Nginx 基础

Nginx 是一个开源、轻量级、高性能的 Web 服务器，也用作 HTTP/HTTPS 的反向代理服务器、负载均衡器和 HTTP 缓存。

一、安装方式

方式一：yum 安装

适用于 CentOS / RHEL 7+：

yum install -y epel-release
yum install -y nginx
systemctl start nginx
systemctl enable nginx

方式二：源码编译安装

# 1. 安装依赖
yum install -y gcc pcre-devel zlib-devel

# 2. 创建运行用户
useradd -M -s /sbin/nologin nginx

# 3. 下载解压
wget http://nginx.org/download/nginx-1.24.0.tar.gz
tar -axf nginx-1.24.0.tar.gz
cd nginx-1.24.0

# 4. 编译安装
./configure --prefix=/usr/local/nginx --user=nginx --group=nginx
make && make install

# 5. 启动
/usr/local/nginx/sbin/nginx

路径优化与开机自启：

export PATH="/usr/local/nginx/sbin:$PATH"
echo "/usr/local/nginx/sbin/nginx" >> /etc/rc.d/rc.local
chmod +x /etc/rc.d/rc.local

二、配置文件结构

核心文件

nginx.conf 基本结构

worker_processes  1;               # 全局块

events {
    worker_connections  1024;       # events 块
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    upstream backend {              # 后端服务器组
        server 192.168.1.10:8080;
    }

    server {                        # server 块（虚拟主机）
        listen       80;
        server_name  localhost;

        location / {                # location 块
            root   html;
            index  index.html;
        }
    }
}

三、基础命令

nginx                # 启动
nginx -s stop        # 停止
nginx -s reload      # 重载配置（不中断服务）
nginx -t             # 检查配置语法
nginx -V             # 查看版本与编译参数

四、虚拟主机

server {
    listen       80;
    server_name  www.a.com;
    location / {
        root   /var/www/a;
        index  index.html;
    }
}

server {
    listen       80;
    server_name  www.b.com;
    location / {
        root   /var/www/b;
        index  index.html;
    }
}

五、Location 匹配规则

匹配优先级

优先级从高到低：
1.  =       精确匹配         location = /abc
2.  ^~      前缀优先匹配      location ^~ /static/
3.  ~/~*    正则匹配          location ~ \.php$
4.  无前缀  普通前缀匹配      location /abc

root 与 alias 区别

# root：URI 追加到目录后
location /images/ {
    root /var/www/html;
}
# 请求 /images/logo.png → /var/www/html/images/logo.png

# alias：替换匹配路径
location /images/ {
    alias /var/data/photos/;
}
# 请求 /images/logo.png → /var/data/photos/logo.png

六、反向代理

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

    location / {
        proxy_pass http://127.0.0.1:8080;
        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;
    }
}

常用参数：

七、负载均衡

upstream backend {
    # 加权轮询
    server 192.168.1.10:8080 weight=3;
    server 192.168.1.11:8080 weight=2;
    server 192.168.1.12:8080 weight=1;
}

server {
    listen 80;
    location / {
        proxy_pass http://backend;
    }
}

算法：

健康检查：

upstream backend {
    server 192.168.1.10:8080 max_fails=3 fail_timeout=30s;
    server 192.168.1.11:8080 max_fails=3 fail_timeout=30s;
}

• max_fails=3：连续失败 3 次认为不可用
• fail_timeout=30s：30 秒内不再转发

八、HTTPS

server {
    listen 443 ssl;
    server_name example.com;

    ssl_certificate     /etc/nginx/ssl/example.com.pem;
    ssl_certificate_key /etc/nginx/ssl/example.com.key;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         HIGH:!aNULL:!MD5;

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

# HTTP 跳转 HTTPS
server {
    listen 80;
    server_name example.com;
    return 301 https://$host$request_uri;
}

九、PHP 解析（FastCGI）

server {
    listen 80;
    root  /var/www/html;

    location / {
        index index.php index.html;
    }

    location ~ \.php$ {
        fastcgi_pass unix:/var/run/php-fpm/www.sock;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;
    }
}

十、与 Tomcat 配合

upstream tomcat {
    server 127.0.0.1:8080;
    server 127.0.0.1:8081;
}

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

    # 静态资源 Nginx 直接处理
    location /static/ {
        root /var/www/app;
        expires 7d;
    }

    # 动态请求转发 Tomcat
    location / {
        proxy_pass http://tomcat;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

十一、配置速查

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