Fix creating user in keystone v3 wrapper

A "member" role should be granted to newly created user if
version 3 of keystone is used. Name of this role is different
in different clouds. In devstack clouds it is "Member" and in
MOS clouds it is "_member_".
Assing first role with "member" string in role's name.

Change-Id: I197df429b19bd625f75223207ddb3cee5caff828
Closes-Bug: #1443367

rally/benchmark/wrappers/keystone.py

@@ -19,6 +19,10 @@ import collections
 from keystoneclient import exceptions
 import six
 
+from rally.common import log as logging
+
+
+LOG = logging.getLogger(__name__)
 
 Project = collections.namedtuple("Project", ["id", "name", "domain_id"])
 User = collections.namedtuple("User",
@@ -179,8 +183,15 @@ class KeystoneV3Wrapper(KeystoneWrapper):
                     domain_name="Default"):
         domain_id = self._get_domain_id(domain_name)
         user = self.client.users.create(name=username, password=password,
-                                        email=email, domain=domain_id,
-                                        default_project=project_id)
+                                        default_project=project_id,
+                                        email=email, domain=domain_id)
+        for role in self.client.roles.list():
+            if "member" in role.name.lower():
+                self.client.roles.grant(role.id, user=user.id,
+                                        project=project_id)
+                break
+        else:
+            LOG.warning("Unable to set member role to created user.")
         return KeystoneV3Wrapper._wrap_v3_user(user)
 
     def delete_user(self, user_id):

tests/unit/benchmark/wrappers/test_keystone.py

@@ -165,6 +165,9 @@ class KeystoneV3WrapperTestCase(test.TestCase, KeystoneWrapperTestBase):
         self.assertFalse(hasattr(result[0], "extra_field"))
 
     def test_create_user(self):
+        fake_role = mock.MagicMock(id="fake_role_id")
+        fake_role.name = "__member__"
+        self.client.roles.list.return_value = [fake_role]
         self.client.users.create.return_value = mock.MagicMock(
             id="fake_user_id")