Nginx配置与优化

Nginx简介

Nginx是一个高性能的HTTP和反向代理服务器，以其高并发、低内存消耗著称。

安装Nginx

# Ubuntu/Debian
sudo apt-get update
sudo apt-get install nginx

# CentOS/RHEL
sudo yum install epel-release
sudo yum install nginx

# 启动
sudo systemctl start nginx
sudo systemctl enable nginx

核心配置

主配置文件

# /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;
    
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent"';
    
    access_log /var/log/nginx/access.log main;
    
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    
    gzip on;
    gzip_types text/plain text/css application/json application/javascript;
    
    include /etc/nginx/conf.d/*.conf;
}

虚拟主机

# /etc/nginx/conf.d/myapp.conf
server {
    listen 80;
    server_name myapp.example.com;
    
    root /var/www/myapp;
    index index.html index.php;
    
    location / {
        try_files $uri $uri/ /index.html;
    }
    
    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php-fpm.sock;
    }
    
    location ~ /\.ht {
        deny all;
    }
}

反向代理

server {
    listen 80;
    server_name api.example.com;
    
    location / {
        proxy_pass http://127.0.0.1:3000;
        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;
    }
}

HTTPS配置

server {
    listen 443 ssl http2;
    server_name myapp.example.com;
    
    ssl_certificate /etc/nginx/ssl/cert.pem;
    ssl_certificate_key /etc/nginx/ssl/key.pem;
    
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers HIGH:!aNULL:!MD5;
    ssl_prefer_server_ciphers on;
    
    # HSTS
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    
    location / {
        proxy_pass http://127.0.0.1:3000;
    }
}

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

负载均衡

upstream backend {
    least_conn;
    server 192.168.1.10:8080;
    server 192.168.1.11:8080;
    server 192.168.1.12:8080 backup;
}

server {
    listen 80;
    server_name myapp.example.com;
    
    location / {
        proxy_pass http://backend;
    }
}

负载均衡算法

算法	说明
轮询	默认
least_conn	最少连接
ip_hash	IP哈希
hash	自定义哈希

性能优化

连接优化

events {
    worker_connections 4096;
    use epoll;
    multi_accept on;
}

Gzip压缩

gzip on;
gzip_vary on;
gzip_proxied any;
gzip_comp_level 6;
gzip_types text/plain text/css application/json application/javascript text/xml;

缓存配置

location ~* \.(jpg|jpeg|png|gif|ico|css|js)$ {
    expires 30d;
    add_header Cache-Control "public, no-transform";
}

实践：部署前端应用

server {
    listen 80;
    server_name frontend.example.com;
    
    root /var/www/frontend;
    index index.html;
    
    # 静态资源缓存
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
    
    # API代理
    location /api/ {
        proxy_pass http://127.0.0.1:3000/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
    
    # SPA路由
    location / {
        try_files $uri $uri/ /index.html;
    }
}

测试和调试

# 测试配置
nginx -t

# 重新加载配置
nginx -s reload

# 查看错误日志
tail -f /var/log/nginx/error.log

总结

Nginx是Web架构的核心组件。掌握其配置和优化技巧，可以构建高性能、高可用的Web服务。