Ensure the correct error message is displayed

When a untranslated error message pass through the translation pecan
hook, the previous translated error is send to the client.

This patch fix that by reseting the "translatable_error" of the
translation pecan hook before each request.

Change-Id: Icee79cf09fd696655048c7c0cf8a3d6706e31701
Fixes: bug #1260398

ceilometer/api/hooks.py

@@ -74,6 +74,9 @@ class TranslationHook(hooks.PecanHook):
         self.local_error = threading.local()
         self.local_error.translatable_error = None
 
+    def before(self, state):
+        self.local_error.translatable_error = None
+
     def after(self, state):
         if hasattr(state.response, 'translatable_error'):
             self.local_error.translatable_error = (

ceilometer/tests/api/v2/test_app.py

@@ -18,9 +18,11 @@
 # under the License.
 """Test basic ceilometer-api app
 """
+import json
 import os
 
 import mock
+import wsme
 
 from ceilometer.api import acl
 from ceilometer.api import app
@@ -207,3 +209,19 @@ class TestApiMiddleware(FunctionalTest):
         fault = response.xml.findall('./error/faultstring')
         for fault_string in fault:
             self.assertEqual(fault_string.text, self.en_US_translated_error)
+
+    def test_translated_then_untranslated_error(self):
+        resp = self.get_json('/alarms/alarm-id-3', expect_errors=True)
+        self.assertEqual(resp.status_code, 404)
+        self.assertEqual(json.loads(resp.body)['error_message']
+                         ['faultstring'], "Alarm alarm-id-3 Not Found")
+
+        with mock.patch('ceilometer.api.controllers.v2.EntityNotFound') \
+                as CustomErrorClass:
+            CustomErrorClass.return_value = wsme.exc.ClientSideError(
+                "untranslated_error", status_code=404)
+            resp = self.get_json('/alarms/alarm-id-5', expect_errors=True)
+
+        self.assertEqual(resp.status_code, 404)
+        self.assertEqual(json.loads(resp.body)['error_message']
+                         ['faultstring'], "untranslated_error")