Quick reminder of how to make socket.io listen to an http server. Most examples online that I have found use Express which is ok, but for a small thing might be an overkill

socket.io listen to http

// This is how we can make a socket.io server listen to an http connection
var http = require('http');
var socket = require('socket.io');

// Im not sure if the order is important
http.createServer(function(req,res){
	// handle requests to your http server
});

// we tell socket.io to listen to the http node
socket.listen(http);

// and we tell http to listen to a port
http.listen(80);