build.yml

name: Build and publish image to ghcr.io/epics-containers

on:
  push:
  pull_request:

jobs:
  build:
    # pull requests are a duplicate of a branch push if within the same repo.
    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
    permissions:
      contents: read
      packages: write
    strategy:
      fail-fast: true
      max-parallel: 1 # take advantage of caching
      matrix:
        target: [developer, runtime]
        include:
          - os: ubuntu-latest
            platforms: linux/amd64

    runs-on: ${{ matrix.os }}
    env:
      TAG: ghcr.io/${{ github.repository_owner }}/${{ github.event.repository.name }}-${{ matrix.target }}
    steps:

      - name: Log in to GitHub Docker Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io/${{ github.repository_owner }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Build image
        uses: docker/build-push-action@v5
        with:
          target: ${{ matrix.target }}
          tags: ${{ env.TAG }}:${{ github.ref_name }},${{ env.TAG }}:latest
          cache-from: type=gha
          cache-to: type=gha,mode=max
          load: true

      - name: Test image
        run: echo 'no tests yet'

      - name: Push image
        if: ${{ github.event_name == 'push' && github.ref_type == 'tag' }}
        uses: docker/build-push-action@v5
        with:
          tags: ${{ env.TAG }}:${{ github.ref_name }},${{ env.TAG }}:latest
          push: true