Simple PhantomJS script to warm multiple pages as fast as possible

warm-item-pages.js

/*
 * Warm a WDL web server by requesting our top pages using a full web browser
 */

var system = require('system');

var page = new WebPage(),
    hostnames = [],
    items = [],
    customHeaders = {};

system.args.slice(1).forEach(function (arg, i) {
    arg = arg.trim();

    if (arg.indexOf("--header=") === 0) {
        var header_arg = arg.slice(9),
            parts = header_arg.split(":").map(function (i) { return i.trim(); });
        customHeaders[parts[0]] = parts[1];
    } else if (!arg.match(/^[0-9]+$/)) {
        hostnames.push(arg);
    } else {
        items.push(arg);
    }
});

if (hostnames.length < 1 || items.length < 1) {
    console.log('Usage:', system.args[0], '[--header=key:value] hostname [hostname2…] id_1 [id_2 …]');
    phantom.exit();
}

if (customHeaders) {
    console.log("Setting custom headers:", JSON.stringify(customHeaders, null, 4));
    page.customHeaders = customHeaders;
}

console.log("Loading item pages from", hostnames.join(" "), "for items:", items.join(" "));

var urls = [],
    languages = ['ar', 'en', 'es', 'fr', 'pt', 'ru', 'zh'],
    pages = ['/', '/zoom/'];

items.forEach(function (item) {
    languages.forEach(function (lang) {
        hostnames.forEach(function (hostname) {
            pages.forEach(function (page) {
               urls.push("http://" + hostname + '/' + lang + "/item/" + item + page);
            });
        });
    });
});

function nextPage() {
    if (urls.length < 1) {
        phantom.exit();
    }

    var loadStart = new Date(),
        url = urls.shift();

    page.open(url, function (status) {
        if (status !== 'success') {
            console.log('Unable to load ' + url + ': ' + status);
        } else {
            console.log('Loaded', url, 'in', ((new Date() - loadStart) / 1000).toFixed(1), 'seconds');
        }
        nextPage();
    });
}

nextPage();