Nginx HTTP代理配置指南

Nginx作为高性能的反向代理服务器，可以轻松配置HTTP代理功能。以下是详细的配置方法：

基本HTTP代理配置

1. 最简单的HTTP代理配置：

server {
    listen 80;
    server_name proxy.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;
    }
}

关键配置指令详解

1. proxy_pass - 定义后端服务器地址

   proxy_pass http://backend_server;
   

   或带URI：

   proxy_pass http://backend_server/some/path/;
   

2. 请求头设置：

   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;
   

3. 缓冲与超时控制：

   proxy_buffering on;
   proxy_buffer_size 4k;
   proxy_buffers 8 16k;
   proxy_busy_buffers_size 32k;
   proxy_connect_timeout 60s;
   proxy_send_timeout 60s;
   proxy_read_timeout 60s;
   

高级代理配置

1. 负载均衡：

   upstream backend {
      server backend1.example.com;
      server backend2.example.com;
      server backend3.example.com;
   }
   
   server {
      location / {
          proxy_pass http://backend;
      }
   }
   

2. WebSocket代理：

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

3. SSL终止代理：

   server {
      listen 443 ssl;
      server_name proxy.example.com;
   
      ssl_certificate /path/to/cert.pem;
      ssl_certificate_key /path/to/key.pem;
   
      location / {
          proxy_pass http://backend_server;
          # 其他代理设置...
      }
   }
   

完整配置示例

http {
    upstream backend {
        server 10.0.0.1:8080;
        server 10.0.0.2:8080;
        keepalive 32;
    }

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

        # 静态文件直接由Nginx处理
        location /static/ {
            root /var/www;
            expires 30d;
        }

        # 动态请求代理到后端
        location / {
            proxy_pass http://backend;
            proxy_http_version 1.1;
            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;

            # 连接优化
            proxy_connect_timeout 60s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;
            proxy_buffering on;
            proxy_buffer_size 4k;
            proxy_buffers 8 16k;

            # 启用keepalive
            proxy_set_header Connection "";
        }
    }
}

常见问题排查

1. 502 Bad Gateway错误：

   • 检查后端服务是否运行
   • 检查proxy_pass地址是否正确
   • 增加proxy_connect_timeout值

2. 代理后获取真实客户端IP：

   proxy_set_header X-Real-IP $remote_addr;
   proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
   

3. 性能优化：

   • 启用proxy_buffering
   • 调整buffer大小
   • 使用keepalive连接

通过以上配置，Nginx可以高效地作为HTTP代理服务器使用，满足各种代理需求。