javascript - NodeJS websocket server on Plesk doesn't answer -

i new nodejs , have set subdomain work on plesk onyx 17.5.3 server. have done simple websockets chat app doesn't work.

if start app via command line doing:

node server/server.js 

the app works flawlessly. code in server.js is:

"use strict";  process.title = 'node-chat';  const websocketserver = require('ws').server; const port = 9000; const wss = new websocketserver({port: port});  console.log('wss');  let messages = []; wss.on('connection', function (ws) {   console.log('ws connection');   messages.foreach(function(message){     ws.send(message);   });   ws.on('message', function (message) {     messages.push(message);     console.log('message received: %s', message);     wss.clients.foreach(function (conn) {       conn.send(message);     });   }); });  wss.on('error', function(obj){   console.log('ws error');   console.log(obj); });  console.log((new date()) + 'server.js started'); 

if start application using plesks "restart app" doesn't work. doing ps aux can see process working. in log file see has started:

app 17579 stdout: wss app 17579 stdout: fri jul 28 2017 13:52:44 gmt+0200 (cest)server.js started 

but there no log saying websocket server has started or crashed, doesn't work. if try connect client side js app server gives error saying can't connect server:

websocket connection 'ws://server_address:9000/' failed: error in connection establishment: net::err_connection_refused 

any clues?

thanks!

may ask found nodejs logs on plesk? , how able console on plesk?

as answer question:

it port provided not configured allow traffic web node application. that's why i'd recommend using

var port = process.env.port || 9000; 

this line try use port configured in object containing user environment data.