build.yml

---
# Single-job sequential build: base + K3s share local containers-storage so
# the K3s `FROM ${BASE_IMAGE}` resolves without a registry round-trip. This
# shape is the right answer for 2 images with a parent-child relationship.
#
# When you add a third leaf flavor (RKE2, MicroK8s, multi-arch, alternate
# kernel streams, …), refactor to two jobs:
#   1) build_base  (one runner, pushes by digest)
#   2) build_variants  (matrix over flavors, pins base by @digest)
# Full copy-paste-ready recipe + pitfalls:
#   docs/ci-build-matrix-refactor.md
name: Build container image
on:
  pull_request:
    branches:
      - main
  schedule:
    - cron: '05 10 * * *'  # 10:05am UTC everyday
  push:
    branches:
      - main
    paths-ignore:
      - '**/README.md'
  workflow_dispatch:

env:
  IMAGE_DESC: "My Customized Universal Blue Image"
  IMAGE_KEYWORDS: "bootc,ublue,universal-blue"
  IMAGE_LOGO_URL: "https://avatars.githubusercontent.com/u/120078124?s=200&v=4"  # Put your own image here for a fancy profile on https://artifacthub.io/!
  IMAGE_NAME: "${{ github.event.repository.name }}"  # output image name, usually same as repo name
  IMAGE_REGISTRY: "ghcr.io/${{ github.repository_owner }}"  # do not edit
  DEFAULT_TAG: "stable"

concurrency:
  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
  cancel-in-progress: true

jobs:
  build_push:
    name: Build and push image
    runs-on: ubuntu-24.04

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

    steps:
      - name: Prepare environment
        run: |
          # Lowercase the image uri
          echo "IMAGE_REGISTRY=${IMAGE_REGISTRY,,}" >> ${GITHUB_ENV}
          echo "IMAGE_NAME=${IMAGE_NAME,,}" >> ${GITHUB_ENV}

      # These stage versions are pinned by https://github.com/renovatebot/renovate
      - name: Checkout
        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5

      # This is optional, but if you see that your builds are way too big for the runners, you can enable this by uncommenting the following lines:
      # - name: Maximize build space
      #   uses: ublue-os/remove-unwanted-software@517622d6452028f266b7ba4cc9a123b5f58a6b53 # v7
      #   with:
      #     remove-codeql: true

      - name: Mount BTRFS for podman storage
        id: container-storage-action
        uses: ublue-os/container-storage-action@911baca08baf30c8654933e9e9723cb399892140 # main

        # Fallback to the remove-unwanted-software-action if github doesn't allocate enough space
        # See: https://github.com/ublue-os/container-storage-action/pull/11
        continue-on-error: true 
        with:
          target-dir: /var/lib/containers
          mount-opts: compress-force=zstd:2

      - name: Get current date
        id: date
        run: |
          # This generates a timestamp like what is defined on the ArtifactHub documentation
          # E.G: 2022-02-08T15:38:15Z'
          # https://artifacthub.io/docs/topics/repositories/container-images/
          # https://linux.die.net/man/1/date
          echo "date=$(date -u +%Y\-%m\-%d\T%H\:%M\:%S\Z)" >> $GITHUB_OUTPUT

      # Image metadata for https://artifacthub.io/ - This is optional but is highly recommended so we all can get a index of all the custom images
      # The metadata by itself is not going to do anything, you choose if you want your image to be on ArtifactHub or not.
      - name: Image Metadata (base)
        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5
        id: metadata
        with:
          # This generates all the tags for your image, you can add custom tags here too!
          # Default tags are "$DEFAULT_TAG" and "$DEFAULT_TAG.$date".
          tags: |
            type=raw,value=${{ env.DEFAULT_TAG }}
            type=raw,value=${{ env.DEFAULT_TAG }}.{{date 'YYYYMMDD'}}
            type=raw,value={{date 'YYYYMMDD'}}
            type=sha,enable=${{ github.event_name == 'pull_request' }}
            type=ref,event=pr
          labels: |
            io.artifacthub.package.readme-url=https://raw.githubusercontent.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/${{ github.sha }}/README.md
            org.opencontainers.image.created=${{ steps.date.outputs.date }}
            org.opencontainers.image.description=${{ env.IMAGE_DESC }}
            org.opencontainers.image.documentation=https://raw.githubusercontent.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/${{ github.sha }}/README.md
            org.opencontainers.image.source=https://github.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/blob/${{ github.sha }}/Containerfile
            org.opencontainers.image.title=${{ env.IMAGE_NAME }}
            org.opencontainers.image.url=https://github.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/tree/${{ github.sha }}
            org.opencontainers.image.vendor=${{ github.repository_owner }}
            org.opencontainers.image.version=${{ env.DEFAULT_TAG }}.{{date 'YYYYMMDD'}}
            io.artifacthub.package.deprecated=false
            io.artifacthub.package.keywords=${{ env.IMAGE_KEYWORDS }}
            io.artifacthub.package.license=Apache-2.0
            io.artifacthub.package.logo-url=${{ env.IMAGE_LOGO_URL }}
            io.artifacthub.package.prerelease=false
            containers.bootc=1
          sep-tags: " "
          sep-annotations: " "

