Fatal error: Uncaught Error: Undefined constant PDO::MYSQL_ATTR_SSL_KEY in /usr/share/php/Icinga/Data/Db/DbConnection.php:178 Stack trace: #0 /usr/share/php/Icinga/Data/Db/DbConnection.php(80): Icinga\Data\Db\DbConnection->connect() #1 /usr/share/php/Icinga/Data/ResourceFactory.php(103): Icinga\Data\Db\DbConnection->__construct() #2 /usr/share/php/Icinga/Authentication/User/UserBackend.php(231): Icinga\Data\ResourceFactory::createResource() #3 /usr/share/php/Icinga/Authentication/AuthChain.php(246): Icinga\Authentication\User\UserBackend::create() #4 /usr/share/php/Icinga/Authentication/Auth.php(242): Icinga\Authentication\AuthChain->valid() #5 /usr/share/php/Icinga/Authentication/Auth.php(94): Icinga\Authentication\Auth->authExternal() #6 /usr/share/php/Icinga/Application/Web.php(323): Icinga\Authentication\Auth->isAuthenticated() #7 /usr/share/php/Icinga/Application/Web.php(101): Icinga\Application\Web->setupUser() #8 /usr/share/php/Icinga/Application/ApplicationBootstrap.php(416): Icinga\Application\Web->bootstrap() #9 /usr/share/php/Icinga/Application/webrouter.php(105): Icinga\Application\ApplicationBootstrap::start() #10 /usr/share/icingaweb2/public/index.php(4): require_once('...') #11 {main} thrown in /usr/share/php/Icinga/Data/Db/DbConnection.php on line 178