javascript - Using Socket.IO from Node.js to connect to external server -

background: have node.js server running on localhost (call server a); , external server running node.js @ https://example.net:3000 (call server b). not control or have access server b (it dashboard site iot device in home), need connect using socket.io , emit specific message.

i can connect flat javascript file (client-side), need running server side (ultimate goal make can call http request); , examples such how connect 2 node.js servers websockets? suggest should able use socket.io-client node.js same code achieve same results. when run code node.js, cannot connect socket.

below code works in flat javascript file. know works because see 'socket connect' in console, , can test the socket emit @ end.

var myemail = "email@gmail.com"; var device_id = '12345'; // create socketio instance, connect var socket = io.connect('https://example.net:3000');  socket.on('connect', function(){     try {         console.log('socket connect');         socket.emit('configure', {email:myemail, deviceid:device_id});     } catch(e) {         console.log(e);     } }); socket.emit("/" + device_id, "45678"); 

...and below code cannot work when running node.js instance. i'd expect message 'socket connect' in command line log , nothing.

var express=require('express'); var http=require('http'); var app=express(); var server = http.createserver(app); //variables  var myemail = "email@gmail.com"; var device_id = '12345';   var io = require('socket.io-client'); var socket = io.connect('https://example.net:3000');  //connect listener socket.on('connect', function(){    try {       console.log('socket connect');       socket.emit('configure', {email:myemail, deviceid:device_id});    } catch(e) {      console.log(e);    } }); socket.emit("/" + device_id, "45678"); 

any ideas?

update

ran debug utility, results included linked image below. key thing see engine.io tries xhr poll, , gets 503 response server. (obviously not true 'temporary error' server again, works running client-side js in chrome).

debugging output image link

i think line causing issue :

var socket = io.connect('https://example.net:3000'); 

i managed make working example using code :

const myemail = "email@gmail.com"; const device_id = '12345';  var socket = require('socket.io-client')('https://example.net:3000'); socket.on('connect', function(){  try{    console.log('socket connect');    socket.emit('configure', {email:myemail, deviceid:device_id});  }catch(e){ console.log(e); } });