This also required for rhel
---- Begin output of keystone-manage pki_setup ; chown keystone -R /etc/keystone/ssl/ ----
STDOUT:
STDERR: usage: keystone-manage [db_sync|db_version|pki_setup|ssl_setup|token_flush] pki_setup
       [-h] --keystone-user KEYSTONE_USER --keystone-group KEYSTONE_GROUP
keystone-manage [db_sync|db_version|pki_setup|ssl_setup|token_flush] pki_setup: error: argument --keystone-user is required