$config = [
    'settings' => [
        'db' => [
            'db_skif' => [
                'host' => 'mysql',
                'db_name' => 'skif',
                'user' => 'root',
                'password' => 'root',
            ]
        ]
    ]
];

Registering a service

$container->set('DB_SERVICE_CONTAINER_ID', function (ContainerInterface $container) {
    $db_config = $container->get(
        'settings.db.db_skif'
    );

    return new DBServiceFactory::factoryMySQL($db_config);
});

Use DBWrapper

Set DBWrapper db service in App

DBWrapper::setDbService($container->get('DB_SERVICE_CONTAINER_ID'));