use OpenCloud\OpenStack;
use OpenCloud\Rackspace;
use League\Flysystem\Filesystem;
use League\Flysystem\Rackspace\RackspaceAdapter as Adapter;

$client = new Rackspace(Rackspace::UK_IDENTITY_ENDPOINT, array(
    'username' => ':username',
    'apiKey' => ':password',
));

$store = $client->objectStoreService('cloudFiles', 'LON');
$container = $store->getContainer('flysystem');

$filesystem = new Filesystem(new Adapter($container));