db-config.js

var databaseURL = "wePlay";
var collections = ["users", "game"];

if(process.env.VCAP_SERVICES){

    var env = JSON.parse(process.env.VCAP_SERVICES);
   var mongo = env['mongodb-1.8'][0]['credentials'];
}
else{  
    var mongo = {
        "hostname":"localhost",
        "port":27017,
        "username":"",
        "password":"",
        "name":"",
        "db":"db"
    };
}
var generate_mongo_url = function(obj){  
    obj.hostname = (obj.hostname || 'localhost');
    obj.port = (obj.port || 27017);
    obj.db = (obj.db || 'test');
    if(obj.username && obj.password){
        return "mongodb://" + obj.username + ":" + obj.password + "@" + obj.hostname + ":" + obj.port + "/" + obj.db;
    }
    else{
        return "mongodb://" + obj.hostname + ":" + obj.port + "/" + obj.db;
    }
};
var mongourl = generate_mongo_url(mongo);

var db = require('mongojs').connect(mongourl, collections);
module.exports = db;