Nginx 深度解析：从原理到生产实战

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

    root /var/www/html;
    index index.html index.htm;

    # 启用 sendfile 零拷贝传输
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;

    # 静态资源长期缓存
    location ~* \.(jpg|jpeg|png|gif|ico|css|js|woff2)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        access_log off;
    }

    # Gzip 压缩
    gzip on;
    gzip_types text/plain text/css application/json application/javascript;
    gzip_min_length 1024;
    gzip_comp_level 6;
}

upstream backend_pool {
    least_conn;
    server 192.168.1.10:8080 weight=3;
    server 192.168.1.11:8080 weight=1;
    server 192.168.1.12:8080 backup;
    keepalive 32;
}

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

    location /api/ {
        proxy_pass http://backend_pool;

        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;

        proxy_connect_timeout 5s;
        proxy_send_timeout    60s;
        proxy_read_timeout    60s;

        proxy_http_version 1.1;
        proxy_set_header Connection "";
    }
}

server {
    listen 443 ssl http2;
    server_name www.example.com;

    ssl_certificate     /etc/nginx/ssl/fullchain.pem;
    ssl_certificate_key /etc/nginx/ssl/privkey.pem;

    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256;
    ssl_prefer_server_ciphers off;

    add_header Strict-Transport-Security "max-age=63072000" always;

    ssl_stapling on;
    ssl_stapling_verify on;
    resolver 8.8.8.8 1.1.1.1 valid=300s;

    ssl_session_cache   shared:SSL:10m;
    ssl_session_timeout 1d;

    location / {
        proxy_pass http://backend_pool;
    }
}

server {
    listen 80;
    server_name www.example.com;
    return 301 https://$host$request_uri;
}

server {
    # 优先级 1：精确匹配（=）
    location = /favicon.ico {
        log_not_found off;
        access_log off;
    }

    # 优先级 2：前缀匹配加 ^~ 修饰符（匹配后不再检查正则）
    location ^~ /static/ {
        root /var/www;
    }

    # 优先级 3：正则匹配区分大小写（~）
    location ~ \.php$ {
        fastcgi_pass 127.0.0.1:9000;
        include fastcgi_params;
    }

    # 优先级 4：正则匹配不区分大小写（~*）
    location ~* \.(jpg|png|gif)$ {
        expires 30d;
    }

    # 优先级 5：普通前缀匹配（最低）
    location / {
        try_files $uri $uri/ /index.html;
    }
}

limit_req_zone $binary_remote_addr zone=api_limit:10m rate=10r/s;
limit_conn_zone $binary_remote_addr zone=conn_limit:10m;

server {
    location /api/ {
        limit_req zone=api_limit burst=20 nodelay;
        limit_conn conn_limit 10;
        limit_req_status 429;
        limit_conn_status 429;

        proxy_pass http://backend_pool;
    }
}

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=10g inactive=60m use_temp_path=off;

server {
    location /api/products {
        proxy_cache my_cache;
        proxy_cache_key "$scheme$host$request_uri";
        proxy_cache_valid 200 301 10m;
        proxy_cache_valid 404 1m;
        proxy_cache_lock on;
        proxy_cache_use_stale error timeout updating;
        add_header X-Cache-Status $upstream_cache_status;

        proxy_pass http://backend_pool;
    }
}

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    location /ws/ {
        proxy_pass http://websocket_backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_read_timeout 3600s;
        proxy_send_timeout 3600s;
    }
}

user  nginx;
worker_processes auto;
worker_rlimit_nofile 65535;

error_log /var/log/nginx/error.log warn;
pid       /var/run/nginx.pid;

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

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

    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" rt=$request_time '
                    'urt=$upstream_response_time';

    access_log /var/log/nginx/access.log main buffer=32k flush=5s;

    sendfile    on;
    tcp_nopush  on;
    tcp_nodelay on;

    keepalive_timeout  65;
    keepalive_requests 1000;

    client_max_body_size   10m;
    client_body_buffer_size 128k;

    server_tokens off;

    include /etc/nginx/conf.d/*.conf;
}

upstream api_servers {
    least_conn;
    server 10.0.0.1:8080 max_fails=3 fail_timeout=30s;
    server 10.0.0.2:8080 max_fails=3 fail_timeout=30s;
    server 10.0.0.3:8080 max_fails=3 fail_timeout=30s;
    keepalive 64;
}

server {
    listen 443 ssl http2;
    server_name api.example.com;

    ssl_certificate     /etc/nginx/ssl/api.example.com.pem;
    ssl_certificate_key /etc/nginx/ssl/api.example.com.key;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_session_cache   shared:SSL:10m;

    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

    location = /health {
        access_log off;
        return 200 "OK\n";
        add_header Content-Type text/plain;
    }

    location /api/ {
        limit_req zone=api_limit burst=50 nodelay;
        limit_conn conn_limit 20;

        proxy_pass http://api_servers;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
        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;

        proxy_connect_timeout 3s;
        proxy_send_timeout    30s;
        proxy_read_timeout    30s;

        proxy_next_upstream error timeout http_500 http_502 http_503;
        proxy_next_upstream_tries 2;
    }

    location /static/ {
        root /var/www/api.example.com;
        expires 30d;
        add_header Cache-Control "public, immutable";
    }

    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
}

# 检查配置文件语法
nginx -t

# 平滑重载配置（不中断现有连接）
nginx -s reload
systemctl reload nginx

# 停止服务
nginx -s stop    # 立即停止
nginx -s quit    # 优雅退出

# 查看版本与编译模块
nginx -V

# 实时查看日志
tail -f /var/log/nginx/access.log
tail -f /var/log/nginx/error.log

# 查看实时连接状态（需 stub_status 模块）
curl http://localhost/nginx_status
# 输出示例：
# Active connections: 291
# server accepts handled requests
#  16630948 16630948 31070465
# Reading: 6 Writing: 179 Waiting: 106