Set up QEMU and Docker Buildx for multi-platform builds

Author: dvershinin

.github/workflows/dockerpublish.yml

@@ -40,6 +40,14 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: all
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
       - name: Extract metadata (tags, labels) for Docker
         id: meta
         uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38