pr.yml

name: Pull Request Pipeline

on:
  pull_request:
    branches:
      - main

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}-fluent-bit
  BUILD_PATH: podman/fluent-bit

jobs:
  # https://github.community/t/run-job-only-if-folder-changed/118292
  build-checks:
    outputs:
      build: ${{ steps.check.outputs.build }}
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v2
        with:
          # https://github.com/actions/checkout
          fetch-depth: 2

      - name: Check and process modified files
        id: check
        run: |
          # Check git diff against build path
          while read -r filename
          do
            if [[ $filename == ${{ env.BUILD_PATH }}/* ]]
            then
              echo "$filename --> triggering build"
              echo "::set-output name=build::true"
              break
            fi
          done < <(git diff --name-only)

  build-and-push-image:
    needs: build-checks
    if: needs.build-checks.outputs.build == 'true'
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      # https://github.com/marketplace/actions/docker-login#github-container-registry
      - name: Login to GitHub Container Registry
        uses: docker/login-action@v1.10.0
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # https://github.com/marketplace/actions/docker-metadata-action
      - name: Extract metadata (tags, labels) for Docker
        id: meta
        uses: docker/metadata-action@v3.5.0
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}

      # https://github.com/marketplace/actions/build-and-push-docker-images
      - name: Build and push Docker image
        uses: docker/build-push-action@v2.7.0
        with:
          context: ${{ env.BUILD_PATH }}
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}