Description of problem:

Would it be possible to backport this patch https://review.openstack.org/#/c/234578/ . During the upgrade from RHOSP 8 to RHOSP 9 we hit following problem while doing '3.4.2. Installing Aodh' at https://access.redhat.com/documentation/en/red-hat-openstack-platform/9/paged/upgrading-red-hat-openstack-platform/chapter-3-director-based-environments-performing-upgrades-to-major-versions

When running manually we hit:

# /usr/bin/aodh-api --logfile /var/log/aodh/api.log
Traceback (most recent call last):
  File "/usr/bin/aodh-api", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/site-packages/aodh/cmd/api.py", line 23, in main
    conf = service.prepare_service()
  File "/usr/lib/python2.7/site-packages/aodh/service.py", line 70, in prepare_service
    keystone_client.setup_keystoneauth(conf)
  File "/usr/lib/python2.7/site-packages/aodh/keystone_client.py", line 145, in setup_keystoneauth
    if conf[CFG_GROUP].auth_type == "password-aodh-legacy":
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2950, in __getattr__
    return self._conf._get(name, self._group)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2571, in _get
    value = self._do_get(name, group, namespace)
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 2608, in _do_get
    return convert(opt._get_from_namespace(namespace, group_name))
  File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 811, in _get_from_namespace
    dname, dgroup = opt.name, opt.group
AttributeError: 'Opt' object has no attribute 'group'

Which corresponds to https://bugs.launchpad.net/keystoneauth/+bug/1505906