ci+cd.yaml

name: CI/CD - Push Image & Update Manifests

# https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax\#onpushpull_requestpull_request_targetpathspaths-ignore
# https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax\#onworkflow_dispatch
on:
  push:
    branches: ["main"]
    # Skip this workflow when only K8s manifest files change, since
    # such changes don’t require rebuilding the whole application.
    # Argo CD picks them up automatically.
    paths:
      - "app/**"
      - "**/Dockerfile*"
      - ".github/workflows/**"
  workflow_dispatch:

# https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax\#env
env:
  # Use GitHub Container registry (GHCR).
  REGISTRY: ghcr.io

# https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax\#jobs
jobs:
  ci:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    outputs:
      tags: ${{ steps.meta.outputs.tags }}

    steps:
      # https://github.com/actions/checkout
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 1

      # https://github.com/docker/setup-buildx-action
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      # https://github.com/docker/login-action
      - name: Log into registry ${{ env.REGISTRY }}
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          # https://docs.github.com/en/actions/tutorials/authenticate-with-github_token
          password: ${{ secrets.GITHUB_TOKEN }}

      # https://github.com/docker/metadata-action
      - name: Define image metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: |
            ${{ env.REGISTRY }}/${{ github.repository }}
          # While preprocessing, tags are sorted based on its priority (from high to low).
          # https://github.com/docker/metadata-action\#priority-attribute
          tags: |
            type=raw,value=latest,priority=200
            type=sha,prefix=sha-,priority=100
        env:
          # https://github.com/docker/metadata-action\#typesha
          DOCKER_METADATA_SHORT_SHA_LENGTH: 12

      # https://github.com/docker/build-push-action
      - name: Build and push Docker image
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          # https://github.com/moby/buildkit\#github-actions-cache-experimental
          cache-from: type=gha
          cache-to: type=gha,mode=max
  cd:
    needs: ci
    runs-on: ubuntu-latest
    permissions:
      contents: write

    steps:
      # https://github.com/actions/checkout
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 1

      # https://github.com/mikefarah/yq
      - name: Install yq
        run: |
          VERSION=v4.43.1
          wget "https://github.com/mikefarah/yq/releases/download/${VERSION}/yq_linux_amd64" -O /usr/local/bin/yq
          chmod +x /usr/local/bin/yq

      - name: Patch kubernetes manifest with image tag
        id: patch
        run: |
          export IMG_SHA_REF=$(echo -n "${{ needs.ci.outputs.tags }}" | tail -n 1)
          echo "img-sha-ref=$IMG_SHA_REF" >> $GITHUB_OUTPUT
          yq e '.spec.template.spec.containers[0].image = strenv(IMG_SHA_REF)' -i manifests/deployment.yaml

      - name: Commit and push manifest update
        # https://docs.github.com/en/actions/how-tos/manage-workflow-runs/skip-workflow-runs
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git commit -a -F - <<'EOF' || echo "No changes to commit"
          chore(cd): [skip ci] update manifests

          Used image: ${{ steps.patch.outputs.img-sha-ref }}
          EOF
          git push