container-build.yml

name: Build and publish container image

on:
  # run when tagging or pushing to master
  push:
    branches: [master]
    tags: ["*"]

permissions:
  packages: write # ghcr access
  contents: write # create releases

env:
  # GitHub Container Registry hostname
  GHCR_HOSTNAME: ghcr.io

jobs:
  build_and_push:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout the latest SHA for this branch
        uses: actions/checkout@v4
        if: github.event_name != 'workflow_dispatch'

      - name: Checkout the specified tag
        uses: actions/checkout@v4
        if: github.event_name == 'workflow_dispatch'
        with:
          ref: ${{ github.event.inputs.tag }}

      - name: Get the latest Dockerfile if needed
        if: github.event_name == 'workflow_dispatch'
        run: |
          if [[ ! -f Dockerfile ]]; then
            git fetch --depth=1 origin master
            git checkout origin/master -- Dockerfile
          fi

      - name: Setup Docker Buildx
        id: buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Prepare
        id: prep
        run: |
          VERSION="${{ github.event.inputs.tag }}"
          if [[ $GITHUB_REF == refs/tags/* ]]; then
            VERSION="${GITHUB_REF/refs\/tags\//}"
          fi
          if [[ -z "$VERSION" ]]; then
            VERSION="ref-${GITHUB_SHA::8}"
          fi
          echo "VERSION=${VERSION}" >> $GITHUB_OUTPUT

      - name: Generate images meta
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: |
            ${{ env.GHCR_HOSTNAME }}/${{ github.repository }}
          tags: |
            type=raw,value=${{ steps.prep.outputs.VERSION }}

      - name: Build the container image
        uses: docker/build-push-action@v5
        with:
          push: true
          builder: ${{ steps.buildx.outputs.name }}
          platforms: linux/amd64,linux/arm64
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max