Adds docker build only for the PRS and push

.github/workflows/docker_build.yml

@@ -0,0 +1,81 @@
+name: Build Docker Images for backend
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - "backend/**"
+      - ".github/workflows/docker_build.yml"
+  pull_request:
+    branches:
+      - master
+    paths:
+      - "backend/**"
+      - ".github/workflows/docker_build.yml"
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-api-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for API Docker
+        id: meta_api
+        uses: docker/metadata-action@v3
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}_api
+
+      - name: Build and push API Docker image
+        uses: docker/build-push-action@v3
+        with:
+          context: backend/
+          file: backend/Dockerfile_CPU
+          push: false
+          tags: ${{ steps.meta_api.outputs.tags }}
+          labels: ${{ steps.meta_api.outputs.labels }}
+
+  build-and-push-worker-image:
+    needs: build-and-push-api-image
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Worker Docker
+        id: meta_worker
+        uses: docker/metadata-action@v3
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}_worker
+
+      - name: Build and push Worker Docker image
+        uses: docker/build-push-action@v3
+        with:
+          context: backend/
+          file: backend/Dockerfile
+          push: false
+          tags: ${{ steps.meta_worker.outputs.tags }}
+          labels: ${{ steps.meta_worker.outputs.labels }}