Add docker build to CI script

.github/workflows/test.yml

@@ -16,5 +16,38 @@ jobs:
     - run: nix develop --impure -c ./test-setup.sh /tmp
     - run: nix develop --impure -c pytest
 
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: set lower case owner name
+      run: |
+        echo "OWNER_LC=${OWNER,,}" >>${GITHUB_ENV}
+      env:
+        OWNER: '${{ github.repository_owner }}'
+    - name: set tag to latest
+      run: |
+        sed -i 's/  contents/  tag = "latest";\n  contents/' nix/docker.nix nix/docker_static.nix
+    - name: Build docker image
+      run: nix develop --impure -c build_docker
+    - name: Load app image
+      run: docker load -i docker-image-ekklesia-portal.tar
+      if: github.ref == 'refs/heads/piraten-bund'
+    - name: Load static image
+      run: docker load -i docker-image-ekklesia-portal-static.tar
+      if: github.ref == 'refs/heads/piraten-bund'
+    - name: Login to docker registry
+      run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
+      if: github.ref == 'refs/heads/piraten-bund'
+    - name: Push docker image
+      run: docker push ghcr.io/${{ env.OWNER_LC }}/ekklesia-portal:latest
+      if: github.ref == 'refs/heads/piraten-bund'
+    - name: Push docker static image
+      run: docker push ghcr.io/${{ env.OWNER_LC }}/ekklesia-portal-static:latest
+      if: github.ref == 'refs/heads/piraten-bund'
+    - uses: actions/upload-artifact@v3
+      with:
+        name: Ekklesia Docker Images
+        path: docker-image-*.tar
 
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