docker-image.yml

name: Build & Publish Docker image

on:
  push:
    branches: [ "master" ]
    paths-ignore:
      - "README.md"
      - ".github/workflows/dockerhub-description.yml"
      - ".github/ISSUE_TEMPLATE/**"
  workflow_dispatch:
  
jobs:
  docker:
    runs-on: ubuntu-latest
    permissions:
      contents: write   # erlaubt Git-Tags zu pushen

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # wichtig für git tags

      - name: Calculate version
        id: version
        run: |
          git fetch --tags

          LAST_TAG=$(git tag --list "v*" --sort=-v:refname | head -n 1)

          if [ -z "$LAST_TAG" ]; then
            VERSION="v0.1.0"
          else
            IFS='.' read -r MAJOR MINOR PATCH <<< "${LAST_TAG#v}"
            PATCH=$((PATCH + 1))
            VERSION="v$MAJOR.$MINOR.$PATCH"
          fi

          echo "version=$VERSION" >> $GITHUB_OUTPUT
          echo "Calculated version: $VERSION"

      - name: Create git tag
        run: |
          git tag ${{ steps.version.outputs.version }}
          git push origin ${{ steps.version.outputs.version }}

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

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

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Docker metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ secrets.DOCKERHUB_USERNAME }}/${{ vars.DOCKERHUB_IMAGENAME }}
          tags: |
            type=raw,value=latest
            type=raw,value=${{ steps.version.outputs.version }}

      - name: Build and push (multi-arch)
        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
          platforms: linux/amd64,linux/arm64,linux/arm/v7
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}