Use matrix build for docker platforms

.github/workflows/docker.yml

@@ -2,13 +2,27 @@
 name: docker
 on: pull_request
 
+
+env:
+  REGISTRY_IMAGE: ghcr.io/${{ github.repository_owner }}/grafanimate
+
 jobs:
-  docker:
-    name: build docker
+  build:
     runs-on: ubuntu-22.04
+    strategy:
+      fail-fast: false
+      matrix:
+        platforms:
+          - linux/amd64
+          - linux/arm64
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
@@ -19,11 +33,61 @@ jobs:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
-      - name: Build and push
+      - name: Build and push by digest
+        id: build
         uses: docker/build-push-action@v5
         with:
           context: .
-          platforms: linux/amd64,linux/arm64
-          push: true
-          tags: |
-            ghcr.io/${{ github.repository_owner }}/grafanimate:latest
+          platforms: ${{ matrix.platform }}
+          labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=image,name=${{ env.REGISTRY_IMAGE }},push-by-digest=true,name-canonical=true,push=true
+
+          #push: true
+          #cache-from: type=registry,ref=ghcr.io/${{ github.repository_owner }}/grafanimate:latest
+          #cache-to: type=inline
+          #tags: |
+          #  ghcr.io/${{ github.repository_owner }}/grafanimate:latest
+      - name: Export digest
+        run: |
+          mkdir -p /tmp/digests
+          digest="${{ steps.build.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"
+      - name: Upload digest
+        uses: actions/upload-artifact@v3
+        with:
+          name: digests
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+
+  merge:
+    runs-on: ubuntu-22.04
+    needs:
+      - build
+    steps:
+      - name: Download digests
+        uses: actions/download-artifact@v3
+        with:
+          name: digests
+          path: /tmp/digests
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_IMAGE }}
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Create manifest list and push
+        working-directory: /tmp/digests
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf '${{ env.REGISTRY_IMAGE }}@sha256:%s ' *)
+      - name: Inspect image
+        run: |
+          docker buildx imagetools inspect ${{ env.REGISTRY_IMAGE }}:${{ steps.meta.outputs.version }}