How to deploy multiple NodeJS applications on different subdomains in digital ocean - node.js

Question

Hie guys, So earlier I deployed a nodejs application that run on one port but using Nginx, I can still accept requests on default HTTP/HTTPS ports and forward them to my application's port. Now I would like to deploy an admin part of the same application which was built in its own project space and is running on a lightly different port as my client application; and I would like to assign this to a subdomain.
I am running an Ubuntu distribution on Digital Ocean. How can I accomplish this?
Below is my entire nginx config:
# You should look at the following URL's in order to grasp a solid understanding
# of Nginx configuration files in order to fully unleash the power of Nginx.
# https://www.nginx.com/resources/wiki/start/
# https://www.nginx.com/resources/wiki/start/topics/tutorials/config_pitfalls/
# https://wiki.debian.org/Nginx/DirectoryStructure
#
# In most cases, administrators will remove this file from sites-enabled/ and
# leave it as reference inside of sites-available where it will continue to be
# updated by the nginx packaging team.
#
# This file will automatically load configuration files provided by other
# applications, such as Drupal or Wordpress. These applications will be made
# available underneath a path with that package name, such as /drupal8.
#
# Please see /usr/share/doc/nginx-doc/examples/ for more detailed examples.
##
# Default server configuration
#
server {
# SSL configuration
root /var/www/html;
# Add index.php to the list if you are using PHP
index index.html index.htm index.nginx-debian.html;
server_name mydomain.com www.mydomain.com;
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
proxy_pass http://localhost:5000; #whatever port your app runs on
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
# pass PHP scripts to FastCGI server
#
#location ~ \.php$ {
# include snippets/fastcgi-php.conf;
#
# # With php-fpm (or other unix sockets):
# fastcgi_pass unix:/var/run/php/php7.0-fpm.sock;
# # With php-cgi (or other tcp sockets):
# fastcgi_pass 127.0.0.1:9000;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
listen [::]:443 ssl ipv6only=on; # managed by Certbot
listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/mydomain.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/mydomain.com/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}
# Virtual Host configuration for example.com
#
# You can move that to a different file under sites-available/ and symlink that
# to sites-enabled/ to enable it.
#
server {
index index.html index.htm index.nginx-debian.html;
server_name admin.mydomain.com;
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
proxy_pass http://localhost:3000; #whatever port your app runs on
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;
}
}
#server {
# listen 80;
# listen [::]:80;
#
# server_name example.com;
#
# root /var/www/example.com;
# index index.html;
#
# location / {
# try_files $uri $uri/ =404;
# }
#}
server {
if ($host = mydomain.com) {
return 301 https://$host$request_uri;
} # managed by Certbot
listen 80 default_server; listen [::]:80 default_server;
server_name mydomain.com www.mydomain.com;
return 404; # managed by Certbot
}
My admin Node App is running on port 3000 and Client App on 5000

Answer 1

Your nginx configuration looks ok, in order to achieve the desired result, you have to add a new dns resolution for your new domain in digital ocean panel.
Add a new cname record that is an alias for your domain, as follow:
CNAME admin.mydomain.com
is an alias of mydomain.com
Digital ocean panel
Networking
DNS records
Create new record cname type
This configuration must match your current nginx configuration for the server_name atribute.