Publish container to GHCR

.github/workflows/build.yml

@@ -9,6 +9,8 @@ on:
 permissions:
   # Checkout repository
   contents: read
+  # Push container images
+  packages: write
 
 jobs:
   build:
@@ -30,7 +32,7 @@ jobs:
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v2
 
-    - name: Build image
+    - name: Build image for tests
       id: build
       uses: docker/build-push-action@v5
       with:
@@ -71,3 +73,34 @@ jobs:
         --workdir /usr/local/src
         ${{ steps.build.outputs.imageid }}
         /bin/sh -c 'apt-get install -y mypy python3-pytest && mypy --show-error-codes .'
+
+    - name: Docker meta
+      id: meta
+      if: ${{ github.event_name != 'pull_request' || always() }}
+      uses: docker/metadata-action@v5
+      with:
+        images: |
+          ghcr.io/${{ github.repository }}
+        tags: |
+          type=edge
+          type=ref,event=pr
+          type=semver,pattern={{version}}
+          type=semver,pattern={{major}}.{{minor}}
+          type=semver,pattern={{major}}
+
+    - name: Login to GitHub Container Registry
+      if: ${{ github.event_name != 'pull_request' || always() }}
+      uses: docker/login-action@v3
+      with:
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Build and push image
+      if: ${{ github.event_name != 'pull_request' || always() }}
+      uses: docker/build-push-action@v5
+      with:
+        file: Containerfile
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}