add github workflow

.github/workflows/docker-build.yml

@@ -0,0 +1,61 @@
+# path: .github/workflows/docker-build.yml
+name: Build and Push Docker Images
+
+on:
+  push:
+    branches:
+      - main
+      - master
+  workflow_dispatch:
+
+env:
+  REGISTRY: docker.io
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU (for multi-arch builds)
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Set image names
+        id: vars
+        run: |
+          echo "backend_image=${{ secrets.DOCKERHUB_USERNAME }}/bierbaron-backend" >> $GITHUB_OUTPUT
+          echo "frontend_image=${{ secrets.DOCKERHUB_USERNAME }}/bierbaron-frontend" >> $GITHUB_OUTPUT
+          echo "sha=${GITHUB_SHA}" >> $GITHUB_OUTPUT
+
+      - name: Build and push backend image
+        uses: docker/build-push-action@v6
+        with:
+          context: ./backend
+          file: ./backend/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: |
+            ${{ steps.vars.outputs.backend_image }}:latest
+            ${{ steps.vars.outputs.backend_image }}:${{ steps.vars.outputs.sha }}
+
+      - name: Build and push frontend image
+        uses: docker/build-push-action@v6
+        with:
+          context: ./frontend
+          file: ./frontend/Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: |
+            ${{ steps.vars.outputs.frontend_image }}:latest
+            ${{ steps.vars.outputs.frontend_image }}:${{ steps.vars.outputs.sha }}