build-publish-docker.yml

# borrowed from
# https://github.com/PrivacyDevel/nitter/blob/master/.github/workflows/build-publish-docker.yml
name: Build and Publish Docker

on:
  push:
    branches: ["master"]
    paths-ignore: ["README.md"]
  pull_request:
    branches: ["master"]
    paths-ignore: ["README.md"]

env:
  IMAGE_NAME: ${{ github.repository }}

permissions:
  contents: read
  packages: write

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: |
            ghcr.io/${{ env.IMAGE_NAME }}
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: linux/amd64
      - name: Export digest
        if: github.event_name != 'pull_request'
        run: |
          mkdir -p /tmp/digests
          digest="${{ steps.build-and-push.outputs.digest }}"
          touch "/tmp/digests/${digest#sha256:}"
      - name: Upload digest
        uses: actions/upload-artifact@v4
        if: github.event_name != 'pull_request'
        with:
          name: digests-amd64
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1
  
  build-arm:
    runs-on: buildjet-2vcpu-ubuntu-2204-arm
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Extract Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: |
            ghcr.io/${{ env.IMAGE_NAME }}
      - name: Build and push Docker image
        id: build-and-push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          platforms: linux/arm64
      - name: Export digest
        if: github.event_name != 'pull_request'
        run: |
          mkdir -p /tmp/digests
          digest="${{ steps.build-and-push.outputs.digest }}"
          touch "/tmp/digests/${digest#sha256:}"
      - name: Upload digest
        uses: actions/upload-artifact@v4
        if: github.event_name != 'pull_request'
        with:
          name: digests-arm64
          path: /tmp/digests/*
          if-no-files-found: error
          retention-days: 1

  merge:
    runs-on: ubuntu-latest
    needs:
      - build
      - build-arm
    if: github.event_name != 'pull_request'
    steps:
      - name: Download digests
        uses: actions/download-artifact@v4
        with:
          path: /tmp/digests
          pattern: digests-*
          merge-multiple: true
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      - name: Docker meta
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ghcr.io/${{ github.repository }}
      - name: Log in to the Github Container registry
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Create manifest list and push
        working-directory: /tmp/digests
        run: |
          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
            $(printf 'ghcr.io/${{ github.repository }}@sha256:%s ' *)

  notify:
    runs-on: ubuntu-latest
    needs: merge
    if: github.event_name != 'pull_request'
    steps:
      - name: Send a Discord notification
        uses: nobrayner/discord-webhook@v1
        with:
          github-token: ${{ secrets.github_token }}
          discord-webhook: ${{ secrets.DISCORD_WEBHOOK }}