GH actions: split qemu emulated docker builds to native architecture builds

Author: Msprg

.github/workflows/docker.yml

@@ -59,24 +59,64 @@ jobs:
         tags: |
           ${{ env.IMAGE_NAME }}:latest-${{ github.ref_name }}
 
-  release:
+  build-matrix:
     if: github.event_name == 'release'
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      matrix:
+        include:
+          - arch: amd64
+            platform: linux/amd64
+            runner: ubuntu-latest
+          - arch: arm64
+            platform: linux/arm64
+            runner: ubuntu-latest-arm64
     steps:
-    - *checkout-step
-
-    - *setup-qemu-step
-
-    - *login-step
+    - name: Check out repository
+      uses: actions/checkout@v4
 
-    - *setup-buildx-step
+    - name: Login to Docker Hub
+      uses: docker/login-action@v3
+      with:
+        username: ${{ secrets.DOCKERHUB_USERNAME }}
+        password: ${{ secrets.DOCKERHUB_TOKEN }}
+    
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
 
-    - name: Build and push release image
+    - name: Build and push architecture-specific image
       uses: docker/build-push-action@v6
       with:
         context: .
         push: true
-        platforms: linux/amd64,linux/arm64,linux/arm/v7
+        platforms: ${{ matrix.platform }}
+        cache-from: type=gha
+        cache-to: type=gha,mode=max
         tags: |
-          ${{ env.IMAGE_NAME }}:${{ github.event.release.tag_name }}
-          ${{ env.IMAGE_NAME }}:latest
+          ${{ env.IMAGE_NAME }}:${{ github.event.release.tag_name }}-${{ matrix.arch }}
+          ${{ env.IMAGE_NAME }}:latest-${{ matrix.arch }}
+
+  create-manifest:
+    if: github.event_name == 'release'
+    needs: build-matrix
+    runs-on: ubuntu-latest
+    steps:
+    - name: Login to Docker Hub
+      uses: docker/login-action@v3
+      with:
+        username: ${{ secrets.DOCKERHUB_USERNAME }}
+        password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+    - name: Create and push multi-arch manifest for release tag
+      run: |
+        docker manifest create ${{ env.IMAGE_NAME }}:${{ github.event.release.tag_name }} \
+          --amend ${{ env.IMAGE_NAME }}:${{ github.event.release.tag_name }}-amd64 \
+          --amend ${{ env.IMAGE_NAME }}:${{ github.event.release.tag_name }}-arm64
+        docker manifest push ${{ env.IMAGE_NAME }}:${{ github.event.release.tag_name }}
+
+    - name: Create and push multi-arch manifest for latest tag
+      run: |
+        docker manifest create ${{ env.IMAGE_NAME }}:latest \
+          --amend ${{ env.IMAGE_NAME }}:latest-amd64 \
+          --amend ${{ env.IMAGE_NAME }}:latest-arm64
+        docker manifest push ${{ env.IMAGE_NAME }}:latest