之前对rewrite的了解只停留在感性的url重写的层面上，对于为什么要进行重写没有体会。下面结合最近的项目时间谈谈对rewrite的认识
1. 对于rest化的url针对请求方式进行rewrite
e.g
RESTFUL uri—— http://example.com/user/$uid/photo
需求：
| 请求方式 | 期望处理 |
| GET | 获取某一张照片的信息 |
| POST | 添加照片 |
| PUT | 更新照片信息 |
| DELETE | 删除照片 |
针对上述需求完全可以用rewrite进行处理，从而实现 不同的业务请求方式可以映射到不同的后端处理逻辑中
server{
server_name example.com ;
if ( $request_method = GET ){
rewrite ^(/user/(.*)/photo)$ index.php?do=get_photo&uid=$2 break;
}
if ( $request_method = POST ){
rewrite ^(/user/(.*)/photo)$ index.php?do=add_photo&uid=$2 break;
}
if ( $request_method = PUT ){
rewrite ^(/user/(.*)/photo)$ index.php?do=update_photo&uid=$2 break;
}
if ( $request_method = DELETE ){
rewrite ^(/user/(.*)/photo)$ index.php?do=del_photo&uid=$2 break;
}
}
2. 金玉其外“败絮”其中
为前端展现优雅的url，利用rewrite从url中解析出需要的参数，映射到后端逻辑进行处理
3.“漏斗”式后台处理
不同的前端url，基于rewrite统一后端处理入口。举例说明：
图片展现的两种url：
| url | 说明 |
| http://example.com/([^/]*).jpg | 图片系统存储默认生成的url |
| http://example.com/d/(.*) | 图片系统支持用户自定义url |
小菜初始的nginx规则为：
location ~ ^/d/(.*)$ {
root ${SRC_ROOT}/apps/fnt ;
expires max;
fastcgi_cache cache_php;
set $PREFIX "";
if ( $request_method = HEAD ) {
set $PREFIX "HEAD_";
}
fastcgi_cache_key $PREFIX$1;
fastcgi_cache_valid 200 302 3d;
fastcgi_cache_valid 301 1d;
fastcgi_cache_valid any 1m;
fastcgi_cache_min_uses 1;
fastcgi_cache_use_stale error timeout invalid_header http_500;
tcp_nodelay on;
include fastcgi_params ;
fastcgi_pass 127.0.0.1:${CGI_PORT};
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME ${SRC_ROOT}/apps/fnt/index.php ;
fastcgi_param QUERY_STRING do=d&path=$1 ;
client_max_body_size 100m;
fastcgi_connect_timeout 1000s;
fastcgi_send_timeout 1000s;
fastcgi_read_timeout 1000s;
}
location ~ ^/([^/]*)\.(jpg|png|bmp|gif)$ {
root ${SRC_ROOT}/apps/fnt ;
expires max;
fastcgi_cache cache_php;
set $PREFIX "";
if ( $request_method = HEAD ) {
set $PREFIX "HEAD_";
}
fastcgi_cache_key $PREFIX$1;
fastcgi_cache_valid 200 302 3d;
fastcgi_cache_valid 301 1d;
fastcgi_cache_valid any 1m;
fastcgi_cache_min_uses 1;
fastcgi_cache_use_stale error timeout invalid_header http_500;
open_file_cache max=204800 inactive=20s;
open_file_cache_min_uses 1;
open_file_cache_valid 30s;
tcp_nodelay on;
include fastcgi_params ;
fastcgi_pass 127.0.0.1:${CGI_PORT};
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME ${SRC_ROOT}/apps/fnt/index.php ;
fastcgi_param QUERY_STRING key=$1&postfix=$2 ;
client_max_body_size 100m;
fastcgi_connect_timeout 1000s;
fastcgi_send_timeout 1000s;
fastcgi_read_timeout 1000s;
}
明眼人一眼就能看出，里面的冗余
在师傅的指导下利用rewrite进行修改如下：
location ~* ^/([^/]*)\.(jpg|png|bmp|gif)$ {
rewrite ^/([^/]*)\.(jpg|png|bmp|gif)$ /backend/?key=$1&postfix=$2 last;
}
location ~ ^/d/(.*)$ {
rewrite ^/d/(.*)$ /backend/?path=$1&do=d
}
location = /backend/ {
internal;
root ${SRC_ROOT}/apps/fnt ;
set $key $arg_path;
if ( $key = "" ){
set $key $arg_key;
}
expires max;
fastcgi_cache cache_php;
set $PREFIX "";
if ( $request_method = HEAD ){
set $PREFIX "HEAD_";
}
fastcgi_cache_key $PREFIX$1;
fastcgi_cache_valid 200 302 3d;
fastcgi_cache_valid 301 1d;
fastcgi_cache_valid any 1m;
fastcgi_cache_min_uses 1;
fastcgi_cache_use_stale error timeout invalid_header http_500;
open_file_cache max=204800 inactive=20s;
open_file_cache_min_uses 1;
open_file_cache_valid 30s;
tcp_nodelay on;
include fastcgi_params ;
fastcgi_pass 127.0.0.1:${CGI_PORT};
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME ${SRC_ROOT}/apps/fnt/index.php ;
fastcgi_param QUERY_STRING $query_string;
client_max_body_size 100m;
fastcgi_connect_timeout 1000s;
fastcgi_send_timeout 1000s;
fastcgi_read_timeout 1000s;
}
是不是清爽了许多？有木有？！