Fix cross-arch image (#48)

.github/workflows/build-image.yaml

@@ -39,16 +39,6 @@ jobs:
           # list of Docker images to use as base name for tags
           images: |
             ghcr.io/${{github.repository}}
-          # generate Docker tags based on the following events/attributes
-          tags: |
-            type=edge,branch=main,prefix=releases-
-            type=schedule
-            type=ref,event=branch
-            type=ref,event=pr
-            type=semver,pattern={{version}}
-            type=semver,pattern={{major}}.{{minor}}
-            type=semver,pattern={{major}}
-            type=sha
 
       # https://github.com/docker/setup-qemu-action
       - name: Set up QEMU (arm64)
@@ -75,12 +65,75 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Build and push
-        uses: docker/build-push-action@v3
+        id: build-and-push
+        uses: docker/build-push-action@v4
         with:
           context: .
           platforms: ${{ matrix.docker_build_arch }}
-          push: ${{ github.event_name != 'pull_request' }}
-          tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=image,name=ghcr.io/${{github.repository}},push-by-digest=true,name-canonical=true,push=${{ github.event_name != 'pull_request' }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
+
+      - name: Export digest
+        if: github.event_name != 'pull_request'
+        run: |
+          mkdir -p /tmp/digests
+          digest="${{ steps.build-and-push.outputs.digest }}"
+          touch "/tmp/digests/${digest#sha256:}"
+      - name: Upload digest
+        if: github.event_name != 'pull_request'
+        uses: actions/upload-artifact@v3
+        with:
+          name: digests
+          path: /tmp/digests/*
+          if-no-files-found: error
+          retention-days: 1
+
+  merge:
+    runs-on: ubuntu-latest
+    needs:
+      - build
+    steps:
+      - name: Download digests
+        if: github.event_name != 'pull_request'
+        uses: actions/download-artifact@v3
+        with:
+          name: digests
+          path: /tmp/digests
+      - name: Set up Docker Buildx
+        if: github.event_name != 'pull_request'
+        uses: docker/setup-buildx-action@v2
+      - name: Docker meta
+        id: meta
+        if: github.event_name != 'pull_request'
+        uses: docker/metadata-action@v4
+        with:
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            type=edge,branch=main,prefix=releases-
+            type=schedule
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha
+          images: ghcr.io/${{github.repository}}
+      - name: Login to Docker Hub
+        uses: docker/login-action@v2
+        if: github.event_name != 'pull_request'
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Create manifest list and push
+        working-directory: /tmp/digests
+        if: github.event_name != 'pull_request'
+        run: |
+          docker buildx imagetools create $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
+            $(printf 'ghcr.io/${{github.repository}}@sha256:%s ' *)
+      - name: Inspect image
+        if: github.event_name != 'pull_request'
+        run: |
+          docker buildx imagetools inspect ghcr.io/${{github.repository}}:${{ steps.meta.outputs.version }}