nginx 的基础语法学习，零基础学习

学习 Nginx 的主要语法和配置选项对于有效地管理和优化 Web 服务器非常重要。以下是一些关键的 Nginx 语法和概念，涵盖了基本配置、反向代理、负载均衡、缓存等方面。

基本语法

配置文件结构
- Nginx 配置文件通常位于 /etc/nginx/nginx.conf 或 /usr/local/nginx/conf/nginx.conf。
- 配置文件由多个块组成，包括 main 块、events 块、http 块、server 块和 location 块。
注释
- 使用 # 进行单行注释。
  nginx

# 这是一个注释

3.指令

指令分为简单指令和块指令。
简单指令由指令名和参数组成，以分号结尾。
```
nginx
```

worker_processes auto;

块指令由指令名和一对花括号 {} 组成，内部可以包含其他指令

nginx

events {worker_connections 1024;
}

主要配置块

main 块
- 定义全局配置。

nginx

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log notice;
pid /run/nginx.pid;

2.events 块

定义连接处理的相关参数

nginx

events {worker_connections 1024;multi_accept on;use epoll;
}

3.http 块

包含与 HTTP 请求处理相关的配置。

nginx

http {include /etc/nginx/mime.types;default_type application/octet-stream;sendfile on;keepalive_timeout 65;gzip on;server {listen 80;server_name example.com;location / {root /usr/share/nginx/html;index index.html index.htm;}}
}

4.server 块

定义虚拟主机（站点）的具体配置。

nginx

server {listen 80;server_name example.com;location / {root /usr/share/nginx/html;index index.html index.htm;}
}

5.location 块

定义 URL 路径匹配规则及对应的处理方式

nginx

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

反向代理

proxy_pass
- 将请求转发到后端服务器。

nginx

location /api/ {proxy_pass http://backend_server;
}

upstream
- 定义一组后端服务器。

nginx

upstream backend_server {server backend1.example.com;server backend2.example.com;
}

负载均衡

轮询
- 默认的负载均衡策略。

nginx

upstream backend_server {server backend1.example.com;server backend2.example.com;
}

加权轮询

根据权重分配请求。

nginx

upstream backend_server {server backend1.example.com weight=3;server backend2.example.com;
}

IP 哈希

根据客户端 IP 地址进行哈希分配。

nginx

upstream backend_server {ip_hash;server backend1.example.com;server backend2.example.com;
}

缓存

proxy_cache
- 启用反向代理缓存。

nginx

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off;server {location / {proxy_pass http://backend_server;proxy_cache my_cache;proxy_cache_valid 200 301 302 10m;proxy_cache_valid any 1m;}
}

日志记录

access_log
- 记录访问日志。

nginx

access_log /var/log/nginx/access.log main;
log_format main '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';

SSL/TLS 配置

SSL 证书
- 配置 HTTPS 支持。

nginx

server {listen 443 ssl;server_name example.com;ssl_certificate /etc/nginx/ssl/example.com.crt;ssl_certificate_key /etc/nginx/ssl/example.com.key;location / {root /usr/share/nginx/html;index index.html index.htm;}
}

示例配置

以下是一个综合示例，展示了上述大部分配置：

nginx

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log notice;
pid /run/nginx.pid;events {worker_connections 1024;multi_accept on;use epoll;
}http {include /etc/nginx/mime.types;default_type application/octet-stream;sendfile on;keepalive_timeout 65;gzip on;proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off;upstream backend_server {server backend1.example.com;server backend2.example.com;}server {listen 80;server_name example.com;location / {return 301 https://$host$request_uri;}}server {listen 443 ssl;server_name example.com;ssl_certificate /etc/nginx/ssl/example.com.crt;ssl_certificate_key /etc/nginx/ssl/example.com.key;access_log /var/log/nginx/access.log main;log_format main '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';location / {root /usr/share/nginx/html;index index.html index.htm;}location /api/ {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;proxy_set_header X-Forwarded-Proto $scheme;proxy_cache my_cache;proxy_cache_valid 200 301 302 10m;proxy_cache_valid any 1m;}location ~ \.php$ {fastcgi_pass unix:/var/run/php-fpm.sock;fastcgi_index index.php;fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;include fastcgi_params;}}
}