From 7370b42c1e2a05e97713ce22beed8c1457976ced Mon Sep 17 00:00:00 2001
From: ralf <rb@egroupware.org>
Date: Fri, 23 Jun 2023 09:46:59 +0200
Subject: [PATCH] * ActiveDirectory: implement fail over for multiple AD
 controllers (failed controllers are blacklisted for 5min)

---
 api/src/Accounts/Ads.php | 58 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/api/src/Accounts/Ads.php b/api/src/Accounts/Ads.php
index 80ddf01ce7..60c047d4a5 100644
--- a/api/src/Accounts/Ads.php
+++ b/api/src/Accounts/Ads.php
@@ -1393,6 +1393,64 @@ class adLDAP extends \adLDAP
 		parent::__construct($options);
 	}
 
+	private string $_controller;
+
+	/**
+	 * Reimplemented to try all given AD controllers, before finally failing
+	 *
+	 * @return bool
+	 * @throws adLDAPException
+	 */
+	function connect()
+	{
+		// if no more working (not failed) controllers, try again with all of them
+		if (!($controllers = array_diff($this->domainControllers, $failed=(array)Api\Cache::getInstance(__CLASS__, 'failed'))))
+		{
+			$controllers = $this->domainControllers;
+			$failed = [];
+			Api\Cache::unsetInstance(__CLASS__, 'failed');
+		}
+		if ((float)PHP_VERSION < 8.2)
+		{
+			$shuffled = [];
+			while($controllers)
+			{
+				$shuffled[] = $controllers[$key = array_rand($controllers)];
+				unset($controllers[$key]);
+			}
+			$controllers = $shuffled;
+		}
+		else
+		{
+			$r = new \Random\Randomizer();
+			$controllers = $r->shuffleArray($controllers);
+		}
+		foreach($controllers as $this->_controller)
+		{
+			try {
+				return parent::connect();
+			}
+			catch (adLDAPException $e) {
+				$failed[] = $this->_controller;
+				Api\Cache::setInstance(__CLASS__, 'failed', $failed, 300);
+			}
+		}
+		// if none of the controllers worked, throw the exception
+		throw $e;
+	}
+
+
+
+	/**
+	 * Not so random anymore ;)
+	 *
+	 * @return string
+	 */
+	function randomController()
+	{
+		return $this->_controller ?? parent::randomController();
+	}
+
 	/**
 	 * Magic method called when object gets serialized
 	 *