Fix instance evacuate with shared storage

Fixes instance evacuation problem when --on-shared-storage flag
specified. The problem occurs as the password variable ends up being
accessed before it is assigned. Also adds missing test case.

Fixes bug 1152492

Change-Id: I461c0f7fcf8835028f7529a7860fb330d1759d68

nova/api/openstack/compute/contrib/evacuate.py

@@ -53,6 +53,7 @@ class Controller(wsgi.Controller):
             on_shared_storage = utils.bool_from_str(
                                             evacuate_body["onSharedStorage"])
 
+            password = None
             if 'adminPass' in evacuate_body:
                 # check that if requested to evacuate server on shared storage
                 # password not specified

nova/tests/api/openstack/compute/contrib/test_evacuate.py

@@ -154,3 +154,29 @@ class EvacuateTest(test.TestCase):
         self.assertEqual(resp.status_int, 200)
         resp_json = jsonutils.loads(resp.body)
         self.assertEqual(CONF.password_length, len(resp_json['adminPass']))
+
+    def test_evacuate_shared(self):
+        ctxt = context.get_admin_context()
+        ctxt.user_id = 'fake'
+        ctxt.project_id = 'fake'
+        ctxt.is_admin = True
+        app = fakes.wsgi_app(fake_auth_context=ctxt)
+        uuid = self.UUID
+        req = webob.Request.blank('/v2/fake/servers/%s/action' % uuid)
+        req.method = 'POST'
+        req.body = jsonutils.dumps({
+            'evacuate': {
+                'host': 'my_host',
+                'onSharedStorage': 'True',
+            }
+        })
+        req.content_type = 'application/json'
+
+        def fake_update(inst, context, instance,
+                        task_state, expected_task_state):
+            return None
+
+        self.stubs.Set(compute_api.API, 'update', fake_update)
+
+        res = req.get_response(app)
+        self.assertEqual(res.status_int, 200)