javascript - Run Websocket on GAE -

i'm trying adapt app using websocket run on gae, reading docs, i'm not find pretty solution problem.

using simple application that: https://github.com/marcosbergamo/gae-nodejs-websocket

this sample demo trying use. i'm receive error when try connect websocket;

follow image request;

in order use websockets, must use google managed vm custom runtime.

https://cloud.google.com/appengine/docs/managed-vms/custom-runtimes

once running, need access server directly ip or cname. cannot go through appspot.com domain.