
      fail-fast: false
      matrix:
        arch: [amd64, arm64]

    steps:
      - name: Maximize build space
        uses: AdityaGarg8/remove-unwanted-software@v1
        with:
          remove-dotnet: 'true'
          remove-android: 'true'
          remove-haskell: 'true'

      # Checkout push-to-registry action GitHub repository
      - name: Checkout Push to Registry action
        uses: actions/checkout@v4

      - name: Install cosign
        if: github.event_name != 'pull_request' && github.ref == 'refs/heads/live'
        uses: sigstore/cosign-installer@v3.3.0

      - name: Add yq (for reading desc.yml)
        uses: mikefarah/yq@v4.35.1

      # important here is to lowercase image related variables like IMAGE_REGISTRY
      # and IMAGE_NAME because docker does not allow uppercase chars in the whole image name.

      - name: Gather image data from description
        run: |
          echo "IMAGE_TITLE=$(yq '.title' ./desc.yml)" >> $GITHUB_ENV
          echo "IMAGE_NAME=${GITHUB_REPOSITORY_OWNER@L}/$(yq '.name | downcase' ./desc.yml)" >> $GITHUB_ENV
          echo "IMAGE_DESCRIPTION=$(yq '.description' ./desc.yml)" >> $GITHUB_ENV
          echo "IMAGE_MAJOR_VERSION=$(yq '.image-version' ./desc.yml)" >> $GITHUB_ENV
          echo "IMAGE_REGISTRY=$(yq '.image-registry | downcase' ./desc.yml)" >> GITHUB_ENV

      - name: Generate tags
        id: generate-tags
        shell: bash
        run: |
          # Generate a timestamp for creating an image version history
          TIMESTAMP="$(date +%Y%m%d)"
          MAJOR_VERSION="${IMAGE_MAJOR_VERSION}"
          COMMIT_TAGS=()
          BUILD_TAGS=()
          # Have tags for tracking builds during pull request
          SHA_SHORT="${GITHUB_SHA::7}"

          # Using clever bash string templating, https://stackoverflow.com/q/40771781
          # don't make malformed tags if $MAJOR_VERSION is empty (base-image didn't include proper labels) --
          COMMIT_TAGS+=("pr-${{ github.event.number }}${MAJOR_VERSION:+-$MAJOR_VERSION}-${{ matrix.arch }}")
          COMMIT_TAGS+=("${SHA_SHORT}${MAJOR_VERSION:+-$MAJOR_VERSION}-${{ matrix.arch }}")

          BUILD_TAGS=("${MAJOR_VERSION}-${{ matrix.arch }}" "${MAJOR_VERSION:+$MAJOR_VERSION-}${TIMESTAMP}-${{ matrix.arch }}")
          # --

          BUILD_TAGS+=("${TIMESTAMP}-${{ matrix.arch }}")
          BUILD_TAGS+=("latest-${{ matrix.arch }}")

          if [[ "${{ github.event_name }}" == "pull_request" ]]; then
              echo "Generated the following commit tags: "
              for TAG in "${COMMIT_TAGS[@]}"; do
                  echo "${TAG}"
              done
              alias_tags=("${COMMIT_TAGS[@]}")
          else
              alias_tags=("${BUILD_TAGS[@]}")
          fi
          echo "Generated the following build tags: "
          for TAG in "${BUILD_TAGS[@]}"; do
              echo "${TAG}"
          done
          echo "alias_tags=${alias_tags[*]}" >> $GITHUB_OUTPUT

      # Build metadata
      - name: Image Metadata
        uses: docker/metadata-action@v5
        id: meta
        with:
          images: |
            ${{ env.IMAGE_NAME }}
          labels: |
            org.opencontainers.image.title=${{ env.IMAGE_TITLE }}
            org.opencontainers.image.ref.name=${{ env.IMAGE_NAME }}
            org.opencontainers.image.version=${{ env.IMAGE_MAJOR_VERSION }}
            org.opencontainers.image.description=${{ env.IMAGE_DESCRIPTION }}
            io.artifacthub.package.readme-url=https://raw.githubusercontent.com/drakulix/infinity/main/README.md
            io.artifacthub.package.logo-url=https://avatars.githubusercontent.com/u/33131755?s=200&v=4
      
      - name: Install qemu dependency
        run: |
          sudo apt-get update
          sudo apt-get install -y qemu-user-static

      # Build image using Buildah action
      - name: Build Image
        id: build_image
        uses: redhat-actions/buildah-build@v2
        with:
          containerfiles: |
            ./Containerfile
          image: ${{ env.IMAGE_NAME }}
          tags: |
            ${{ steps.generate-tags.outputs.alias_tags }}
          archs: ${{ matrix.arch }}
          build-args: |
            IMAGE_MAJOR_VERSION=${{ env.IMAGE_MAJOR_VERSION }}
          labels: ${{ steps.meta.outputs.labels }}
          oci: false
      - name: Login to GitHub Container Registry
        uses: docker/login-action@v3
        if: github.event_name != 'pull_request' && github.ref == 'refs/heads/live'
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Push the image to GHCR (Image Registry)
      - name: Push To GHCR
        uses: redhat-actions/push-to-registry@v2
        id: push
        if: github.event_name != 'pull_request' && github.ref == 'refs/heads/live'
        with:
          image: ${{ steps.build_image.outputs.image }}
          tags: ${{ steps.build_image.outputs.tags }}
          registry: ${{ env.IMAGE_REGISTRY }}
          username: ${{ env.REGISTRY_USER }}
          password: ${{ env.REGISTRY_PASSWORD }}

      - name: Echo outputs
        if: github.event_name != 'pull_request' && github.ref == 'refs/heads/live'
        run: |
          echo "${{ toJSON(steps.push.outputs) }}"
          
      # 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' && github.ref == 'refs/heads/live'
        env:
          COSIGN_EXPERIMENTAL: "true"
        # This step uses the identity token to provision an ephemeral certificate
        # against the sigstore community Fulcio instance.
        run: cosign sign --yes ${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}@${{ steps.push.outputs.digest }}