Split keystone away from heat collector

This will help segregate the changes as we abstract away details of
keystone such as caching the tokens.

Change-Id: I81ccb17658e5c9fa349fb183240f901d61b1fa93
Related-Bug: #1321437

os_collect_config/heat.py

@@ -18,6 +18,7 @@ from oslo.config import cfg
 
 from openstack.common import log
 from os_collect_config import exc
+from os_collect_config import keystone
 
 CONF = cfg.CONF
 logger = log.getLogger(__name__)
@@ -67,11 +68,12 @@ class Collector(object):
             raise exc.HeatMetadataNotConfigured
 
         try:
-            ks = self.keystoneclient.Client(
+            ks = keystone.Keystone(
                 auth_url=CONF.heat.auth_url,
                 user_id=CONF.heat.user_id,
                 password=CONF.heat.password,
-                project_id=CONF.heat.project_id)
+                project_id=CONF.heat.project_id,
+                keystoneclient=self.keystoneclient).client
             endpoint = ks.service_catalog.url_for(
                 service_type='orchestration', endpoint_type='publicURL')
             logger.debug('Fetching metadata from %s' % endpoint)

os_collect_config/keystone.py

@@ -0,0 +1,41 @@
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from keystoneclient.v3 import client as ks_keystoneclient
+
+
+class Keystone(object):
+    '''A keystone wrapper class.
+
+    This wrapper is used to encapsulate any keystone related operations
+    os-collect-config may need to perform. Eventually this will be used
+    to implement memoization to reuse auth references stored on disk.
+    '''
+    def __init__(self, auth_url, user_id, password, project_id,
+                 keystoneclient=None):
+        '''Initialize Keystone wrapper.
+
+        @param string auth_url   auth_url for keystoneclient
+        @param string user_id    user_id for keystoneclient
+        @param string project_id project_id for keystoneclient
+        @param object keystoneclient optional keystoneclient implementation.
+                                     Uses keystoneclient.v3 if unspecified.
+        '''
+        if not keystoneclient:
+            keystoneclient = ks_keystoneclient
+        self.client = keystoneclient.Client(
+            auth_url=auth_url,
+            user_id=user_id,
+            password=password,
+            project_id=project_id)