Not authorized when logout and creating instance

Add TOKEN_DELETE_DISABLED to the settings so when can customize
the revocation of tokens on user logout or switch. This solves an
issue when a user launches a long running operation and then logs off
resulting in an error if the operation tries to validate the token

Change-Id: Ic693c563e028081d87b6447b95ac94608da2dafb
Closes-Bug: 1599870

openstack_auth/utils.py

@@ -143,6 +143,10 @@ def get_keystone_client():
         return client_v3
 
 
+def is_token_deletion_disabled():
+    return getattr(settings, 'TOKEN_DELETION_DISABLED', False)
+
+
 def is_websso_enabled():
     """Websso is supported in Keystone version 3."""
     websso_enabled = getattr(settings, 'WEBSSO_ENABLED', False)

openstack_auth/views.py

@@ -178,6 +178,8 @@ def logout(request, login_url=None, **kwargs):
 
 def delete_token(endpoint, token_id):
     """Delete a token."""
+    if utils.is_token_deletion_disabled():
+        return
     try:
         endpoint, __ = utils.fix_auth_url_version_prefix(endpoint)