NGINX as a Reverse Proxy

Nginx is a web server and also can be used as a reverse proxy.

apt install nginx

First, we can disable the default virtual host that is pre-configured when Nginx is installed.

unlink /etc/nginx/sites-enabled/default

We can edit nginx.conf file in order to configure the NGINX server to act as a reverse proxy.

we can set worker_processes count based on the number of cores allocating for worker processers. Also, set worker_connections as the number of connections concurrently handled by one processor.

helloworld is a service behind the NGINX proxy with endpoint port 80. Load balancing will happen over the 2 hosts mentions there.

upstream helloworld {
    server 54.234.84.228:8080;
    server 35.173.242.196:8080;
}
server {
        listen 80;
        listen [::]:80
        access_log /var/log/nginx/reverse-access.log;
        error_log /var/log/nginx/reverse-error.log;
location / {
           proxy_pass http://helloworld;
  }
}

We can also configure the way of load balancing as follows.

• round-robin — requests to the application servers are distributed in a round-robin fashion,
• least-connected — next request is assigned to the server with the least number of active connections,
• ip-hash — a hash-function is used to determine what server should be selected for the next request (based on the client’s IP address). Therefor one client will direct to the same server.