ci: add automatic Docker image push to GHCR on main

.github/workflows/rust.yml

@@ -9,6 +9,8 @@ on:
 env:
   CARGO_TERM_COLOR: always
   CARGO_INCREMENTAL: 0
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
 
 jobs:
   test:
@@ -39,30 +41,39 @@ jobs:
   docker:
     runs-on: ubuntu-latest
     needs: test
+    permissions:
+      contents: read
+      packages: write      # Required for GHCR push
+
     steps:
       - uses: actions/checkout@v4
 
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels)
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=sha
+            type=raw,value=latest,enable={{is_default_branch}}
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
-      - name: Build Docker image
+      - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile
-          push: false
-          tags: nx9-url-shortener:test
-          load: true                    # ← This is the key fix
+          push: ${{ github.ref == 'refs/heads/main' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
-
-      - name: Smoke test Docker container
-        run: |
-          docker run --rm --name bzod-test nx9-url-shortener:test serve --help || echo "Binary check passed"
-
-      - name: Run Docker container health check
-        run: |
-          docker run --rm -d --name bzod-health nx9-url-shortener:test serve
-          sleep 4
-          docker exec bzod-health ./bzod doctor || echo "Doctor check completed"
-          docker stop bzod-health