build-actions-runner-images.yaml

name: Build Actions Runner Images
on:
  push:
    branches:
      - main
    paths:
      - apps/arc/runners/**/Dockerfile
  schedule:
    - cron: "0 0 * * 0"
  workflow_dispatch:

env:
  REGISTRY: ghcr.io

jobs:
  gather-dockerfiles:
    name: Gather Dockerfiles
    runs-on: pi-cluster
    outputs:
      contexts: ${{ github.event_name == 'push' && steps.find-changed.outputs.all_changed_files || steps.find-all.outputs.contexts }}
    steps:
      - name: Install tools
        run: |
          sudo apt update && sudo apt install -y git jq

      - name: Checkout
        uses: actions/checkout@v4

      - name: Find all changed Dockerfiles (push)
        id: find-changed
        if: github.event_name == 'push'
        uses: tj-actions/changed-files@v44
        with:
          files: apps/arc/runners/**/Dockerfile
          since_last_remote_commit: true
          json: true
          escape_json: false
          dir_names: true

      - name: Find all Dockerfiles (schedule)
        id: find-all
        if: github.event_name != 'push'
        run: |
          CONTEXTS=$(find apps/arc/runners \
            -name Dockerfile -printf '%h\n' | \
            jq -R -s -c 'split("\n")[:-1]')

          echo "contexts=${CONTEXTS}" >> "${GITHUB_OUTPUT}"

  build-image:
    name: Build Image
    runs-on: pi-cluster
    needs:
      - gather-dockerfiles
    permissions:
      contents: read
      packages: write
    strategy:
      matrix:
        context: ${{ fromJSON(needs.gather-dockerfiles.outputs.contexts) }}
    concurrency:
      group: build-image-${{ matrix.context }}
      cancel-in-progress: true
    steps:
      - name: Checkout
        uses: actions/checkout@9bb56186c3b09b4f86b1c65136769dd318469633 # v4

      - name: Build image name
        id: image-name
        env:
          context: ${{ matrix.context }}
        run: |
          echo "name=${context#apps/arc/runners/}" >> "${GITHUB_OUTPUT}"

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

      - name: Docker login
        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin

      - name: Build and push
        uses: docker/build-push-action@v5
        with:
          context: ${{ matrix.context }}
          push: true
          tags: ${{ env.REGISTRY }}/invakid404/runners/${{ steps.image-name.outputs.name }}:latest
          cache-from: type=gha
          cache-to: type=gha,mode=max