events {}

http {
  upstream backend_servers {
    server whatsapp-rest-1:1321;
    # server whatsapp-rest-2:1321;
    # server whatsapp-rest-3:1321;
  }

  server {
    listen 80;

    location / {
      proxy_pass http://backend_servers;
      proxy_set_header Host $host;
      proxy_set_header X-Real-IP $remote_addr;
    }
  }
}