ci.yml

name: CI

on: [push, pull_request]

permissions:
  contents: read

jobs:
  build:
    name: Build (CMake) on ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-22.04, ubuntu-24.04]
    env:
      CMAKE_C_COMPILER_LAUNCHER: ccache
      CMAKE_CXX_COMPILER_LAUNCHER: ccache
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          submodules: recursive

      - name: Setup ccache
        uses: hendrikmuhs/ccache-action@v1
        with:
          max-size: 250M

      - name: Configure (CMake)
        run: cmake -S . -B build -DCMAKE_INSTALL_PREFIX=$HOME/.local

      - name: Build
        run: cmake --build build -j"$(nproc)"

      - name: Install
        run: cmake --install build

  docker:
    name: Build and push Docker image to GHCR
    # Always build image; push and attest only on default branch or tags
    needs: build
    runs-on: ubuntu-24.04
    permissions:
      contents: read
      packages: write
      id-token: write
      attestations: write
    env:
      REGISTRY: ghcr.io
      IMAGE_NAME: ${{ github.repository }}
      PLATFORMS: linux/amd64,linux/arm64
    steps:
      - name: Checkout
        uses: actions/checkout@v5
        with:
          fetch-depth: 0

      - name: Determine if we should push
        id: should_push
        run: |
          should_push="${{ github.event_name == 'push' && (startsWith(github.ref, 'refs/tags/') || github.ref == format('refs/heads/{0}', github.event.repository.default_branch)) }}"
          if [ "$should_push" = "true" ]; then
            echo "push=true" >> "$GITHUB_OUTPUT"
          else
            echo "push=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Compute platforms
        id: platforms
        run: |
          if [ "${{ steps.should_push.outputs.push }}" = "true" ]; then
            echo "value=${{ env.PLATFORMS }}" >> "$GITHUB_OUTPUT"
          else
            echo "value=linux/amd64" >> "$GITHUB_OUTPUT"
          fi

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3
        with:
          platforms: ${{ steps.platforms.outputs.value }}

      - name: Set up Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v3
        with:
          platforms: ${{ steps.platforms.outputs.value }}

      - name: Log in to the Container registry
        if: ${{ steps.should_push.outputs.push == 'true' }}
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: |
            ghcr.io/${{ github.repository }}
          tags: |
            type=ref,event=branch
            type=ref,event=tag
            type=sha
            type=raw,value=latest,enable={{is_default_branch}}

      - name: Build Docker image (push on default branch or tags)
        id: push
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: ${{ steps.buildx.outputs.platforms }}
          push: ${{ steps.should_push.outputs.push == 'true' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          load: ${{ steps.should_push.outputs.push != 'true' }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Generate artifact attestation
        if: ${{ steps.should_push.outputs.push == 'true' }}
        uses: actions/attest-build-provenance@v3
        with:
          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          subject-digest: ${{ steps.push.outputs.digest }}
          push-to-registry: true