Fix dockerfile permission error

Allow node to bind to port 80 as non-root

Dockerfile

@@ -1,10 +1,13 @@
 FROM node:16-alpine
 
-
 WORKDIR /opt/app
 
 RUN chown -R 1000:1000 /opt/app
 
+# Allow node to bind to port 80
+RUN apk update && apk add libcap
+RUN setcap CAP_NET_BIND_SERVICE=+eip /usr/local/bin/node
+
 USER 1000:1000
 
 COPY package.json package-lock.json ./
@@ -16,4 +19,4 @@ EXPOSE 80
 
 VOLUME /opt/app/server-data
 
-CMD ["npm", "start"]
+CMD ["/usr/local/bin/node", "server/server.js"]