Add docker build push to ghcr workflow

Author: hweej

.github/workflows/docker-publish.yml

@@ -0,0 +1,60 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - main
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GitHub Container Registry
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          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=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

README.md

@@ -44,9 +44,38 @@ The app will be available at `http://localhost:8080`
    ]
    ```
 
+3. The `public/config.json` file is gitignored to keep credentials safe.
+
 ## Docker Deployment
 
-When deploying with Docker, mount your `config.json` as a volume:
+### Using Pre-built Image from GHCR
+
+Pull and run the latest image from GitHub Container Registry:
+
+```bash
+docker run -d -p 8080:80 \
+  -v $(pwd)/public/config.json:/usr/share/nginx/html/config.json:ro \
+  ghcr.io/mskcc/cellxgene-dash:main
+```
+
+Or update `docker-compose.yml` to use the pre-built image:
+
+```yaml
+version: '3.8'
+
+services:
+  cellxgene-dash:
+    image: ghcr.io/mskcc/cellxgene-dash:main
+    ports:
+      - "8080:80"
+    volumes:
+      - ./public/config.json:/usr/share/nginx/html/config.json:ro
+    restart: unless-stopped
+```
+
+### Building Locally
+
+When building locally, mount your `config.json` as a volume:
 
 ```bash
 docker run -d -p 8080:80 \