index.js

var cheerio = require('cheerio');
var request = require('request');
var validator = require('validator');
var stats = {
    protocols: [
        'http',
        'https',
        'ftp'
    ],
    require_protocol: true
};

var attributeMapping = {
    'og': 'facebook'
};

function extractDomain(url) {
    var domain;
    //find & remove protocol (http, ftp, etc.) and get domain
    if (url.indexOf("://") > -1) {
        domain = url.split('/')[2];
    }
    else {
        domain = url.split('/')[0];
    }

    //find & remove port number
    domain = domain.split(':')[0];

    return domain;
}

module.exports = function(link, cb) {
    if (!link) {
        cb({ message: 'Url is empty' }, null);
        return;
    }

    if (!validator.isURL(link, stats)) {
        cb({ message: 'Url is not valid' }, null);
        return;
    }

    request(link, function(error, response, body) {

        if (error || response === undefined) {
            cb({ message: 'Empty response' });
            return;
        }

        var $ = cheerio.load(body);
        var meta = $('meta');
        var title = $('title').text();
        var images = $('img');
        var metatags = {};
        var images2 = [];

        /* Purge invalid tags on the object */
        meta = meta.filter(function(m) {
            return meta[m].hasOwnProperty('attribs')
                && meta[m].attribs !== undefined
                // Has either property or name:
                && (meta[m].attribs.property !== undefined ||
                    meta[m].attribs.name !== undefined)
                && meta[m].attribs.content !== undefined;
        });

        images.each(function(m) {
            var src = "";

            if(validator.isURL(images[m].attribs.src, stats)){
                src = images[m].attribs.src;
            }else{
                src = extractDomain(link) +'/'+ images[m].attribs.src;
            }

            images2.push({
                src: src
            });
        });

        meta.each(function(m) {
            var _meta = meta[m];

            var property;

            if (_meta.attribs.property) {
                property = _meta.attribs.property.split(':');
            } else {
                property = _meta.attribs.name.split(':');
            }

            /*
             * Checking if property name is mapped to a value, if it's not,
             * use it as it is
             */
            var propertyName = attributeMapping[property[0]] ? attributeMapping[property[0]] : property[0];
            var propertyValue = property[1];

            /*
             * Checks if the meta tag 'vendor' is present on our metatags hash
             */

            if (!metatags.hasOwnProperty(propertyName)) {
                metatags[propertyName] = {};
            }

            if(typeof propertyValue == 'undefined'){
               metatags[propertyName] = _meta.attribs.content;
            }else{
                metatags[propertyName][propertyValue] = _meta.attribs.content;
            }
        });

        /*
         *   Include tag title
        */
        metatags['title'] = title;
        /*
         *   Include images from document
        */

        metatags['otherimages'] = images2;

        cb(null, metatags);
    });
};