docker-publish.yml

name: Publish Docker image to GHCR

# Builds the image on GitHub's runners and pushes it to ghcr.io.
#
# This exists because pushing from a laptop needs a Personal Access Token with
# `write:packages`. Actions gets an automatic GITHUB_TOKEN that already has it —
# see `permissions:` below — so nobody has to create or store a PAT.

on:
  push:
    tags: ["v*"]          # every release tag publishes a matching image
  workflow_dispatch:       # ...and you can run it by hand from the Actions tab

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write      # this is what replaces the PAT

    steps:
      # The image is ~11GB. A stock runner has ~14GB free on /, which is not
      # enough, so reclaim the preinstalled toolchains we don't use first.
      - name: Free up disk space
        run: |
          echo "before:"; df -h / | tail -1
          sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc \
                      /usr/local/share/boost /usr/local/lib/node_modules \
                      /opt/hostedtoolcache/CodeQL "$AGENT_TOOLSDIRECTORY" || true
          sudo apt-get clean
          docker image prune -af || true
          echo "after:"; df -h / | tail -1

      - uses: actions/checkout@v4

      - uses: docker/setup-buildx-action@v3

      - name: Log in to GHCR
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=tag
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=raw,value=latest,enable={{is_default_branch}}
            type=raw,value=latest,enable=${{ startsWith(github.ref, 'refs/tags/v') }}

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          # linux/amd64 only: this image installs nine projects, and emulating
          # arm64 under QEMU pushes the build past the runner's time limit.
          platforms: linux/amd64
          provenance: false
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Summary
        run: |
          echo "### Image published :whale:" >> $GITHUB_STEP_SUMMARY
          echo '```bash' >> $GITHUB_STEP_SUMMARY
          echo "docker pull ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest" >> $GITHUB_STEP_SUMMARY
          echo '```' >> $GITHUB_STEP_SUMMARY
          echo "Make it public: repo → Packages → aios → Package settings → Change visibility" \
            >> $GITHUB_STEP_SUMMARY