Comprehensive Nginx Installation, Configuration, and Usage Guide

Before installing Nginx, ensure the CentOS 7.2 server meets four prerequisites: network connectivity, functional yum, firewalld disabled, and SELinux set to permissive. You can verify and adjust these settings with the following commands:

# View firewalld status
systemctl status firewalld.service
# Temporarily stop firewalld
systemctl stop firewalld.service
# View SELinux status
getenforce
# Temporarily set SELinux to permissive
setenforce 0

Install basic development tools using yum:

yum -y install gcc gcc-c++ autoconf pcre pcre-devel make automake
yum -y install wget httpd-tools vim

For a quick setup, the author recommends the LNMP integrated package. Download and install it with:

wget -c http://soft.vpser.net/lnmp/lnmp1.4.tar.gz && tar zxf lnmp1.4.tar.gz && cd lnmp1.4 && ./install.sh lnmp

The default installation directory is /usr/local. After installation, edit the main configuration file /usr/local/nginx/conf/nginx.conf to set basic parameters:

user  nginx;
worker_processes  4;  # usually match CPU cores
error_log  /usr/local/nginx/logs/error.log;
pid        /usr/local/nginx/logs/nginx.pid;

events {
    worker_connections  1024;
    use                epoll;
}

http {
    sendfile        on;
    keepalive_timeout  65;
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent"';
    access_log  /usr/local/nginx/logs/access.log  main;

    server {
        listen       80;
        server_name  localhost;
        location / {
            root   /usr/local/nginx/html;
            index  index.html index.htm;
        }
        error_page 500 504 /50x.html;
        location = /50x.html {
            root   /usr/local/nginx/html;
        }
    }
    # additional server blocks can be added here
}

Nginx is an open‑source, high‑performance HTTP server and reverse proxy. Its popularity stems from three main advantages:

IO multiplexing (epoll) : Handles many concurrent connections efficiently.

Lightweight design : Only core HTTP modules are built‑in; extra functionality is added via dynamic modules.

CPU affinity : Workers can be bound to specific CPU cores to reduce cache misses.

Static resource serving is configured in the http block. Example for serving images, CSS, JS, and enabling gzip compression:

http {
    sendfile        on;
    tcp_nopush      on;
    tcp_nodelay     on;

    location ~* \.(gif|jpg|jpeg|png)$ {
        gzip            on;
        gzip_http_version 1.1;
        gzip_comp_level 2;
        gzip_types      text/plain application/javascript application/x-javascript text/javascript text/css application/xml application/xml+rss image/jpeg image/gif image/png;
        root            /opt/app/code;
    }

    location ~* \.(html|htm)$ {
        expires 12h;
    }
}

Browser caching can be controlled with the expires directive, reducing server load and latency. When a resource is unchanged, the server returns a 304 Not Modified response based on ETag and Last-Modified headers.

Cross‑origin resource sharing (CORS) is enabled by adding response headers in a location block:

location ~* \.(html|htm)$ {
    add_header Access-Control-Allow-Origin *;
    add_header Access-Control-Allow-Methods GET,POST,PUT,DELETE,OPTIONS;
    # add_header Access-Control-Allow-Credentials true;  # requires a specific origin
}

To prevent hotlinking of images, use the valid_referers directive and block invalid referers:

location ~* \.(jpg|gif)$ {
    valid_referers none blocked 127.0.0.1;
    if ($invalid_referer) {
        return 403;
    }
}

Nginx can act as a reverse proxy. A minimal proxy configuration looks like this:

server {
    listen 80;
    location / {
        proxy_pass http://127.0.0.1:8080/;
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_connect_timeout 30;
        proxy_send_timeout    60;
        proxy_read_timeout    60;
        proxy_buffer_size     32k;
        proxy_buffering      on;
        proxy_buffers        4 128k;
        proxy_busy_buffers_size 256k;
        proxy_max_temp_file_size 256k;
    }
}

The article concludes that the presented Nginx configurations cover installation, basic settings, static file handling, caching, CORS, anti‑hotlinking, and proxying, with future posts planned for load balancing and advanced caching techniques.