How to use the redis.auth function in redis

var logfmt = require('logfmt');
var passport = require('passport');
var mongoose = require('mongoose');
var redis = require('redis');
var RedisStore = require('connect-redis')(session);
var busboy = require('connect-busboy');


mongoose.connect(process.env.MONGOHQ_URL || 'mongodb://localhost');

if (process.env.REDISTOGO_URL) {
   // inside if statement
  var rtg   = require("url").parse(process.env.REDISTOGO_URL);
  var redis = require("redis").createClient(rtg.port, rtg.hostname);

  redis.auth(rtg.auth.split(":")[1]);
} else {
  var redis = require("redis").createClient();
}

// redis.sadd('guests', 'g1');

var sessionStore = new RedisStore({ client: redis });

var app = express();

app.set('views', __dirname + '/views');
app.engine('html', require('ejs').renderFile);
app.use('/static', express.static(__dirname + '/../static'));

app.use(cookieParser());
app.use(busboy());

function connect() {
  if (client) return;

  if (process.env.REDISTOGO_URL) {
    var rtg = new URL(process.env.REDISTOGO_URL);
    client = redis.createClient(rtg.port, rtg.hostname);
    redis.auth(rtg.password);
  } else {
    client = redis.createClient();
  }

  client.on('error', function(err) {
    console.log('redis error: ', err);
  });
}

var scheduler = function (options) {

    var mongo = require('mongodb')
        , redis = require('redis')
        , async = require('async')
        , userBee = require('./user-bee')(options);

    var mongoServer = new mongo.Server(options.mongodb.host, options.mongodb.port, options.mongodb.options);
    var db = new mongo.Db('user_bee', mongoServer, {safe:false});
    var laterRefs = new Array();

    var redis = redis.createClient(options.redis.port, options.redis.host);
    if (options.redis.hasOwnProperty('password')) {
        redis.auth(options.redis.password);
    }

    /**
     * Private functions
     */

    var _processTrigger = function (trigger) {
        db.collection('attributes', function (err, collection) {
            if (err) {
                console.error("Could not fetch attributes collection from mongodb: " + err);
                return false;
            }

            //TODO: Exclude unsubscribed users
            //Fetch users for whom this trigger has not been triggered yet
            var queryCondition = ('query' in trigger) ? trigger.query : ('queryFunction' in trigger ? eval('(' + trigger.queryFunction + ')()') : {})