The Versatile Nginx: A Complete Guide to Web Hosting, Reverse Proxy, Load Balancing, Streaming, and More

Nginx is one of the most versatile and efficient open-source web servers available. It offers a wide range of features that extend far beyond traditional web hosting, such as load balancing, reverse proxying, live streaming, and even acting as a mail server proxy. In this blog post, we’ll explore the most common use cases for Nginx and provide configuration examples for each.

Finding and Editing Nginx Configuration Files

To locate and edit the Nginx configuration files, follow these steps:

1. Default Paths for Nginx Configuration Files

The main configuration files for Nginx are usually located in one of the following directories, depending on your system:

Debian/Ubuntu-based Systems:

• Main configuration file: /etc/nginx/nginx.conf
• Directories for additional configurations:
  • /etc/nginx/conf.d/ (For additional configurations)
  • /etc/nginx/sites-available/ (For available sites)
  • /etc/nginx/sites-enabled/ (For enabled sites, typically symbolic links to sites-available)

Red Hat/CentOS-based Systems:

• Main configuration file: /etc/nginx/nginx.conf
• Directory for additional configurations: /etc/nginx/conf.d/

1. Web Server

One of the primary use cases of Nginx is serving static content efficiently, such as HTML, CSS, JavaScript, and images. It can handle multiple concurrent connections with minimal memory usage, making it ideal for high-traffic websites.

Configuration Example:

server {
    listen 80;
    server_name example.com;

    location / {
        root /var/www/html;
        index index.html index.htm;
    }

    location /images/ {
        root /var/www/html/assets;
    }
}

Dynamic Content via Proxy:

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://localhost:3000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

2. Reverse Proxy

Nginx can be used as a reverse proxy server to forward client requests to one or more backend servers. This helps in load balancing, improving performance, and providing a unified interface for clients.

Configuration Example:

http {
    upstream backend {
        server backend1.example.com;
        server backend2.example.com;
    }

    server {
        listen 80;
        server_name example.com;

        location / {
            proxy_pass http://backend;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }
    }
}

3. Load Balancing

Load balancing is crucial for distributing incoming network traffic across multiple servers to ensure no single server becomes a bottleneck. Nginx supports various load-balancing methods including round-robin, IP-hash, and least-connected.

Configuration Example:

http {
    upstream myapp {
        server app1.example.com;
        server app2.example.com;
        server app3.example.com;
    }

    server {
        listen 80;
        server_name example.com;

        location / {
            proxy_pass http://myapp;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }
    }
}

4. Streaming Media

Nginx can also be used to stream media content such as video or audio. It supports various streaming protocols, including HLS (HTTP Live Streaming) and RTMP (Real-Time Messaging Protocol).

Configuration Example:

rtmp {
    server {
        listen 1935;

        application live {
            live on;
            record off;
        }
    }
}

http {
    server {
        listen 80;
        server_name example.com;

        location /hls {
            types {
                application/vnd.apple.mpegurl m3u8;
                video/mp2t ts;
            }
            root /var/www/html/stream;
            add_header Cache-Control no-cache;
        }
    }
}

5. SSL Termination

Nginx can handle SSL/TLS encryption, often referred to as SSL termination. This means Nginx decrypts incoming SSL requests and forwards the unencrypted requests to backend servers.

Configuration Example:

server {
    listen 443 ssl;
    server_name example.com;

    ssl_certificate /etc/nginx/ssl/example.com.crt;
    ssl_certificate_key /etc/nginx/ssl/example.com.key;

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

6. Mail Proxy

Nginx can also be configured to act as a mail proxy server for SMTP, POP3, and IMAP protocols. This is useful for distributing mail traffic and adding additional security layers.

Configuration Example:

mail {
    server {
        listen 25;
        protocol smtp;

        smtp_auth login;
        smtp_auth plain;
        smtp_auth cram-md5;

        proxy_pass_error_message on;
        proxy_pass backend.example.com;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

Conclusion

Nginx’s versatility and performance make it an excellent choice for various use cases beyond just serving static files. Whether you're looking to set up a web server, manage traffic with a reverse proxy, balance loads, stream media, handle SSL termination, or proxy mail, Nginx has you covered. Experiment with these configurations and explore Nginx’s extensive documentation to fully leverage its capabilities.