location /admin/ {
            auth_basic "Secure area";
            auth_basic_user_file .htpasswd;
            error_page 404 = @admin;
    }
location @admin {
            rewrite  ^(.*)$ /admin/index.php last;
}给目录添加认证
auth_basic
但有伪静态显示404,解决方法:
https://serverfault.com/questions/808320/nginx-auth-basic-not-working-with-rewrite
