Mastering NGINX: A Comprehensive Guide to Installation, Configuration, and Optimization

Introduction to NGINX

NGINX is a high-performance HTTP server, reverse proxy, and IMAP/POP3 proxy server. It's known for its speed, stability, and low resource use.

Key Use Cases:

• Web server

• Reverse proxy

• Load balancing

• HTTP caching

• Media streaming

Installation of NGINX

On Ubuntu/Debian:

sudo apt update
sudo apt install nginx

On CentOS/RHEL:

sudo yum install epel-release
sudo yum install nginx

Start and Enable NGINX:

sudo systemctl start nginx
sudo systemctl enable nginx

NGINX Basic Configuration

NGINX’s configuration file is located at /etc/nginx/nginx.conf. It consists of the following basic components:

• Main Context: Global configurations.

• Events Context: Defines how NGINX handles connections.

• HTTP Context: Contains settings for web server functionalities.

• Server Blocks: Equivalent to Apache’s Virtual Hosts.

• Location Blocks: Define how requests should be processed.

Understanding Configuration Syntax

Here's a simple configuration snippet:

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

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

• listen 80: Listen on port 80 (HTTP).

• server_name: Domain name.

• location /: Define rules for handling requests to /.

• root: Root directory for the website.

• index: Default file to serve.

Server Blocks (Virtual Hosts)

Server blocks allow NGINX to handle multiple domains.

Example:

server {
    listen 80;
    server_name site1.com;

    root /var/www/site1;
    index index.html;

    location / {
        try_files $uri $uri/ =404;
    }
}

server {
    listen 80;
    server_name site2.com;

    root /var/www/site2;
    index index.html;

    location / {
        try_files $uri $uri/ =404;
    }
}

Reverse Proxy Configuration

A reverse proxy forwards client requests to another server.

Example:

server {
    listen 80;
    server_name example.com;

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

Load Balancing

NGINX supports several load balancing methods:

• Round Robin (default)

• Least Connections

• IP Hash

Example:

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

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://backend;
    }
}

Caching

NGINX can cache static and dynamic content to improve performance.

Basic caching configuration:

proxy_cache_path /data/nginx/cache levels=1:2 keys_zone=my_cache:10m max_size=10g;
server {
    location / {
        proxy_cache my_cache;
        proxy_pass http://backend;
        add_header X-Cache-Status $upstream_cache_status;
    }
}

Security Best Practices

• Restrict Access: Use IP whitelisting/blacklisting.

• Rate Limiting: Prevent DDoS attacks.

    limit_req_zone $binary_remote_addr zone=mylimit:10m rate=10r/s;
    server {
        location / {
            limit_req zone=mylimit burst=20;
        }
    }
  

• SSL/TLS Configuration: Secure your server with HTTPS.

    server {
        listen 443 ssl;
        server_name example.com;
  
        ssl_certificate /path/to/cert.pem;
        ssl_certificate_key /path/to/key.pem;
  
        location / {
            root /var/www/html;
            index index.html;
        }
    }
  

Monitoring and Logging

• Access Logs: /var/log/nginx/access.log

• Error Logs: /var/log/nginx/error.log

Modify logging configuration:

http {
    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log warn;
}

Advanced Topics

• NGINX Modules: Extend functionalities with dynamic modules.

• HTTP/2 Support: Improve performance with multiplexing and header compression.

    listen 443 ssl http2;
  

• WebSocket Proxying: Support real-time applications.

    location /ws/ {
        proxy_pass http://backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
  

Performance Tuning

• Worker Processes: Adjust based on the number of CPU cores.

    worker_processes auto;
  

• Connection Handling: Optimize for high concurrency.

    events {
        worker_connections 1024;
    }
  

Troubleshooting

• Test Configuration: Check for syntax errors.

    sudo nginx -t
  

• Reload Configuration: Apply changes without downtime.

    sudo systemctl reload nginx
  

Reference

1. NGINX Official Documentation
   https://nginx.org/en/docs/
   The official NGINX documentation, providing comprehensive details on installation, configuration, and advanced features.

2. NGINX Installation Guide
   https://nginx.org/en/linux_packages.html
   A guide for installing NGINX on various Linux distributions, including Ubuntu, Debian, CentOS, and RHEL.

3. NGINX Configuration Guide
   https://docs.nginx.com/nginx/admin-guide/basic-functionality/managing-configuration-files/
   Detailed information on managing NGINX configuration files, including contexts, server blocks, and directives.

4. NGINX Load Balancing Configuration
   https://docs.nginx.com/nginx/admin-guide/load-balancer/http-load-balancer/
   A guide on configuring load balancing with NGINX, covering various methods such as round robin, least connections, and IP hash.

5. NGINX Security Best Practices
   https://docs.nginx.com/nginx/admin-guide/security-controls/
   Best practices for securing NGINX, including rate limiting, IP access control, SSL/TLS configuration, and more.