name: Docker release

# Builds and publishes a multi-arch (linux/amd64 + linux/arm64) Docker
# image whenever a version tag (e.g. "v1.2.3") is pushed, or a release is
# published for one. Written against the GitHub Actions syntax, which
# Gitea Actions runs unmodified — the ${{ github.* }} context and
# secrets.GITHUB_TOKEN are provided as compatibility aliases by Gitea's
# act runner, so this workflow works as-is on either platform.
#
# The image is pushed to this server's own container registry, addressed
# as "<host>/<owner>/<repo>" (e.g. git.example.com/owner/nidus on Gitea,
# or ghcr.io/owner/nidus if this repo is ever mirrored to GitHub).

on:
  push:
    tags:
      - "v*"
  release:
    types: [published]

jobs:
  docker:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: Determine registry, image name, and tags
        id: vars
        run: |
          registry="$(echo "${{ github.server_url }}" | sed -E 's#^https?://##')"
          image_name="$(echo "${{ github.repository }}" | tr '[:upper:]' '[:lower:]')"
          image="${registry}/${image_name}"
          version="${GITHUB_REF_NAME#v}"

          {
            echo "registry=${registry}"
            echo "image=${image}"
            echo "tags=${image}:${version},${image}:latest"
          } >> "$GITHUB_OUTPUT"

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

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

      - name: Log in to the container registry
        uses: docker/login-action@v3
        with:
          registry: ${{ steps.vars.outputs.registry }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: true
          tags: ${{ steps.vars.outputs.tags }}