Switch to MULTI FROM Dockerfile and use Node 10 for builds (#3199)

Dockerfile

@@ -1,3 +1,12 @@
+FROM node:10 as frontend-builder
+
+WORKDIR /frontend
+COPY package.json package-lock.json /frontend/
+RUN npm install
+
+COPY . /frontend
+RUN npm run build
+
 FROM redash/base:latest
 
 # Controls whether to install extra dependencies needed for all data sources.
@@ -9,10 +18,10 @@ COPY requirements.txt requirements_dev.txt requirements_all_ds.txt ./
 RUN pip install -r requirements.txt -r requirements_dev.txt
 RUN if [ "x$skip_ds_deps" = "x" ] ; then pip install -r requirements_all_ds.txt ; else echo "Skipping pip install -r requirements_all_ds.txt" ; fi
 
-COPY . ./
-RUN npm install && npm run bundle && npm run build && rm -rf node_modules
+COPY . /app
+COPY --from=frontend-builder /frontend/client/dist /app/client/dist
 RUN chown -R redash /app
 USER redash
 
 ENTRYPOINT ["/app/bin/docker-entrypoint"]
-CMD ["server"]
+CMD ["server"]