Methods to disable Nginx cache when user is authenticated in Drupal

There are some cases we only need Nginx cache enabled for anonymous users. I can show two ways on how to disable Nginx cache when user is authenticated and enable it for anonymous users in Drupal.

Method 1: Using Cookie

This method invloves Drupal custom module to set an identifier in Cookie that a user is authenticated.

The custom module uses hook_user_login() to set "nocache=1" in Cookie if user is logged in and hook_user_logout() to set "nocache=0" if user is logged out. The codes are as follows (you can download the custom module below this article):

  
<?php
/**
 * Set a cookie for logged in users.
 */
function nginx_nocache_user_login() {
  nginx_nocache_user_cookie();
}

/**
 * Delete a cookie for logged out users.
 */
function nginx_nocache_user_logout($account) {
  nginx_nocache_user_cookie(TRUE);
}

/**
 * Helper to set / delete a cookie for users.
 */
function nginx_nocache_user_cookie($delete = FALSE) {
  $params = session_get_cookie_params();
  if ($delete) {
    $expire = REQUEST_TIME - 3600;
    $val = 0;
  }
  else {
    $expire = $params['lifetime'] ? REQUEST_TIME + $params['lifetime'] : 0;
    $val = 1;
  }
  setcookie('nocache', $val, $expire, $params['path'], $params['domain'], FALSE, $params['httponly']);
}
?>
  

As for our Nginx configuration, we can now tell Nginx if the value "nocache" in Cookie is set disable the cache otherwise enable the cache:

  
proxy_no_cache      $cookie_nocache;
proxy_cache_bypass  $cookie_nocache;
  

Method 2: Using Session

We will only work on Nginx configuration for this method. When a user is logged in we can observe that a session ID is created that is something like this:

  
SESS35ff8c61bdd320e6efaf605888616911=OteOH_VuieYK9_Y-culzTEsQJevDfIjkUC80d-aO8B
  

We can use this as identifier if a user is authenticated or anonymous. Our Nginx configuration can have this:

  
map $http_cookie $no_cache {
    default 0;
    ~SESS 1; # PHP session
}
proxy_no_cache      $no_cache;
proxy_cache_bypass  $no_cache;