Some more tracebacks found duringfurther debugging:

2017-04-24 11:13:41.068238 mod_wsgi (pid=494992): Exception occurred processing WSGI script '/usr/bin/keystone-wsgi-admin'.
2017-04-24 11:13:41.068272 Traceback (most recent call last):
2017-04-24 11:13:41.068303   File "/usr/bin/keystone-wsgi-admin", line 51, in <module>
2017-04-24 11:13:41.068349     application = initialize_admin_application()
2017-04-24 11:13:41.068362   File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 132, in initialize_admin_application
2017-04-24 11:13:41.068386     config_files=_get_config_files())
2017-04-24 11:13:41.068397   File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 56, in initialize_application
2017-04-24 11:13:41.068415     common.configure(config_files=config_files)
2017-04-24 11:13:41.068426   File "/usr/lib/python2.7/dist-packages/keystone/server/common.py", line 30, in configure
2017-04-24 11:13:41.068444     keystone.conf.configure()
2017-04-24 11:13:41.068454   File "/usr/lib/python2.7/dist-packages/keystone/conf/__init__.py", line 126, in configure
2017-04-24 11:13:41.068473     help='Do not monkey-patch threading system modules.'))
2017-04-24 11:13:41.068483   File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2288, in __inner
2017-04-24 11:13:41.068502     result = f(self, *args, **kwargs)
2017-04-24 11:13:41.068512   File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2478, in register_cli_opt
2017-04-24 11:13:41.068528     raise ArgsAlreadyParsedError("cannot register CLI option")
2017-04-24 11:13:41.068559 ArgsAlreadyParsedError: arguments already parsed: cannot register CLI option
2017-04-24 11:13:42.985851 mod_wsgi (pid=494991): Target WSGI script '/usr/bin/keystone-wsgi-admin' cannot be loaded as Python module.
2017-04-24 11:13:42.985900 mod_wsgi (pid=494991): Exception occurred processing WSGI script '/usr/bin/keystone-wsgi-admin'.
2017-04-24 11:13:42.985933 Traceback (most recent call last):
2017-04-24 11:13:42.985962   File "/usr/bin/keystone-wsgi-admin", line 51, in <module>
2017-04-24 11:13:42.986004     application = initialize_admin_application()
2017-04-24 11:13:42.986018   File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 132, in initialize_admin_application
2017-04-24 11:13:42.986063     config_files=_get_config_files())
2017-04-24 11:13:42.986076   File "/usr/lib/python2.7/dist-packages/keystone/server/wsgi.py", line 56, in initialize_application
2017-04-24 11:13:42.986093     common.configure(config_files=config_files)
2017-04-24 11:13:42.986103   File "/usr/lib/python2.7/dist-packages/keystone/server/common.py", line 30, in configure
2017-04-24 11:13:42.986121     keystone.conf.configure()
2017-04-24 11:13:42.986131   File "/usr/lib/python2.7/dist-packages/keystone/conf/__init__.py", line 126, in configure
2017-04-24 11:13:42.986149     help='Do not monkey-patch threading system modules.'))
2017-04-24 11:13:42.986159   File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2288, in __inner
2017-04-24 11:13:42.986178     result = f(self, *args, **kwargs)
2017-04-24 11:13:42.986187   File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2478, in register_cli_opt
2017-04-24 11:13:42.986204     raise ArgsAlreadyParsedError("cannot register CLI option")
2017-04-24 11:13:42.986231 ArgsAlreadyParsedError: arguments already parsed: cannot register CLI option