How to replace Base URL and Request URI in Drupal 8 depending on $_SERVER['SERVER_ADDR']?

Question

Drupal

Please tell me how to configure Drupal 8 for TLS gateway.

There is a regular site address:

https://site.ru/

For the same site, there is a secure TLS gateway that forwards the regular site address to a new address:

https://tls.site.ru/subdirectory/

The site began to open at a new address , but with incorrect links to web resources.

For example, in user forms, the action leads to the old address (both in the admin panel and in forms on the client side). Example: You need to make sure that the value of the action attribute contains the value "/subdirectory/node/1?destination=/node/1", similarly, in links to css styles and js scripts, "/subdirectory" is added to the beginning of the path.

<form action="/node/1?destination=/node/1" ...


For Drupal 7 in my /var/www/html/sites/default/settings.php this problem was solved like this:

$base_url = 'https://site.ru';  // NO trailing slash!

// URL TLS
$url_tls = 'tls.site.ru';

// URL TLS Path
$url_tls_path = '/subdirectory';

// URL TLS Gateway
$url_tls_gateway = 'https://' . $url_tls . $url_tls_path;

// Вход осуществляется по защищенному каналу или нет
$is_tls_gateway = FALSE;

// IP-адрес сервера, на котором выполняется текущий скрипт
$server_addr = $_SERVER['SERVER_ADDR'];

// IP-адрес интерфейса TLS
$ip_tls = '10.10.100.1';

if ($server_addr === $ip_tls) {

    // Заменить Base URL
    $base_url = $url_tls_gateway;

    // Заменить Request URI
    $_SERVER['REQUEST_URI'] = $url_tls_path . $_SERVER['REQUEST_URI']; // не работает в Drupal 8

    // TLS используется
    $is_tls_gateway = TRUE;
}

// Используется ли TLS Gateway
define('IS_TLS_GATEWAY', $is_tls_gateway);

In Drupal 8, $_SERVER['REQUEST_URI'] cannot be reassigned this way.

Can you please tell me how this issue is solved in Drupal 8?