emulator.js

var poolModule 		= require('generic-pool');
var exec 		      = require('child_process').exec;
var randomstring 	= require("randomstring");


var ualist = ["Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10; rv:33.0) Gecko/20100101 Firefox/33.0", "Mozilla/5.0 (Windows NT 6.3; rv:36.0) Gecko/20100101 Firefox/36.0", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1944.0 Safari/537.36", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.517 Safari/537.36"];
var urllist = ["http://host.com", "http://host.com/hello", "http://stand.me/2015/"];

var pool = poolModule.Pool({
    name     : 'emulator',
    create   : function(callback) {
		var ua = ualist[Math.floor(Math.random()*ualist.length)];
		var url = urllist[Math.floor(Math.random()*urllist.length)];
		var filename = randomstring.generate();
		var cmd = "phantomjs ./render.js " + url + " ./tmp/" + filename + ".jpg " + "\"" + ua + "\"";
		var task = exec(cmd);
		console.log(cmd);
        callback(null, ua);
    },
    destroy  : function(client) { /*client.end();*/ },
    max      : 25,
    min      : 10, 
    idleTimeoutMillis : 15000,
    log : false 
});