Nginx Reverse Proxy

In this tutorial, we will discuss another Nginx feature. The Nginx web server has a number of sophisticated features that most specialised applications do not, like load balancing, TLS/SSL capabilities, and acceleration. Nginx HTTPS reverse proxy receives a client request, forwards it to one or more servers, and then returns the server's response to the client.

Why should you use Nginx Reverse Proxy?

Better Performance: Nginx is more efficient at analysing URLs and delivering static content files. Load balancing is a function that a Nginx reverse proxy can carry out to assist distribute client requests equally among backend servers. It also makes redundancy better. The reverse proxy switches requests to a different server in accordance with the routing policy if one server goes down.
Enhanced security: Your backend servers' first line of protection is a reverse proxy like Nginx. By setting up a reverse proxy, you may prevent anyone from discovering the identity of your backend servers. Users gain access to a secure HTTPS connection that is secured using TLS, securing their data, by encrypting the connection between the client and the Nginx reverse proxy.

How to add a domain to nginx?

1. Add reverse proxy configuration

$ sudo touch /etc/nginx/sites-available/reverse-proxy.conf

2. Open the settings file in a text editor.

$ sudo vi /etc/nginx/sites-available/reverse-proxy.conf

How to configure Nginx as a reverse proxy server?

The simplest use case of Nginx as a reverse proxy server is to listen on a specific port and forward the query to another serer, i.e, apache. Nginx's proxy pass directive enables reverse proxy capabilities.

server {
    listen 80;
    location / {
        proxy_pass http://192.168.0.2;
    }
}

Here, the nginx reverse proxy is listening on port 80 for the http server running on different IP.

You can specify the domain name which the reverse proxy responds to. Also, a single server_name can join numerous application servers through a proxy into a single unified web application by adding additional location blocks as necessary.

server {
    listen 80;
    server_name domain.com www.domain.com;
    location / {
        proxy_pass http://192.x.x.2;
    }
}

The common parameters used in Nginx configuration file with a reverse proxy configuration to tweak the working of proxy are shown in the configuration below:

• proxy_http_version - Defines the HTTP protocol version (the default is set to 1.0)
• proxy_cache_bypass - This configuration allows responses to bypass cache.
• X-Forwarded-For $proxy_add_x_forwarded_for - Defines the address of the client connected to the proxy.
• X-Real-IP $remote_addr - Contains the client IP address. It forwards the real visitor remote IP address to the proxied server.
• X-Forwarded-Host $host - Defines the original host requested by the client.
• X-Forwarded-Proto $scheme - If defined in an HTTPS server block, the HTTP responses from the proxied server are rewritten to HTTPS.
• X-Forwarded-Port $server_port - Defines the original port requested by the client.

server {
        listen 80;
        listen [::]:80;

        access_log /var/log/nginx/reverse-access.log;
        error_log /var/log/nginx/reverse-error.log;

        server_name domain.com www.domain.com;


        location / {
                    proxy_pass http://127.0.0.1:8080;
                    proxy_http_version  1.1;
                    proxy_cache_bypass  $http_upgrade;

                    proxy_set_header Host              $host;
                    proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
                    proxy_set_header X-Real-IP         $remote_addr;
                    proxy_set_header X-Forwarded-Host  $host;
                    proxy_set_header X-Forwarded-Proto $scheme;
                    proxy_set_header X-Forwarded-Port  $server_port;
  }
}

Finally, You can save the file and exit the editor.

Verify our configuration, then launch Nginx.

It is a recommended practice to test new configurations before loading them to production server because a single syntax mistake will prevent the Nginx service from running, which will prevent users from accessing your website. You can use the following command to do so.

$ sudo nginx -t -c /etc/nginx/sites-available/reverse-proxy.conf

Enable the site if no issues were discovered.

Finally, Start/Restart/Reload the server to load the changes:

$ sudo systemctl restart nginx

or

$ sudo service nginx restart