NGINX

What is NGINX

Nginx is an open-source, high-performance web server and reverse proxy server. Here's a brief description of its key functions:

• Web Server: Nginx can serve static files, such as HTML, CSS, and image files, directly to clients.
• Reverse Proxy: It can act as a reverse proxy server, managing client requests and distributing them to multiple backend servers. This is useful for load balancing and improving performance.
• Load Balancer: Nginx can function as a load balancer to distribute traffic among several backend servers, enhancing scalability and availability.
• HTTPS Management: It provides capabilities for handling the HTTPS (SSL/TLS) protocol to ensure web communication security.
• Caching: It can cache static content to reduce the load on backend servers and improve loading times.
• Mail Server: Although not its primary function, Nginx can also be used as a mail server for the IMAP/POP3 protocols.

Reverse proxy with NGINX

Servers

Using NGINX you can configure different servers, and has a default server. There are various types of configurations: we can create a specific server that contains rules only for that server or generate rules for the default server. You can use server to create a new instance of a server in Nginx.

In this example, we configure a server, and all requests directed to the subdomain example.* will be handled by this server. Additionally, we specify that it only listens on port 80 and has a maximum request size of 100 megabytes.

server { 
    listen 80;
    server_name patata.*$;
    client_max_body_size 100M;
}

Server alias

Nginx allows to create multiple aliases for a server through upstream . In the following example, we see how the server with the address backoffice:8081 is given the alias name backoffice . Additional context is provided in the example to understand where the upstream directive is placed in a configuration block.

upstream backoffice {
    server backoffice:8081;
}
 
server {
    listen 80;
    location / {
        proxy_pass http://backoffice;
    }
}

Redirection rules

Each of the redirection rules is named proxy_pass. In the following example, we will see how they are configured:

location [path name] {
    proxy_pass [redirects to path];
}
 
location /api {
    proxy_pass http://localhost:1880/;
}

If the / character is included at the end of the destination server address, Nginx is instructed to preserve the path of the incoming request and append it to the destination server address.

Example 1: if a user accesses http://example.com/some/path, and the Nginx configuration includes proxy_pass http://localhost/, the request will be redirected to http://localhost/some/path.

location /some/path {
    proxy_pass http://my_db_url/;
}

The previous rule redirects to http://my_db_url/some/path

If the / character is NOT included at the end of the destination server address, Nginx is instructed to ignore the path of the incoming request and use the destination server address as is.

Example 2: if a user accesses http://example.com/some/path, and the Nginx configuration includes proxy-pass http://localhost, the request will be redirected to http://localhost

location /some/path {
    proxy_pass http://my_db_url;
}

The previous rule redirects to http://my_db_url/

Importing configurations

In each of the Nginx configuration files, we can concatenate other configurations. This is done using the include directive. In the following example, we will see how all configuration files within the folder /etc/nginx/conf.d/_services/ whose names end in .service.conf are included.

{
    server {
        listen 80;
    }
    include /etc/nginx/conf.d/_services/*.service.conf;
}