Comment 9 for bug 1998333

Hitting same as #7, revision 42:

Done: juju config openstack-service-checks "os-credentials=volume_api_version=3" && check_cinder_service.py
Result: keystoneauth1.exceptions.catalog.EndpointNotFound: Could not find requested endpoint in Service Catalog.

Done: manually set OS_VOLUME_API_VERSION=3 && reboot && check_cinder_service.py
result: Change reverted by charm upon reboot, no change: keystoneauth1.exceptions.catalog.EndpointNotFound: Could not find requested endpoint in Service Catalog.

Done: manually set OS_VOLUME_API_VERSION=3 && check_cinder_service.py (no reboot)
Result: OK: All cinder services happy

Charms logs only indicate:
2023-09-22 11:25:08 WARNING unit.openstack-service-checks/0.config-changed logger.go:60 warnings.warn('Using keystoneclient sessions has been deprecated. '
2023-09-22 11:25:08 WARNING unit.openstack-service-checks/0.config-changed logger.go:60 /usr/lib/python3/dist-packages/keystoneauth1/adapter.py:235: UserWarning: Using keystoneclient sessions has been deprecated. Please update your software to use keystoneauth1.