      # Same shape as the base metadata, but with title/source/url pointing at
      # the K3s flavor so downstream tools (ArtifactHub, OCI inspectors,
      # `bootc status`) report the correct image identity.
      - name: Image Metadata (K3s)
        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5
        id: metadata_k3s
        with:
          tags: |
            type=raw,value=${{ env.DEFAULT_TAG }}
            type=raw,value=${{ env.DEFAULT_TAG }}.{{date 'YYYYMMDD'}}
            type=raw,value={{date 'YYYYMMDD'}}
            type=sha,enable=${{ github.event_name == 'pull_request' }}
            type=ref,event=pr
          labels: |
            io.artifacthub.package.readme-url=https://raw.githubusercontent.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/${{ github.sha }}/README.md
            org.opencontainers.image.created=${{ steps.date.outputs.date }}
            org.opencontainers.image.description=${{ env.IMAGE_DESC }} (K3s flavor)
            org.opencontainers.image.documentation=https://raw.githubusercontent.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/${{ github.sha }}/docs/k3s-rancher-vms.md
            org.opencontainers.image.source=https://github.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/blob/${{ github.sha }}/Containerfile.k3s
            org.opencontainers.image.title=${{ env.IMAGE_NAME }}-k3s
            org.opencontainers.image.url=https://github.com/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}/tree/${{ github.sha }}
            org.opencontainers.image.vendor=${{ github.repository_owner }}
            org.opencontainers.image.version=${{ env.DEFAULT_TAG }}.{{date 'YYYYMMDD'}}
            io.artifacthub.package.deprecated=false
            io.artifacthub.package.keywords=${{ env.IMAGE_KEYWORDS }},k3s,kubernetes
            io.artifacthub.package.license=Apache-2.0
            io.artifacthub.package.logo-url=${{ env.IMAGE_LOGO_URL }}
            io.artifacthub.package.prerelease=false
            containers.bootc=1
          sep-tags: " "
          sep-annotations: " "

      - name: Build Image
        id: build_image
        uses: redhat-actions/buildah-build@7a95fa7ee0f02d552a32753e7414641a04307056 # v2
        with:
          containerfiles: |
            ./Containerfile
          # Postfix image name with -custom to make it a little more descriptive
          # Syntax: https://docs.github.com/en/actions/learn-github-actions/expressions#format
          image: ${{ env.IMAGE_NAME }}
          tags: ${{ env.DEFAULT_TAG }}
          labels: ${{ steps.metadata.outputs.labels }}
          oci: false

      # Tag for registry
      - name: Tag for registry
        run: |
          for tag in ${{ steps.metadata.outputs.tags }}; do
            podman tag ${{ env.IMAGE_NAME }}:${{ env.DEFAULT_TAG }} ${{ env.IMAGE_NAME }}:$tag
          done

      # Build the K3s flavor on top of the freshly-built base. buildah picks
      # up `localhost/<image>:stable` from local containers-storage — no
      # registry round-trip needed. Containerfile.k3s honors BASE_IMAGE as
      # its FROM, so we just point at the local tag.
      - name: Build K3s flavor image
        id: build_image_k3s
        uses: redhat-actions/buildah-build@7a95fa7ee0f02d552a32753e7414641a04307056 # v2
        with:
          containerfiles: |
            ./Containerfile.k3s
          image: ${{ env.IMAGE_NAME }}-k3s
          tags: ${{ env.DEFAULT_TAG }}
          labels: ${{ steps.metadata_k3s.outputs.labels }}
          build-args: |
            BASE_IMAGE=localhost/${{ env.IMAGE_NAME }}:${{ env.DEFAULT_TAG }}
          oci: false

      - name: Tag K3s flavor for registry
        run: |
          for tag in ${{ steps.metadata.outputs.tags }}; do
            podman tag ${{ env.IMAGE_NAME }}-k3s:${{ env.DEFAULT_TAG }} ${{ env.IMAGE_NAME }}-k3s:$tag
          done

      # SBOM (OPTIONAL): Software Bill of Materials generation using Syft
      # Creates a detailed inventory of all software components in the image for supply chain security.
      # To enable:
      #   1. Uncomment the "Setup Syft" step below
      #   2. Uncomment the "Generate SBOM" step below
      #   3. If using image signing, also uncomment the "Add SBOM Attestation" step further down
      # Documentation: https://github.com/anchore/syft
      
