Fix variable referenced before assginment in vmwareapi code.

Add unitests for VMwareapi vm_util.
fix bug #1177689

Change-Id: If16109ee626c197227affba122c2e4986d92d2df

nova/tests/test_vmwareapi_vm_util.py

@@ -0,0 +1,55 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+#
+# Copyright 2013 Canonical Corp.
+# All Rights Reserved.
+#
+#    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 nova import exception
+from nova import test
+from nova.virt.vmwareapi import fake
+from nova.virt.vmwareapi import vm_util
+
+
+class fake_session(object):
+    def __init__(self, ret=None):
+        self.ret = ret
+
+    def _call_method(self, *args):
+        return self.ret
+
+
+class VMwareVMUtilTestCase(test.TestCase):
+    def setUp(self):
+        super(VMwareVMUtilTestCase, self).setUp()
+
+    def tearDown(self):
+        super(VMwareVMUtilTestCase, self).tearDown()
+
+    def test_get_datastore_ref_and_name(self):
+        result = vm_util.get_datastore_ref_and_name(
+            fake_session([fake.Datastore()]))
+
+        self.assertEquals(result[1], "fake-ds")
+        self.assertEquals(result[2], 1024 * 1024 * 1024)
+        self.assertEquals(result[3], 1024 * 1024 * 500)
+
+    def test_get_datastore_ref_and_name_without_datastore(self):
+
+        self.assertRaises(exception.DatastoreNotFound,
+                vm_util.get_datastore_ref_and_name,
+                fake_session(), host="fake-host")
+
+        self.assertRaises(exception.DatastoreNotFound,
+                vm_util.get_datastore_ref_and_name,
+                fake_session(), cluster="fake-cluster")

nova/virt/vmwareapi/vm_util.py

@@ -553,7 +553,6 @@ def get_datastore_ref_and_name(session, cluster=None, host=None):
                                 "Datastore", data_store_mors,
                                 ["summary.type", "summary.name",
                                  "summary.capacity", "summary.freeSpace"])
-
     for elem in data_stores:
         ds_name = None
         ds_type = None
@@ -570,8 +569,6 @@ def get_datastore_ref_and_name(session, cluster=None, host=None):
                 ds_free = prop.val
         # Local storage identifier
         if ds_type == "VMFS" or ds_type == "NFS":
-            data_store_name = ds_name
-            return elem.obj, data_store_name, ds_cap, ds_free
+            return elem.obj, ds_name, ds_cap, ds_free
 
-    if data_store_name is None:
         raise exception.DatastoreNotFound()