动态更改 nginx 根目录

Change nginx root directory dynamically

如何根据特定条件在不重定向的情况下动态地将 nginx 根目录更改为另一个目录?例如,如果:

$http_user_agent ~* "googlebot"

像这样

server {
    ...

    if ($allow = no) {
        set $variable "folder_1";
    }
    if ($allow = yes) {
        set $variable "folder_2";
    }
    root  /var/www/$variable;

    ...

    location / {
      ...
    }
}