      # - name: Setup Syft
      #   id: setup-syft
      #   uses: anchore/sbom-action/download-syft@8e94d75ddd33f69f691467e42275782e4bfefe84 # v0.20.9
      #   with:
      #     syft-version: v1.20.0
      #
      # - name: Generate SBOM
      #   id: generate-sbom
      #   env:
      #     IMAGE: ${{ env.IMAGE_NAME }}
      #     DEFAULT_TAG: ${{ env.DEFAULT_TAG }}
      #     SYFT_CMD: ${{ steps.setup-syft.outputs.cmd }}
      #   run: |
      #     OUTPUT_PATH="$(mktemp -d)/sbom.json"
      #     export SYFT_PARALLELISM=$(($(nproc)*2))
      #     $SYFT_CMD ${IMAGE}:${DEFAULT_TAG} -o spdx-json=${OUTPUT_PATH}
      #     echo "OUTPUT_PATH=${OUTPUT_PATH}" >> $GITHUB_OUTPUT

      # These `if` statements are so that pull requests for your custom images do not make it publish any packages under your name without you knowing
      # They also check if the runner is on the default branch so that things like the merge queue (if you enable it), are going to work
      - name: Login to GitHub Container Registry
        uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef # v3
        if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Push To GHCR (base)
        uses: redhat-actions/push-to-registry@5ed88d269cf581ea9ef6dd6806d01562096bee9c # v2
        if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
        id: push
        env:
          REGISTRY_USER: ${{ github.actor }}
          REGISTRY_PASSWORD: ${{ github.token }}
        with:
          registry: ${{ env.IMAGE_REGISTRY }}
          image: ${{ env.IMAGE_NAME }}
          tags: ${{ steps.metadata.outputs.tags }}
          username: ${{ env.REGISTRY_USER }}
          password: ${{ env.REGISTRY_PASSWORD }}

      - name: Push To GHCR (K3s flavor)
        uses: redhat-actions/push-to-registry@5ed88d269cf581ea9ef6dd6806d01562096bee9c # v2
        if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
        id: push_k3s
        env:
          REGISTRY_USER: ${{ github.actor }}
          REGISTRY_PASSWORD: ${{ github.token }}
        with:
          registry: ${{ env.IMAGE_REGISTRY }}
          image: ${{ env.IMAGE_NAME }}-k3s
          tags: ${{ steps.metadata.outputs.tags }}
          username: ${{ env.REGISTRY_USER }}
          password: ${{ env.REGISTRY_PASSWORD }}

      # Image signing with Cosign. Signs every tag of both flavors using the
      # repository's SIGNING_SECRET. The corresponding public key (cosign.pub)
      # is baked into the image by build/10-build.sh, so consumers verify these
      # signatures on `bootc upgrade`/`switch` by default — no per-VM setup.
      - name: Install Cosign
        uses: sigstore/cosign-installer@d7543c93d881b35a8faa02e8e3605f69b7a1ce62 # v3.10.0
        if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)

      - name: Sign container images
        if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
        env:
          COSIGN_EXPERIMENTAL: false
          COSIGN_PRIVATE_KEY: ${{ secrets.SIGNING_SECRET }}
        run: |
          for image in "${{ env.IMAGE_NAME }}" "${{ env.IMAGE_NAME }}-k3s"; do
            FULL="${{ env.IMAGE_REGISTRY }}/${image}"
            for tag in ${{ steps.metadata.outputs.tags }}; do
              echo ">>> cosign sign ${FULL}:${tag}"
              cosign sign -y --key env://COSIGN_PRIVATE_KEY "${FULL}:${tag}"
            done
          done

      # OPTIONAL: SBOM Attestation
      # Attaches SBOM (Software Bill of Materials) to your signed image for supply chain security.
      # Requires image signing to be enabled first (see above).
      # To enable:
      #   1. First enable image signing (see above section)
      #   2. Uncomment the "Add SBOM Attestation" step below
      # Documentation: https://slsa.dev/spec/v1.0/requirements#provenance-available

      # - name: Add SBOM Attestation
      #   if: github.event_name != 'pull_request' && github.ref == format('refs/heads/{0}', github.event.repository.default_branch)
      #   env:
      #     IMAGE: ${{ env.IMAGE_REGISTRY }}/${{ env.IMAGE_NAME }}
      #     DIGEST: ${{ steps.push.outputs.digest }}
      #     COSIGN_PRIVATE_KEY: ${{ secrets.SIGNING_SECRET }}
      #     SBOM_OUTPUT: ${{ steps.generate-sbom.outputs.OUTPUT_PATH }}
      #   run: |
      #     cd "$(dirname "$SBOM_OUTPUT")"
      #     cosign attest -y \
      #       --predicate "$(basename "$SBOM_OUTPUT")" \
      #       --type spdxjson \
      #       --key env://COSIGN_PRIVATE_KEY \
      #       "${IMAGE}@${DIGEST}"