get_highest_client_server_version should work with any endpoint type: cinder-api with eventlet, uWSGI, etc. This patch is based on python-novaclient patch [1]. In a future, we can deprecate get_highest_client_server_version in flavor of keystoneauth descovery feature. [1] Icba858b496855e2ffd71b35168e8057b28236119 Closes-Bug: #1708188 Change-Id: I9acf6dc84c32b25bfe3254eb0f97248736498d32