use submodule

excalidraw/Dockerfile

@@ -1,14 +1,20 @@
-FROM node:18 AS build
+FROM --platform=${BUILDPLATFORM} node:18 AS build
 
-WORKDIR /home/node/app
+WORKDIR /opt/node_app
 
 COPY . .
 
-RUN npm install
-RUN cd excalidraw-app && npm run build:app:docker
+# do not ignore optional dependencies:
+# Error: Cannot find module @rollup/rollup-linux-x64-gnu
+RUN --mount=type=cache,target=/root/.cache/yarn \
+    npm_config_target_arch=${TARGETARCH} yarn --network-timeout 600000
 
-FROM nginx:1.21-alpine
+ARG NODE_ENV=production
 
-COPY --from=build /home/node/app/excalidraw-app/build /usr/share/nginx/html
+RUN npm_config_target_arch=${TARGETARCH} yarn build:app:docker
+
+FROM --platform=${TARGETPLATFORM} nginx:1.27-alpine
+
+COPY --from=build /opt/node_app/excalidraw-app/build /usr/share/nginx/html
 
 HEALTHCHECK CMD wget -q -O /dev/null http://localhost || exit 1