[NodeJS] Check port availability for list of IPs

check_port_for_hosts.js

var net = require('net');
var Promise = require('bluebird');

function checkConnection(host, port, timeout) {
    return new Promise(function(resolve, reject) {
        timeout = timeout || 10000;     // default of 10 seconds
        var timer = setTimeout(function() {
            reject("timeout");
            socket.end();
        }, timeout);
        var socket = net.createConnection(port, host, function() {
            clearTimeout(timer);
            resolve();
            socket.end();
        });
        socket.on('error', function(err) {
            clearTimeout(timer);
            reject(err);
        });
    });
}

var checkIP = function(ip,port){
checkConnection(ip, port)
        .then(function(){
            return console.log("working: "+ip);
    }, function(err) {
        return console.log("not-working: "+ip);
    });
}

//Array of ips to check
var ips = "[List Of IPS]"

//Port number to be checked
var port = "<port-number>"

//check each ip
for(i in ips){
    checkIP(ips[i]);
}