'Attaches a volume to a server instance.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#attach-a-volume-to-an-instance'

def attach_volume(self, server_id, **kwargs):

    post_body = json.dumps({'volumeAttachment': kwargs})
    (resp, body) = self.post(('servers/%s/os-volume_attachments' % server_id), post_body)
    body = json.loads(body)
    self.validate_response(schema.attach_volume, resp, body)
    return rest_client.ResponseBody(resp, body)
