Raise 409 when rescuing instance in RESCUE mode

fixes bud #940581

Change-Id: I8c6b600d36a35ef4e32f35b888f8f2eb8effebcd

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

@@ -17,6 +17,7 @@
 import webob
 from webob import exc
 
+from nova.api.openstack import common
 from nova.api.openstack import extensions as exts
 from nova.api.openstack import wsgi
 from nova import compute
@@ -56,7 +57,12 @@ class RescueController(wsgi.Controller):
             password = utils.generate_password(FLAGS.password_length)
 
         instance = self._get_instance(context, id)
-        self.compute_api.rescue(context, instance, rescue_password=password)
+        try:
+            self.compute_api.rescue(context, instance,
+                                    rescue_password=password)
+        except exception.InstanceInvalidState as state_error:
+            common.raise_http_conflict_for_instance_invalid_state(state_error,
+                                                                  'rescue')
         return {'adminPass': password}
 
     @wsgi.action('unrescue')

nova/api/openstack/extensions.py

@@ -301,6 +301,8 @@ def wrap_errors(fn):
     def wrapped(*args, **kwargs):
         try:
             return fn(*args, **kwargs)
+        except webob.exc.HTTPException:
+            raise
         except Exception:
             raise webob.exc.HTTPInternalServerError()
     return wrapped

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

@@ -17,6 +17,7 @@ import json
 import webob
 
 from nova import compute
+from nova import exception
 from nova import flags
 from nova import test
 from nova.tests.api.openstack import fakes
@@ -68,6 +69,21 @@ class RescueTest(test.TestCase):
         resp_json = json.loads(resp.body)
         self.assertEqual(FLAGS.password_length, len(resp_json['adminPass']))
 
+    def test_rescue_of_rescued_instance(self):
+        body = dict(rescue=None)
+
+        def fake_rescue(*args, **kwargs):
+            raise exception.InstanceInvalidState('fake message')
+
+        self.stubs.Set(compute.api.API, "rescue", fake_rescue)
+        req = webob.Request.blank('/v2/fake/servers/test_inst/action')
+        req.method = "POST"
+        req.body = json.dumps(body)
+        req.headers["content-type"] = "application/json"
+
+        resp = req.get_response(fakes.wsgi_app())
+        self.assertEqual(resp.status_int, 409)
+
     def test_unrescue(self):
         body = dict(unrescue=None)
         req = webob.Request.blank('/v2/fake/servers/test_inst/action')