add different platforms for docker img (#417)

I saw this [issue](#413) and
thought that it would be great for contributing to this project.

- Made some modifications to `docker.sh ` and to `release.yaml`
- Breaking changes: no

.github/workflows/release.yaml

@@ -23,4 +23,4 @@ jobs:
         with:
           fetch-depth: 0
       - run: echo ${{ secrets.DOCKER_ACCESS_TOKEN }} | docker login -u ${{ secrets.DOCKER_USERNAME }} --password-stdin
-      - run: tools/docker.sh
+      - run: tools/docker.sh "linux/amd64,linux/arm64"

tools/docker.sh

@@ -2,7 +2,30 @@
 
 set -e
 
-for tag in latest $(git tag --points-at | sed s/^v//); do
-  docker build -t raviqqe/muffet:$tag .
-  docker push raviqqe/muffet:$tag
-done
+check_buildx(){
+    docker buildx version &>/dev/null
+    return $?
+}
+
+build_image() {
+    local platforms=${1:-} 
+    if [ ! -z "$platforms" ] && check_buildx; then
+        echo "Building for platforms: $platforms"
+        # Build for each git tag and latest
+        for tag in latest $(git tag --points-at | sed s/^v//); do
+          docker buildx build \
+             --platform "$platforms" \
+             --tag raviqqe/muffet:$tag \
+             --push \
+             .
+        done
+    else
+        for tag in latest $(git tag --points-at | sed s/^v//); do
+          docker build -t raviqqe/muffet:$tag .
+          docker push raviqqe/muffet:$tag
+        done
+    fi
+}
+
+
+build_image "$@"