fix: make database required for challenges, skip challenge cleanup without database

prevents errors in cron

fix #182

Author: melanger

hooks/hook_cron.php

@@ -9,7 +9,6 @@
  * Hook to run a cron job.
  *
  * @param array $croninfo  Output
- * @author Dominik Baranek <baranek@ics.muni.cz>
  */
 function perun_hook_cron(&$croninfo)
 {
@@ -19,9 +18,15 @@ function perun_hook_cron(&$croninfo)
     }
     Logger::info('cron [perun]: Running cron in cron tag [' . $croninfo['tag'] . '] ');
 
-    $challengesDbCmd = new ChallengesDbCmd();
+    try {
+        $challengesDbCmd = new ChallengesDbCmd();
 
-    if (! $challengesDbCmd->deleteOldChallenges()) {
-        Logger::error('cron [perun]: Error while deleting old challenges from the database.');
+        if (! $challengesDbCmd->deleteOldChallenges()) {
+            Logger::error('cron [perun]: Error while deleting old challenges from the database.');
+        }
+    } catch (\Exception $e) {
+        Logger::info(
+            'cron [perun]: Not deleting old challenges from the database because no database is configured or an error occured: ' . $e->getMessage()
+        );
     }
 }

lib/databaseCommand/DatabaseConfig.php

@@ -32,7 +32,7 @@ private function __construct()
     {
         $configuration = Configuration::getConfig(self::CONFIG_FILE_NAME);
 
-        $this->config = $configuration->getConfigItem(self::DATABASE, null);
+        $this->config = $configuration->getConfigItem(self::DATABASE);
         $this->store = $this->config->getConfigItem(self::STORE, null);
 
         $this->whitelistTableName = $this->config->getString(self::WHITELIST_TABLE_NAME, null);