How to configure Nginx to forward requests to a different server based on hostname?

To configure Nginx to forward requests to a different server based on the hostname, you can use the server blocks feature. Here's a step-by-step guide:

Open the Nginx configuration file. The location of the file varies depending on your operating system. For example, on Ubuntu, it is typically located at /etc/nginx/nginx.conf or /etc/nginx/sites-available/default.
Inside the http block, define multiple server blocks for each hostname you want to forward requests to a different server. Here's an example:

http {
   server {
      listen 80;
      server_name example1.com;
      location / {
         proxy_pass http://server1;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
      }
   }

   server {
      listen 80;
      server_name example2.com;
      location / {
         proxy_pass http://server2;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
      }
   }
}

In each server block, replace example1.com and example2.com with the actual hostnames you want to forward requests for.
In the proxy_pass directive, specify the URL or IP address of the backend server you want to forward requests to. For example, http://server1 or http://192.168.1.100:8080.
Save the configuration file and exit the editor.
Test the Nginx configuration to make sure there are no syntax errors:

nginx -t

If the configuration test is successful, reload Nginx to apply the changes:

nginx -s reload

Now, Nginx will forward requests to the appropriate backend server based on the hostname specified in the request.