What is Nginx?

Nginx is an open-source, high-performance HTTP server and reverse proxy server (middleware) developed by Igor Sysoev, commonly used for load balancing.

Key features and advantages of Nginx include:

1. High Performance: Capable of handling a large number of concurrent connections, excelling in high-concurrency scenarios.
2. Lightweight: Low resource consumption and high operational efficiency.
3. Reverse Proxy: Can forward client requests to multiple backend servers, enabling load balancing and improving system availability and scalability.
4. Static and Dynamic Separation: Effectively separates static resources (e.g., images, CSS, JavaScript files) from dynamic content (e.g., PHP, Python scripts), enhancing server performance.
5. Flexible Configuration: Supports a wide range of configuration options to meet various complex business requirements.
6. Caching Functionality: Can cache frequently accessed content, reducing server load and improving response speed.
7. High Stability: Widely tested and validated, offering excellent stability and reliability.

Due to its outstanding performance and rich feature set, Nginx is extensively used in the internet industry and has become a crucial tool for building efficient and reliable network services.

Installing Nginx

2.1 YUM Installation

According to the Nginx official website, you can first create an nginx.repo file in the /etc/yum.repos.d directory to define the Nginx repository. (If your server has the EPEL repository installed, you can directly use YUM for installation.)

vim /etc/yum.repos.d/nginx.repo

Add the following content:

[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

[nginx-mainline]
name=nginx mainline repo
baseurl=http://nginx.org/packages/mainline/centos/$releasever/$basearch/
gpgcheck=1
enabled=0
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

Install Nginx:

yum install nginx -y

Start Nginx:

systemctl start nginx

Enable Nginx to start on boot:

systemctl enable nginx

2.2 Compilation Installation

Access a new web server (this compilation installation is performed on the web2 server). Create a /nginx directory and download the source code package into it.

mkdir /nginx
cd /nginx
curl -O https://nginx.org/download/nginx-1.26.1.tar.gz

Extract the source code package:

tar xf nginx-1.26.1.tar.gz

configure is a script provided by Nginx for compilation configuration, primarily used to collect user-specified configurations and parameters. For example, users can specify the installation path, enable or disable certain modules (features), and customize the Nginx software.

Module	Function
--prefix=PATH	Specify installation path
--user=USER	Specify the username for starting worker processes
--group=GROUP	Specify the user group for starting worker processes
--with-http_ssl_module	Enable SSL functionality (not enabled by default)
--with-http_v2_module	Enable HTTP/2 module support
--with-http_v3_module	Enable HTTP/3 module support
--with-threads	Support multi-threading functionality
--with-stream	Support reverse proxy functionality
--with-http_stub_status_module	Status statistics functionality

Resolve dependency software packages:

yum install gcc pcre-devel openssl-devel -y

Configuraiton:

cd nginx-1.26.1
./configure --prefix=/usr/local/nginx-custom --user=webuser --group=webgroup --with-http_ssl_module --with-http_v2_module --with-threads --with-stream --with-http_stub_status_module

Start 2 processes for compilation (choose based on your CPU core count; select the number of processes equal to the number of cores):

make -j 2

Install the compiled binaries and configuration files to the /usr/local/nginx-custom directory:

make install

Create the user webuser:

useradd webuser -s /sbin/nologin

Modify the PATH environment variable to include the Nginx installation directory for easy access:

echo 'PATH=/usr/local/nginx-custom/sbin/:$PATH' >> /etc/profile
source /etc/profile

Start Nginx (ensure the firewall is disabled and SELinux is stopped):

/usr/local/nginx-custom/sbin/nginx

For Nginx installed via compilation, the following commands can be used:

Command	Purpose
nginx -s stop	Stop Nginx
nginx -s reload	Reload Nginx configuration

To streamline the compilation installation process, you can encapsulate the above steps into a shell script for future use.

vim install_nginx.sh

Add the following content:

#!/bin/bash

# Create directory for Nginx source code
mkdir -p /nginx

# Navigate to directory and download Nginx source package
cd /nginx
curl -O https://nginx.org/download/nginx-1.26.1.tar.gz

# Extract source package
tar xf nginx-1.26.1.tar.gz
cd nginx-1.26.1

# Resolve dependency packages
yum install gcc pcre-devel openssl-devel -y

# Configure
./configure --prefix=/usr/local/nginx-custom --user=webuser --group=webgroup --with-http_ssl_module --with-http_v2_module --with-threads --with-stream --with-http_stub_status_module

# Compile using 2 processes
make -j 2

# Install
make install

# Create user webuser
useradd webuser -s /sbin/nologin

# Update PATH environment variable
echo 'PATH=/usr/local/nginx-custom/sbin/:$PATH' >> /etc/profile
source /etc/profile

# Start Nginx
/usr/local/nginx-custom/sbin/nginx

# Disable firewall and set it not to start on boot
systemctl stop firewalld
systemctl disable firewalld

# Temporarily and permanently disable SELinux
setenforce 0
sed -i '/^SELINUX=/ s/enforcing/disabled/' /etc/sysconfig/selinux

Make the script executable and run it:

chmod +x install_nginx.sh
./install_nginx.sh

2.3 Enabling Auto-start for Compiled Nginx

Method 1: Modify /etc/rc.local Add /usr/local/nginx-custom/sbin/nginx to the end of the file. Grant executable permission to the file:

chmod +x /etc/rc.d/rc.local

Method 2: Create an nginx.service file for systemctl management

cd /usr/lib/systemd/system
vim nginx.service

Add the following content:

[Unit]
Description=nginx - high performance web server

[Service]
Type=forking
PIDFile=/usr/local/nginx-custom/logs/nginx.pid
ExecStart=/usr/local/nginx-custom/sbin/nginx -c /usr/local/nginx-custom/conf/nginx.conf
ExecReload=/bin/sh -c "/bin/kill -s HUP $(/bin/cat $PIDFile)"
ExecStop=/bin/sh -c "/bin/kill -s TERM $(/bin/cat $PIDFile)"

[Install]
WantedBy=multi-user.target

Reload the systemd configuration:

systemctl daemon-reload

Stop any previously started Nginx processes:

killall nginx

Start Nginx via systemctl:

systemctl start nginx

Enable Nginx to start on boot:

systemctl enable nginx

Differences between YUM installation and compilation installation:

• YUM Installation (yum install nginx)

  • Configuration files: /etc/nginx
  • Executable Nginx binary: /usr/sbin/nginx
  • Web directory: /usr/share/nginx/html

• Compilation Installation

  • Configuration files: /usr/local/nginx-custom/conf
  • Executable Nginx binary: /usr/local/nginx-custom/sbin
  • Web directory: /usr/local/nginx-custom/html