app.js

const cluster = require('cluster'),
	http = require('http'),
	numCPUs = require('os').cpus().length,
	express = require('express'),
	app = express(),
	bodyParser = require('body-parser'),
	morgan = require('morgan'),
	cookieParser = require('cookie-parser'),
	helmet = require('helmet'),
	passport = require('passport'),
	session = require('express-session'),
	RedisStore = require('connect-redis')(session);

	// Get App Configurations
	conf = require('./config'),

	// Get port from environment and store in Express.
	port = normalizePort(process.env.PORT || '4000');
	app.set('port', port);

//Passport Strategy Declaration
require('./utility/passportStrategy')(passport);
// Morgan Logger
app.use(morgan('short'));
// Include Security Best Practices
app.use(helmet());
// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ limit: '50mb', extended: false }));

// parse application/json
app.use(bodyParser.json({ limit: '50mb' }));

// parse cookies
app.use(cookieParser());

app.use(express.static('./public'));
app.set('views', './views');
app.set('view engine', 'pug');

// required for passport
app.use(session({
    store: new RedisStore({
        host: 'redis-15299.c16.us-east-1-3.ec2.cloud.redislabs.com',       //where redis store is
        port: 15299,              //default redis port
		prefix: 'carter',         //prefix for sessions name is store
		pass: 'AE29pznLyYsfgZtx7vL9C1PLV7b5CQO5'
	}),
	secret: 'carterhadasecret',
	saveUninitialized : true,
	resave :true})); // session secret
app.use(passport.initialize());
app.use(passport.session()); // persistent login sessions

// routes
const base = require('./routes/index')();
const user = require('./routes/user')(passport);
const products = require('./routes/api/products')();
const orders = require('./routes/api/orders')();
const cart = require('./routes/api/cart')();
app.use('/', base);
app.use('/auth', user);
app.use('/products', products);
app.use('/orders', orders);
app.use('/cart', cart);

let server,
	mongoose = require('mongoose');

mongoose.Promise = require('bluebird');

// Setting up Node Cluster
if (cluster.isMaster) {
	console.log(`Master ${process.pid} is running`);
	// Fork workers.
	for (let i = 0; i < numCPUs; i += 1) {
		cluster.fork();
	}
	cluster.on('exit', (worker) => {
		console.log(`worker ${worker.process.pid} died`);
	});
} else {
	// Workers can share any TCP connection
	// In this case it is an HTTP server
	// Start a MongoDB connection with Mongoose
	mongoose.connect(conf.dbUrl, {
		useNewUrlParser: true,
			/* other options */
		}).then(() => { /** ready to use. The `mongoose.connect()` promise resolves to undefined. */
			console.log('Connected to MongoDB');
		},(err) => { /** handle initial connection error */ 
			console.log(`Unable to connect to MongoDB : ${err}`);
		}
	);
	server = http.Server(app);
	server.listen(port, '0.0.0.0');
	server.on('error', onError);
	server.on('listening', onListening);

	console.log(`Worker ${process.pid} started`);
}

function normalizePort(val) {
	const intPort = parseInt(val, 10);

	if (isNaN(intPort)) {
		// named pipe
		return val;
	}

	if (intPort >= 0) {
		// port number
		return intPort;
	}

	return false;
}	

/**
 * Event listener for HTTP server "error" event.
 */

function onError(error) {
	if (error.syscall !== 'listen') {
		throw error;
	}

	const bind = typeof port === 'string' ? `Pipe ${port}` : `Port ${port}`;

	// handle specific listen errors with friendly messages
	switch (error.code) {
		case 'EACCES':
			console.error(`${bind} requires elevated privileges`);
			process.exit(1);
			break;
		case 'EADDRINUSE':
			console.error(`${bind} is already in use`);
			process.exit(1);
			break;
		default:
			throw error;
	}
}

/**
 * Event listener for HTTP server "listening" event.
 */

function onListening() {
	const addr = server.address();
	const bind = typeof addr === 'string' ? `pipe ${addr}` : `port ${addr.port}`;
	console.log(`Listening on ${bind}`);
}