build.yml

on:
  push: {}
  workflow_dispatch: {}

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

jobs:
  build:
    runs-on: ubuntu-22.04
    steps:
      # Checkout push-to-registry action GitHub repository
      - name: Checkout Push to Registry action
        uses: actions/checkout@v4

      - name: Generate tags
        id: generate-tags
        shell: bash
        run: |
          # Generate a timestamp for creating an image version history
          TIMESTAMP="$(date +%Y%m%d)"
          COREOS_VERSION="stable"
          BRANCH="${GITHUB_REF#refs/heads/}"

          COMMIT_TAGS=()
          BRANCH_TAGS=()
          BUILD_TAGS=()

          # Have tags for tracking builds during pull request
          SHA_SHORT="${GITHUB_SHA::7}"
          COMMIT_TAGS+=("pr-${{ github.event.number }}-${COREOS_VERSION}")
          COMMIT_TAGS+=("${SHA_SHORT}-${COREOS_VERSION}")

          BRANCH_TAGS+=("${COREOS_VERSION}-${BRANCH}")

          BUILD_TAGS=("${COREOS_VERSION}" "${COREOS_VERSION}-${TIMESTAMP}")

          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[@]}")

          elif [[ "${BRANCH}" != "main" ]]; then
              echo "Generated the following branch tags: "
              for TAG in "${BRANCH_TAGS[@]}"; do
                  echo "${TAG}"
              done

              alias_tags=("${BRANCH_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: |
            corehost
          labels: |
            io.artifacthub.package.logo-url=https://avatars.githubusercontent.com/u/120078124?s=200&v=4
            io.artifacthub.package.readme-url=https://raw.githubusercontent.com/ublue-os/ucore/main/README.md
            org.opencontainers.image.description=An OCI image of Fedora CoreOS
            org.opencontainers.image.title=corehost
            org.opencontainers.image.version=corehost

      # Build image using Buildah action
      - name: Build Image
        id: build_image
        uses: redhat-actions/buildah-build@v2
        with:
          containerfiles: |
            ./Containerfile
          context: .
          image: corehost
          tags: |
            ${{ steps.generate-tags.outputs.alias_tags }}
          build-args: |
            COREOS_VERSION=stable
          labels: ${{ steps.meta.outputs.labels }}
          oci: false

      # Workaround bug where capital letters in your GitHub username make it impossible to push to GHCR.
      # https://github.com/macbre/push-to-ghcr/issues/12
      - name: Lowercase Registry
        id: registry_case
        uses: ASzc/change-string-case-action@v6
        with:
          string: ghcr.io/${{ github.repository }}

      # 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'
        env:
          REGISTRY_USER: ${{ github.actor }}
          REGISTRY_PASSWORD: ${{ github.token }}
        with:
          image: ${{ steps.build_image.outputs.image }}
          tags: ${{ steps.build_image.outputs.tags }}
          registry: ${{ steps.registry_case.outputs.lowercase }}
          username: ${{ env.REGISTRY_USER }}
          password: ${{ env.REGISTRY_PASSWORD }}
          extra-args: |
            --disable-content-trust

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v3
        if: github.event_name != 'pull_request'
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # Sign container
      - uses: sigstore/cosign-installer@v3.3.0
        if: github.event_name != 'pull_request'

      - name: Sign container image
        if: github.event_name != 'pull_request'
        run: |
          cosign sign -y --key env://COSIGN_PRIVATE_KEY ${{ steps.registry_case.outputs.lowercase }}/${{ steps.build_image.outputs.image }}@${TAGS}
        env:
          TAGS: ${{ steps.push.outputs.digest }}
          COSIGN_EXPERIMENTAL: false
          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}

      - name: Echo outputs
        if: github.event_name != 'pull_request'
        run: |
          echo "${{ toJSON(steps.push.outputs) }}"