'Sets the auto-delete flag for a volume attached to a node.
:param  volume: Volume object to auto-delete
:type   volume: :class:`StorageVolume`
:param   ex_node: Node object to auto-delete volume from
:type    ex_node: :class:`Node`
:keyword auto_delete: Flag to set for the auto-delete value
:type    auto_delete: ``bool`` (default True)
:return:  True if successful
:rtype:   ``bool``'

def ex_set_volume_auto_delete(self, volume, node, auto_delete=True):

    request = ('/zones/%s/instances/%s/setDiskAutoDelete' % (node.extra['zone'].name, node.name))
    delete_params = {'deviceName': volume.name, 'autoDelete': auto_delete}
    self.connection.async_request(request, method='POST', params=delete_params)
    return True
