Port numbers not hiding in nginx reverse proxy (next js server)

Question

I am trying to deploy a next-js app by create-next-app, I have a custom express server like this -

const express = require('express')
const next = require('next')
const dev = process.env.NODE_ENV !== 'production'
const nextApp = next({ dev })
const handle = nextApp.getRequestHandler()

const fs = require('fs')

nextApp.prepare()
.then(() => {
    const server = express ()


    let port = 3000;

    let options = {
        key: fs.readFileSync('some key..', 'utf-8'),
        cert: fs.readFileSync('some cert..', 'utf-8'),
    };


    server.get(
        ...
    )


    let app = https.createServer(options, server)
    .listen((port), function(){
    console.log("Express server listening on port " + port);
    });

})
.catch((ex) => {
    console.error(ex.stack)
    process.exit(1)
})

I want to deploy this as the website when someone types the URL subdomain.maindomain.com so I saved two nginx configuration files like this -

/etc/nginx/sites-available/default AND /etc/nginx/sites-available/subdomain.maindomain.com

the default file contains this

server {

    root /var/www/html;
    index index.html index.htm index.nginx-debian.html;

    server_name maindomain.com www.maindomain.com;

    location / {
            # try_files $uri $uri/ =404;
            proxy_pass http://localhost:3000;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_cache_bypass $http_upgrade;
    }

    listen [::]:443 ssl ipv6only=on; # managed by Certbot
    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/maindomain.com/fullchain.pem;$
    ssl_certificate_key /etc/letsencrypt/live/maindomain.com/privkey.pe$
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}

and the subdomain.maindomain.com file looks like this

server {
if ($host = www.subdomain.maindomain.com) {
    return 301 https://$host$request_uri;
} # managed by Certbot


if ($host = subdomain.maindomain.com) {
    return 301 https://$host$request_uri;
} # managed by Certbot


    listen 80;
    listen [::]:80;

    root /var/www/subdomain.maindomain.com/somecodefolder/;
    index index.html index.htm index.nginx-debian.html;

    server_name subdomain.maindomain.com www.subdomain.maindomain.com;


    location / {

        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
       # try_files $uri $uri/ =404;
    }

}

if I'm typing https://subdomain.maindomain.com:3000 , everything works fine, I see my website running. But when I type https://subdomain.maindomain.com (without the port number) it shows nothing. How can I get the content I want when I type just the url without the port number. I have tried many combinations, but could'nt do. someone please help i've been trying since 2 days.

Answer 1

Try to change from

proxy_pass http://localhost:3000;

Into

proxy_pass http://127.0.0.1:3000;

Answer 2

Try with other applications in order to validate if something is wrong in your application.

Configure nginx to use domain instead ports are not complex. Just add https configurations but the main configurations will be the same.

Steps

• npm install
• node main_domain.js
• node subdomain.js
• Check if webs are working:

• Add the following lines to your /etc/hosts. This will help us to use domains without enterprise web hosting company register.

127.0.0.1 maindomain.com
127.0.0.1 subdomain.maindomain.com

• Create a file in /etc/nginx/conf.d called maindomain.com.conf or whatever you want but with .conf

server {
    listen 80;
    server_name maindomain.com;
    
    location / {
        proxy_pass http://localhost:3000/;
    }
}

• Create a file in /etc/nginx/conf.d called conf.d/subdomain.maindomain.com.conf or whatever you want but with .conf

server {
    listen 80;
    server_name subdomain.maindomain.com;
    
    location / {
        proxy_pass http://localhost:3001/;
    }
}

• Restart the nginx

service nginx restart

• And now, you could use a domain instead ip:port