Simple subdomain with Express - node.js

Question

I am trying to use Express as my server in MEAN stack on AWS. However I've ran into a issue trying to setup subdomains. I have my main domain name domain.com and id like to have app.domain.com.. However I've tried everything I've found online to write the functionality into the server.js file and nothing works. How can I easily accomplish this to make the second function instead of loading on Port 8000 load up at my app.domain.com sub domain? Thanks in advance!
var express = require('express');
// Main Website
var web = express();
web.get('/', function (req, res){
res.sendFile('/web/index.html', { root: '.' })
});
var port = 9000;
web.listen(port);
console.log('Web Listening on port', port);
//Main Application
var app = express();
app.get('/', function (req, res){
res.sendFile('/app/index.html', { root: '.' })
});
var port = 8000;
app.listen(port);
console.log('Web Listening on port', port);
Update:
I tried using Vhost here but it loads the same thing for both the main domain and the sub domain and so it does not work. here is the code I used:
var express = require('express');
var connect = require('connect');
var http = require('http');
var vhost = require('vhost');
// Main Website
var web = express();
web.get('/', function (req, res){
res.sendFile('/web/index.html', { root: '.' })
});
var port = 9000;
web.listen(port);
console.log('Web Listening on port', port);
//Main Application
var app = connect()
app.use(vhost('app.domain.com', function (req, res) {
res.sendFile('/app/index.html', { root: '.' })
httpServer.emit('request', req, res)
}))
app.listen(8000)
I don't really need these to be on separate ports that was just something I was trying originally. But either way does not work still..

Answer 1

There's no need for any thing outside of node.js serving on one port. It's just a matter of routing based on the http header.
var express = require('express');
var http = require('http');
var vhost = require('vhost');
// Main Website
var webapp = express();
webapp.get('/', function (req, res){
res.sendFile('/web/index.html', { root: '.' });
});
//Main Application
var mainapp = express();
mainapp.use(function (req, res) {
res.sendFile('/app/index.html', { root: '.' });
}));
//Virtual Routing Application
var app = express();
app.use(vhost('app.domain.com', webapp));
app.use(vhost('domain.com', mainapp));
app.use(vhost('www.domain.com', mainapp));
app.listen(9000);

Answer 2

Since you're using AWS, you can use Application Load Balancer to achieve your goals.
Setup an ALB, and point both domains to the ALB CNAME.
Then you will need to create 2 target groups, one for app.domain.com and another one for domain.com.
Target Group: App
protocol: HTTP
port: 8000
Target Group: Web
protocol: HTTP
port: 9000
Attach your EC2 instance to both target groups
Target group > Targets > Edit > Add to registered
Finally you will have to add an HTTP listener to your ALB, and setup the rules to forward each domain to its target group.
After the rules are set, when you enter to app.domain.com the ALB will forward the request to your express app listening on port 8000, and when browsing domain.com the one listening on port 9000 will be used.

Answer 3

If you are using Route53 I recommend you to use Records Set to redirect both domain and subdomain to the same ec2 instance via the ip address then you can use ngix like the comments say in this post enter link description here
Using the load balancer (ALB) generates montly the minimum cost of 21.96USD but using Route53 it is minimum of 1USD or less.
If you dont want to use a proxy like nginx you can have s3 website hosting with a low cost, arround 6USD and the route 53 routing by 1USD minimum per month and if you have REST API services you can call from front end to your instance depending the site accessed with no problems.
Regards,