ci: refactor workflow with matrix strategy, fix latest tag and checkout ref

- Consolidate duplicate backend/frontend jobs into a single matrix job
- Fix latest tag not applied on release (was using is_default_branch)
- Checkout the correct tag ref on release/dispatch events
- Use dynamic image prefix via GITHUB_REPOSITORY for portability
- Scope GHA cache per image to avoid collisions

Author: jaseemjaskp

.github/workflows/docker-publish.yml

@@ -14,61 +14,25 @@ env:
   REGISTRY: ghcr.io
 
 jobs:
-  build-backend:
+  build-and-push:
     runs-on: ubuntu-latest
     permissions:
       contents: read
       packages: write
 
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-
-      - name: Set up QEMU (for multi-platform builds)
-        uses: docker/setup-qemu-action@v3
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-
-      - name: Log in to GHCR
-        uses: docker/login-action@v3
-        with:
-          registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Extract metadata
-        id: meta
-        uses: docker/metadata-action@v5
-        with:
-          images: ${{ env.REGISTRY }}/zipstack/visitran-backend
-          tags: |
-            type=semver,pattern={{version}}
-            type=semver,pattern={{major}}.{{minor}}
-            type=raw,value=latest,enable={{is_default_branch}}
-            type=raw,value=${{ github.event.inputs.tag }},enable=${{ github.event_name == 'workflow_dispatch' }}
-
-      - name: Build and push backend
-        uses: docker/build-push-action@v6
-        with:
-          context: .
-          file: docker/dockerfiles/backend.Dockerfile
-          platforms: linux/amd64,linux/arm64
-          push: true
-          tags: ${{ steps.meta.outputs.tags }}
-          labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
-
-  build-frontend:
-    runs-on: ubuntu-latest
-    permissions:
-      contents: read
-      packages: write
+    strategy:
+      matrix:
+        include:
+          - image: backend
+            dockerfile: docker/dockerfiles/backend.Dockerfile
+          - image: frontend
+            dockerfile: docker/dockerfiles/frontend.Dockerfile
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.release.tag_name || github.event.inputs.tag }}
 
       - name: Set up QEMU (for multi-platform builds)
         uses: docker/setup-qemu-action@v3
@@ -83,25 +47,29 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set image prefix
+        id: repo
+        run: echo "image_prefix=${{ env.REGISTRY }}/${GITHUB_REPOSITORY,,}" >> $GITHUB_OUTPUT
+
       - name: Extract metadata
         id: meta
         uses: docker/metadata-action@v5
         with:
-          images: ${{ env.REGISTRY }}/zipstack/visitran-frontend
+          images: ${{ steps.repo.outputs.image_prefix }}/${{ matrix.image }}
           tags: |
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
-            type=raw,value=latest,enable={{is_default_branch}}
+            type=raw,value=latest,enable=${{ github.event_name == 'release' }}
             type=raw,value=${{ github.event.inputs.tag }},enable=${{ github.event_name == 'workflow_dispatch' }}
 
-      - name: Build and push frontend
+      - name: Build and push ${{ matrix.image }}
         uses: docker/build-push-action@v6
         with:
           context: .
-          file: docker/dockerfiles/frontend.Dockerfile
+          file: ${{ matrix.dockerfile }}
           platforms: linux/amd64,linux/arm64
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-from: type=gha,scope=${{ matrix.image }}
+          cache-to: type=gha,mode=max,scope=${{ matrix.image }}