nginx用途和配置实践
Nginx是什么？
“Nginx 是一款轻量级的 HTTP 服务器，采用事件驱动的异步非阻塞处理方式框架，这让其具有极好的 IO 性能，时常用于服务端的反向代理和负载均衡。”
nginx的主要用途：动静分离，反向代理，正向代理，负载均衡。
动静分离
配置反向代理
配置一个简单的反向代理是很容易的，代码如下：
server {
listen 8080;
server_name localhost;
location / {
root html; # Nginx默认值
index index.html index.htm;
}
proxy_pass http://localhost:8000; # 反向代理配置，请求会被转发到8000端口
}
反向代理的表现很简单。那上面的代码块来说，其实就是向nginx请求localhost:8080跟请求 http://localhost:8000 是一样的效果。（跟代购的原理一样）
正向代理
比如vpn：
负载均衡
# 负载均衡：设置domain
upstream domain {
server localhost:8000;
server localhost:8001;
}
server {
listen 8080;
server_name localhost;
location / {
# root html; # Nginx默认值
# index index.html index.htm;
proxy_pass http://domain; # 负载均衡配置，请求会被平均分配到8000和8001端口
proxy_set_header Host $host:$server_port;
}
}
安装
以mac为例：
#安装
brew install nginx
#查看nginx的配置信息，如下命令
brew info nginx
默认静态资源位置：/opt/homebrew/var/www
默认nginx文件位置：/opt/homebrew/etc/nginx/nginx.conf
如何配置nginx？
（一）http > server > location
nginx配置结构分为三层 http > server > location http 包含一到多个server， server包含一到多个location 配置项的优先级分别是location, server, http
举例：
http {
...
access_log /var/logs/nginx/nginx.log;
server {
server_name A;
...
access_log /var/logs/nginx/serverA/nginx.log;
location / {
...
access_log /var/logs/nginx/serverA/localtion/nginx.log;
}
}
}
匹配到server A，localtion /时日志会记录到 /var/logs/nginx/serverA/localtion/nginx.log;
匹配到server A 其他location时日志会记录到/var/logs/nginx/serverA/nginx.log
默认请求日志记录到 /var/logs/nginx/nginx.log;
（二）location优先级说明
location = / {
[ configuration A ]
}
location / {
[ configuration B ]
}
location /documents/ {
[ configuration C ]
}
location ^~ /images/ {
[ configuration D ]
}
location ~* .(gif|jpg|jpeg)$ {
[ configuration E ]
}
-
The “/” request will match configuration A,
-
the “/index.html” request will match configuration B,
-
the “/documents/document.html” request will match configuration C,
-
the “/images/1.gif” request will match configuration D,
-
the “/documents/1.jpg” request will match configuration E.
-
The “@” prefix defines a named location. Such a location is not used for a regular request processing, but instead used for request redirection. They cannot be nested, and cannot contain nested locations.
优先级规则
-
（=）的优先级最高
-
匹配(^~)优先级次之。不支持正则表达式。如果有多个location匹配的话，则使用表达式最长的那个
-
正则表达式类型（~ ~*）的优先级次之
-
常规字符串匹配，如果有多个location匹配的话，则使用表达式最长的那个
小结
-
nginx配置分三层结构，层级越深配置优先级越高
-
location 是否以/结尾和当前访问的url影响着是否301跳转
-
proxy_pass是否以/结尾影响实际访问的url是否包含location配置的前缀
静态资源压缩
可以设置在http\server、location任意一级
gzip on;
gzip_comp_level 5;
gzip_min_length 1k;
gzip_buffers 4 16k;
gzip_proxied any;
gzip_vary on;
gzip_types
application/javascript
application/x-javascript
text/javascript
text/css
text/xml
application/xhtml+xml
application/xml
application/atom+xml
application/rdf+xml
application/rss+xml
application/geo+json
application/json
application/ld+json
application/manifest+json
application/x-web-app-manifest+json
image/svg+xml
text/x-cross-domain-policy;
gzip_static on;
gzip_disable "MSIE [1-6].";
缓存
location ~ .*.(?:js|css|gif|jpg|png|svg)$ {
add_header Cache-Control max-age=31536000;
add_header Access-Control-Allow-Origin *;
add_header Access-Control-Allow-Methods 'GET, POST, OPTIONS';
add_header Access-Control-Allow-Headers 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization';
root /usr/share/nginx/html;
try_files $uri $uri/ /index.html;
}
