How can I check in Drupal 8 an externally set $_COOKIE? I would like to check whether a Cookie exists, and if so, get the value. But it looks like Drupal is blind to external cookies that have not been set inside Drupal.

$mycookie = \Drupal::request()-&gt;cookies-&gt;all();


Returns an array with only the Drupal cookies, and I can see in my web browser that there are more (some that I am interested in and I can't modify he app that is creating those cookies). I remember there was a similar issue with Symfony 2 and session but I can't find it...
For external cookies please try with $_COOKIE['cookie_name'].

if (isset($_COOKIE['cookie_name'])) {
  print($_COOKIE['cookie_name']);
}


The code will print out the value of the cookie if present.

For a more specific answer please explain your question.Ty!