update-docker-images.yml

name: Update Docker Images

on:
  schedule:
    - cron: "0 1 * * *"
  workflow_dispatch:

defaults:
  run:
    shell: bash

jobs:
  variables:
    name: Get version of base image
    runs-on: ubuntu-20.04
    outputs:
      versions: ${{ steps.version.outputs.matrix }}
      git_tag: ${{ steps.tag.outputs.git_tag }}
      docker_platforms: ${{ steps.vars.outputs.docker_platforms }}
    steps:
      - name: Checkout Repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Get latest tag
        id: tag
        run: |
          tag=$(git tag --sort=-version:refname | head -n1)
          echo "git_tag=${tag//v}" >> $GITHUB_OUTPUT
      - name: Checkout Repository at ${{ steps.tag.outputs.git_tag }}
        uses: actions/checkout@v4
        with:
          ref: refs/tags/v${{ steps.tag.outputs.git_tag }}
      - name: Set Base image version
        id: version
        run: |
          nginx_alpine=library/nginx:$(grep -m1 "FROM.*nginx.*alpine" <Dockerfile | awk -F"[ :]" '{print $3}')
          nginx=library/$(grep -m1 "FROM nginx:" < Dockerfile | awk -F" " '{print $2}')
          echo "matrix=[{\"version\": \"${nginx}\", \"distro\": \"debian\"}, {\"version\": \"${nginx_alpine}\", \"distro\": \"alpine\"}]" >> $GITHUB_OUTPUT
      - name: Set other variables
        id: vars
        run: |
          echo "docker_platforms=$(grep "PLATFORMS:" .github/workflows/docker.yml | awk -F" " '{print $2}')" >> $GITHUB_OUTPUT

  check:
    name: Check if updates are needed
    runs-on: ubuntu-20.04
    needs: variables
    outputs:
      needs-updating-debian: ${{ steps.var.outputs.debian }}
      needs-updating-alpine: ${{ steps.var.outputs.alpine }}
    strategy:
      matrix:
        base_image: ${{ fromJson(needs.variables.outputs.versions) }}
    steps:
      - name: Build image tag
        id: dist
        run: |
          if [ ${{ matrix.base_image.distro }} == "debian" ]; then dist=""; else dist="-${{ matrix.base_image.distro }}"; fi
          echo "tag=${{ needs.variables.outputs.git_tag }}${dist}" >> $GITHUB_OUTPUT
      - name: Check if update available ${{ matrix.base_image.version }}
        id: update
        uses: lucacome/docker-image-update-checker@v1
        with:
          base-image: ${{ matrix.base_image.version }}
          image: opentracing/nginx-opentracing:${{ steps.dist.outputs.tag }}
      - id: var
        run: |
          echo "${{ matrix.base_image.distro }}=${{ steps.update.outputs.needs-updating }}" >> $GITHUB_OUTPUT

  build-docker:
    if: ${{ needs.check.outputs.needs-updating-debian == 'true' || needs.check.outputs.needs-updating-alpine == 'true' }}
    name: Build Docker Image
    runs-on: ubuntu-20.04
    needs: [check, variables]
    strategy:
      matrix:
        include:
          - os: debian
            needs-updating: ${{ needs.check.outputs.needs-updating-debian }}
          - os: alpine
            needs-updating: ${{ needs.check.outputs.needs-updating-alpine }}
    steps:
      - name: Checkout Repository at ${{ needs.variables.outputs.git_tag }}
        uses: actions/checkout@v4
        with:
          ref: refs/tags/v${{ needs.variables.outputs.git_tag }}
        if: ${{ matrix.needs-updating == 'true' }}

      - name: Output Variables
        id: var
        run: |
          echo "nginx_version=$(grep -m1 'FROM nginx:' <Dockerfile | awk -F'[: ]' '{print $3}')" >> $GITHUB_OUTPUT
        if: ${{ matrix.needs-updating == 'true' }}

      - name: Setup QEMU
        uses: docker/setup-qemu-action@v3
        if: ${{ matrix.needs-updating == 'true' }}

      - name: Docker Buildx
        uses: docker/setup-buildx-action@v3
        if: ${{ matrix.needs-updating == 'true' }}

      - name: DockerHub Login
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}
        if: ${{ matrix.needs-updating == 'true' }}

      - name: Login to GitHub Container Registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}
        if: ${{ matrix.needs-updating == 'true' }}

      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v5
        with:
          context: git
          images: |
            opentracing/nginx-opentracing
            ghcr.io/opentracing-contrib/nginx-opentracing
          flavor: |
            latest=true
            suffix=${{ matrix.os != 'debian' && '-' || '' }}${{ matrix.os != 'debian' && matrix.os || '' }},onlatest=true
          tags: |
            type=raw,value=${{ needs.variables.outputs.git_tag }}
            type=raw,value=nginx-${{ steps.var.outputs.nginx_version }}
        if: ${{ matrix.needs-updating == 'true' }}

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          pull: true
          push: true
          platforms: ${{ needs.variables.outputs.docker_platforms }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha,scope=${{ matrix.os }}
          cache-to: type=gha,scope=${{ matrix.os }},mode=max
          target: final
          build-args: BUILD_OS=${{ matrix.os }}
        if: ${{ matrix.needs-updating == 'true' }}