使用此配置：

server {
    listen 8080;
    location / {
        if ($http_cookie ~* "mycookie") {
            proxy_set_header X-Request $request;
            proxy_pass http://localhost:8081;
        }
    }
}

我重新加载Nginx服务时出现此错误：

Reloading Nginx configuration: Nginx: [emerg] "proxy_set_header" directive is not allowed here in /etc/Nginx/conf.d/check_cookie.conf:5
Nginx: configuration file /etc/Nginx/Nginx.conf test Failed

这个配置工作正常,但它没有做我想要的：

server {
    listen 8080;
    location / {
        proxy_set_header X-Request $request;
        if ($http_cookie ~* "mycookie") {
            proxy_pass http://localhost:8081;
        }
    }
}

为什么我不能将proxy_set_header指令放在if子句中？

提前致谢！