--- fixes: - | [:bug:`1874705`] Add a new variable WEBSSO_USE_HTTP_REFERER to facilitate WEBSSO deployments where network segmentation is used per security requirement. In this case, the controllers cannot reach other services external endpoints. Therefore, using the HTTP_REFERER to derive the Keystone endpoint in the websso view will return a timeout for requests to Keystone in cases where the external Keystone endpoint is the HTTP_REFERER. WEBSSO_USE_HTTP_REFERER defaults to True to keep inline with current functionality. When set to False the OPENSTACK_KEYSTONE_URL is used instead of the HTTP_REFERER. If OPENSTACK_KEYSTONE_URL is set to the internal Keystone endpoint the requests between Horizon and Keystone should be able to connect.