Try getting old service type if session used

If set up old sahara service type in keystone service catalog
(data_processing) then if you use keystone session for auth,
saharaclient do not checks old service type.
This patch fixes this problem.

Change-Id: I148c0f59fde791c1c1cff63ea27fd6d489744ce1
Closes-bug: #1447797

saharaclient/api/client.py

@@ -76,10 +76,14 @@ class Client(object):
                 verify = cacert
 
             session = keystone_session.Session(verify=verify)
-            service_type = self._determine_service_type(session,
-                                                        auth,
-                                                        service_type,
-                                                        endpoint_type)
+
+        if not auth:
+            auth = session.auth
+
+        service_type = self._determine_service_type(session,
+                                                    auth,
+                                                    service_type,
+                                                    endpoint_type)
 
         kwargs['user_agent'] = USER_AGENT
         kwargs.setdefault('interface', endpoint_type)

saharaclient/tests/unit/nova/test_shell.py

@@ -353,15 +353,14 @@ class ShellTestKeystoneV3(ShellTest):
             ''
         ])
 
-        mock_session_class_name = 'keystoneclient.adapter.LegacyJsonAdapter'
+        mock_get_service_type_method_name = (
+            'saharaclient.api.client.Client._determine_service_type')
         mock_job_executions_class_name = (
             'saharaclient.api.job_executions.JobExecutionsManager')
 
-        with mock.patch(mock_session_class_name) as mock_session:
+        with mock.patch(mock_get_service_type_method_name) as mock_st:
             with mock.patch(mock_job_executions_class_name):
-                ms = mock_session.return_value
-                ms.session.get_endpoint.return_value = 'http://no.where'
-
+                mock_st.return_value = 'data-processing'
                 self.make_env()
                 stdout, stderr = self.shell('job-list')
                 self.assertEqual((stdout + stderr), expected)