name: Build backend images

# Builds all 7 V2 microservice images with BuildKit + GitHub Actions layer cache.
# Cache is scoped per service, so each image only re-runs the steps that changed:
#   - .NET services skip `dotnet restore` unless a .csproj changes
#   - Go services skip nothing network-bound (deps are vendored) and reuse compile cache
on:
  push:
    branches: [master, main]
    paths:
      - "services/**"
      - ".github/workflows/build.yml"
  pull_request:
    paths:
      - "services/**"
      - ".github/workflows/build.yml"
  workflow_dispatch:

jobs:
  build:
    name: build ${{ matrix.service.name }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        service:
          - { name: identity-svc,     context: ./services/identity }
          - { name: content-svc,      context: ./services/content }
          - { name: studio-svc,       context: ./services/studio }
          - { name: file-svc,         context: ./services/file }
          - { name: render-svc,       context: ./services/render }
          - { name: notification-svc, context: ./services/notification }
          - { name: gateway,          context: ./services/gateway }
    steps:
      - name: Checkout
        uses: actions/checkout@v4

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

      - name: Build ${{ matrix.service.name }}
        uses: docker/build-push-action@v6
        with:
          context: ${{ matrix.service.context }}
          file: ${{ matrix.service.context }}/Dockerfile
          push: false
          load: false
          # GitHub Actions cache backend — persists layers across CI runs.
          # `scope` keeps each service's cache isolated so they don't evict each other.
          cache-from: type=gha,scope=${{ matrix.service.name }}
          cache-to: type=gha,scope=${{ matrix.service.name }},mode=max
          tags: flatrender2-${{ matrix.service.name }}:ci