Add ability to run fakeldap in memory.

Tests speedup.

Change-Id: I6c1df5990cf2b6c45ea7cab03905c89b92749c9c

keystone/backends/ldap/fakeldap.py

@@ -123,12 +123,28 @@ def _subs(value):
 server_fail = False
 
 
+class FakeShelve(dict):
+    @classmethod
+    def get_instance(cls):
+        try:
+            return cls.__instance
+        except AttributeError:
+            cls.__instance = cls()
+            return cls.__instance
+
+    def sync(self):
+        pass
+
+
 class FakeLDAP(object):
     """Fake LDAP connection."""
 
     def __init__(self, url):
         LOG.debug("FakeLDAP initialize url=%s" % (url,))
-        self.db = shelve.open(url[7:])
+        if url == 'fake://memory':
+            self.db = FakeShelve.get_instance()
+        else:
+            self.db = shelve.open(url[7:])
 
     def simple_bind_s(self, dn, password):
         """This method is ignored, but provided for compatibility."""

keystone/test/etc/ldap.conf.template

@@ -21,7 +21,7 @@ sql_idle_timeout = 30
 backend_entities = ['Endpoints', 'Credentials',  'EndpointTemplates', 'Token', 'Service']
 
 [keystone.backends.ldap]
-ldap_url = fake://%(test_dir)s/ldap.db
+ldap_url = fake://memory
 ldap_user = cn=Admin
 ldap_password = password
 backend_entities = ['Tenant', 'User', 'UserRoleAssociation', 'Role']