another strange backtrace on the beginning of the file:

2017-04-24 06:25:41.865101 mod_wsgi (pid=337959): Target WSGI script '/usr/bin/keystone-wsgi-admin' cannot be loaded as Python module.
2017-04-24 06:25:41.865173 mod_wsgi (pid=337959): SystemExit exception raised by WSGI script '/usr/bin/keystone-wsgi-admin' ignored.
2017-04-24 06:25:41.865211 Traceback (most recent call last):
2017-04-24 06:25:41.865233   File "/usr/bin/keystone-wsgi-admin", line 51, in <module>
2017-04-24 06:25:41.865263     application = initialize_admin_application()
2017-04-24 06:25:41.865275   File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 132, in initialize_admin_application
2017-04-24 06:25:41.865294     config_files=_get_config_files())
2017-04-24 06:25:41.865302   File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 69, in initialize_application
2017-04-24 06:25:41.865318     startup_application_fn=loadapp)
2017-04-24 06:25:41.865326   File "/usr/lib/python2.7/dist-packages/keystone/server/common.py", line 48, in setup_backends
2017-04-24 06:25:41.865340     drivers = backends.load_backends()
2017-04-24 06:25:41.865348   File "/usr/lib/python2.7/dist-packages/keystone/server/backends.py", line 69, in load_backends
2017-04-24 06:25:41.865362     token_provider_api=token.provider.Manager())
2017-04-24 06:25:41.865370   File "/usr/lib/python2.7/dist-packages/keystone/common/dependency.py", line 96, in __wrapped_init__
2017-04-24 06:25:41.865385     init(self, *args, **kwargs)
2017-04-24 06:25:41.865393   File "/usr/lib/python2.7/dist-packages/keystone/common/dependency.py", line 155, in wrapper
2017-04-24 06:25:41.865407     self.__wrapped_init__(*args, **kwargs)
2017-04-24 06:25:41.865415   File "/usr/lib/python2.7/dist-packages/keystone/token/provider.py", line 73, in __init__
2017-04-24 06:25:41.865611     super(Manager, self).__init__(CONF.token.provider)
2017-04-24 06:25:41.865625   File "/usr/lib/python2.7/dist-packages/keystone/common/manager.py", line 182, in __init__
2017-04-24 06:25:41.865739     self.driver = load_driver(self.driver_namespace, driver_name)
2017-04-24 06:25:41.865752   File "/usr/lib/python2.7/dist-packages/keystone/common/manager.py", line 73, in load_driver
2017-04-24 06:25:41.865771     invoke_args=args)
2017-04-24 06:25:41.865783   File "/usr/lib/python2.7/dist-packages/stevedore/driver.py", line 61, in __init__
2017-04-24 06:25:41.865903     warn_on_missing_entrypoint=warn_on_missing_entrypoint
2017-04-24 06:25:41.865916   File "/usr/lib/python2.7/dist-packages/stevedore/named.py", line 81, in __init__
2017-04-24 06:25:41.866012     verify_requirements)
2017-04-24 06:25:41.866025   File "/usr/lib/python2.7/dist-packages/stevedore/extension.py", line 186, in _load_plugins
2017-04-24 06:25:41.866175     verify_requirements,
2017-04-24 06:25:41.866187   File "/usr/lib/python2.7/dist-packages/stevedore/named.py", line 158, in _load_one_plugin
2017-04-24 06:25:41.866205     verify_requirements,
2017-04-24 06:25:41.866215   File "/usr/lib/python2.7/dist-packages/stevedore/extension.py", line 218, in _load_one_plugin
2017-04-24 06:25:41.866230     obj = plugin(*invoke_args, **invoke_kwds)
2017-04-24 06:25:41.866238   File "/usr/lib/python2.7/dist-packages/keystone/token/providers/fernet/core.py", line 40, in __init__
2017-04-24 06:25:41.866354     raise SystemExit(_('%(key_repo)s does not exist') % subs)
2017-04-24 06:25:41.866382 SystemExit: /etc/keystone/fernet-keys/ does not exist