Upload together to avoid overwriting.

Author: Mailaender

.github/workflows/docker.yml

@@ -3,10 +3,10 @@ name: Publish Docker Image
 on:
   push:
     tags:
-    - '*'
+      - '*'
 
 jobs:
-  build-and-push-image:
+  build:
     strategy:
       matrix:
         include:
@@ -49,11 +49,67 @@ jobs:
             openhv/server
             ghcr.io/${{ github.repository }}
 
-      - name: Build and push Docker image
+      - name: Build and push platform image
         uses: docker/build-push-action@v6
         with:
           context: .
           platforms: ${{ matrix.platform }}
           push: true
-          tags: ${{ steps.meta.outputs.tags }}
+          tags: ${{ steps.meta.outputs.tags }}-${{ matrix.arch }}
           labels: ${{ steps.meta.outputs.labels }}
+
+      - name: Upload image digest
+        run: |
+          mkdir -p digests
+          docker buildx imagetools inspect ${{ steps.meta.outputs.tags }}-${{ matrix.arch }} --format '{{json .}}' > digests/${{ matrix.arch }}.json
+        if: always()
+      - name: Upload digest artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: digest-${{ matrix.arch }}
+          path: digests/${{ matrix.arch }}.json
+
+  manifest:
+    needs: build
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Download digest artifacts
+        uses: actions/download-artifact@v4
+        with:
+          path: digests
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract tags and labels for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            openhv/server
+            ghcr.io/${{ github.repository }}
+
+      - name: Create and push multi-arch manifest
+        run: |
+          for tag in $(echo "${{ steps.meta.outputs.tags }}" | tr ',' '\n'); do
+            docker buildx imagetools create \
+              -t "$tag" \
+              "$tag-amd64" \
+              "$tag-arm64"
+          done