nginx rewrite操作示例

$uri进行正则匹配，进行rewrite操作。

1，情景需求

访问下面两个URL时

http://a.b.com/20231105db704ee0d243fc237c182bb81e87bd0e_origin.jpg

http://a.b.com/image/2023/11/05/20231105db704ee0d243fc237c182bb81e87bd0e_origin.jpg

转换为

http://a.b.com/mnt/img/image/2023/11/05/20231105db704ee0d243fc237c182bb81e87bd0e_origin.jpg

2，nginx rewrite指令

http://a.b.com/20231105db704ee0d243fc237c182bb81e87bd0e_origin.jpg的转换规则：

注意这里正则匹配表达式用双引号括起来，否则会报错。

if ($uri ~* "^/[0-9]{8}.+$") {
    rewrite "^/([0-9]{4})(\d{2})(\d{2})(.*)$" https://$host/mnt/img/image/$1/$2/$3/$1$2$3$4 last;
}

http://a.b.com/image/2023/11/05/20231105db704ee0d243fc237c182bb81e87bd0e_origin.jpg的转换规则：

if ( $uri !~* ^\/mnt\/.* ) {
    rewrite ^(.*)$ https://$host/mnt/img$1 last;
}

3，这里为什么使用flag：last ？

因为还有一个location /mnt/取匹配处理rewrite后的URL，所以此处使用last，继续向下匹配location进行处理。而用break的话，会直接返回URL。

last

stops processing the current set of ngx_http_rewrite_module directives and starts a search for a new location matching the changed URI;

break

stops processing the current set of ngx_http_rewrite_module directives as with the break directive;