Check for the required PHP-LDAP functions.

Author: Adambean

README.md

@@ -33,8 +33,9 @@ Requirements for running this tool from a management station:
 
 * Any system that can run PHP-CLI will do. (Even Windows.)
 * [PHP](https://www.php.net) version 7.0 or later: Available to most Linux distributions via `apt-get` or `yum`. You don't need anything web related, but you will need the command line interface.
+* [PHP's LDAP functions](http://php.net/manual/en/book.ldap.php): Usually installed with PHP as standard, but the LDAP module/functions may not be enabled by default.
 * [Composer](https://getcomposer.org/): Available to most Linux distributions via `apt-get` or `yum`, or manually download it as `composer.phar` alongside this tool.
-* LDAP instance: Used for Gitlab's authentication. It can (likely) be Microsoft Active Directory, OpenLDAP, 389-DS (including FreeIPA), and likely any other LDAP system, though **most of my testing is using a 389-DS instance**.
+* LDAP instance: Used for Gitlab's authentication. It can (likely) be Microsoft Active Directory, OpenLDAP, 389-DS (including FreeIPA), and any other LDAP system, though **most of my testing is with 389-DS (without FreeIPA)**.
 * [Gitlab community edition](https://gitlab.com/gitlab-org/gitlab-ce/): This must be configured to authenticate against an LDAP instance already.
 
 ## Installing

src/LdapSyncCommand.php

@@ -48,6 +48,21 @@ public function execute(InputInterface $input, OutputInterface $output): ?int
             $this->logger->warning("Dry run enabled: No changes will be persisted.");
         }
 
+        foreach([
+            "ldap_connect",
+            "ldap_bind",
+            "ldap_set_option",
+            "ldap_errno",
+            "ldap_error",
+            "ldap_search",
+            "ldap_get_entries",
+        ] as $ldapFunction) {
+            if (!function_exists($ldapFunction)) {
+                $this->logger->critical(sprintf("PHP-LDAP function \"%s\" does not exist.", $ldapFunction));
+                return 1;
+            }
+        }
+
 
 
         // Load configuration