include my/path/to/core/database.php'; //it's the CI database file
$database = DatabaseManager::initDatabase();

$lumineConfig = array(
    'dialect' => 'MySQLi',
    'database' => $database->getDatabase(),
    'user' => $database->getUsername(),
    'password' => $database->getPassword(),
    'port' => '3306',
    'host' => $database->getHostname(),
    'package' => 'models',
    'addons_path' => ''
);