Deprecate kvs token backend

This backend is not usable in any production environment. All OpenStack
environments will already have a SQL DB, and if someone does not want to
use the DB they can use the memcache backend.

Fixes bug 1188301 and bug 1188370

DocImpact This backend should not be mentioned in documentation, as it
is not production grade and is deprecated.

Change-Id: I41b147bcc70b79b4fc6df50b242a73cfcad33114

doc/source/configuration.rst

@@ -492,7 +492,7 @@ Each user can then change their own password with a HTTP PATCH ::
     -H "X_Auth_Token: <authtokenid>" -d '{"user": {"password": "ABCD", "original_password": "DCBA"}}'
 
 In addition to changing their password all of the users current tokens will be
-deleted (if the backend used is kvs or sql)
+deleted (if the backend used is sql)
 
 
 Inherited Role Assignment Extension

keystone/token/backends/kvs.py

@@ -17,12 +17,26 @@
 import copy
 
 from keystone.common import kvs
+from keystone.common import logging
 from keystone import exception
 from keystone.openstack.common import timeutils
 from keystone import token
 
+LOG = logging.getLogger(__name__)
+
 
 class Token(kvs.Base, token.Driver):
+    """kvs backend for tokens is deprecated.
+
+    Deprecated in Havana and will be removed in Icehouse, as this backend
+    is not production grade.
+    """
+
+    def __init__(self, *args, **kw):
+        super(Token, self).__init__(*args, **kw)
+        LOG.warn(_("kvs token backend is DEPRECATED. Use "
+                   "keystone.token.backends.sql or "
+                   "keystone.token.backend.memcache instead."))
 
     # Public interface
     def get_token(self, token_id):