Add GitHub Actions workflow for Docker build and push to DockerHub

.github/workflows/docker-build-push.yml

@@ -0,0 +1,47 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    types: [ closed ]
+    branches: [ main ]
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    # Only run on merged PRs or direct pushes to main
+    if: github.event_name == 'push' || (github.event_name == 'pull_request' && github.event.pull_request.merged == true)
+    
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      
+      - name: Login to DockerHub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      
+      - name: Extract metadata for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ secrets.DOCKERHUB_USERNAME }}/duckai
+          tags: |
+            type=sha,format=short
+            type=ref,event=branch
+            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/main' }}
+      
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=registry,ref=${{ secrets.DOCKERHUB_USERNAME }}/duckai:buildcache
+          cache-to: type=registry,ref=${{ secrets.DOCKERHUB_USERNAME }}/duckai:buildcache,mode=max