api: return 404 if a resource is not found

This also checks for the error message that is returned, and fixes a
problem with the error encoding middleware that was doing double JSON
encoding.

Change-Id: Ieb39a991ddc9ecba0a7e71450a1e57ede18ccbe6
Fixes-Bug: #1218760
Fixes-Bug: #1208552

ceilometer/api/controllers/v2.py

@@ -2,10 +2,12 @@
 #
 # Copyright © 2012 New Dream Network, LLC (DreamHost)
 # Copyright 2013 IBM Corp.
+# Copyright © 2013 eNovance <licensing@enovance.com>
 #
-# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
-#         Angus Salkeld <asalkeld@redhat.com>
-#         Eoghan Glynn <eglynn@redhat.com>
+# Authors: Doug Hellmann <doug.hellmann@dreamhost.com>
+#          Angus Salkeld <asalkeld@redhat.com>
+#          Eoghan Glynn <eglynn@redhat.com>
+#          Julien Danjou <julien@danjou.info>
 #
 # 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
@@ -864,6 +866,14 @@ def sample(cls):
                    )
 
 
+class ResourceNotFound(Exception):
+    code = 404
+
+    def __init__(self, id):
+        super(ResourceNotFound, self).__init__(
+            _("Resource %s Not Found") % id)
+
+
 class ResourcesController(rest.RestController):
     """Works on resources."""
 
@@ -886,14 +896,8 @@ def get_one(self, resource_id):
         authorized_project = acl.get_limited_to_project(pecan.request.headers)
         resources = list(pecan.request.storage_conn.get_resources(
             resource=resource_id, project=authorized_project))
-        # FIXME (flwang): Need to change this to return a 404 error code when
-        # we get a release of WSME that supports it.
         if not resources:
-            error = _("Unknown resource")
-            pecan.response.translatable_error = error
-            raise wsme.exc.InvalidInput("resource_id",
-                                        resource_id,
-                                        unicode(error))
+            raise ResourceNotFound(resource_id)
         return Resource.from_db_and_links(resources[0],
                                           self._resource_links(resource_id))
 

ceilometer/api/middleware.py

@@ -125,7 +125,7 @@ def replacement_start_response(status, headers, exc_info=None):
                         fault['faultstring'] = (
                             gettextutils.get_localized_message(
                                 error, user_locale))
-                    body = [json.dumps({'error_message': json.dumps(fault)})]
+                    body = [json.dumps({'error_message': fault})]
                 except ValueError as err:
                     body = [json.dumps({'error_message': '\n'.join(app_iter)})]
                 state['headers'].append(('Content-Type', 'application/json'))

tests/api/v2/test_alarm_scenarios.py

@@ -243,9 +243,8 @@ def test_post_alarm_wsme_workaround(self):
             resp = self.post_json('/alarms', params=json, expect_errors=True,
                                   status=400, headers=self.auth_headers)
             self.assertEqual(
-                resp.json['error_message'],
-                '{"debuginfo": null, "faultcode": "Client", "faultstring": '
-                '"%s is mandatory"}' % field)
+                resp.json['error_message']['faultstring'],
+                '%s is mandatory' % field)
         alarms = list(self.conn.get_alarms())
         self.assertEqual(4, len(alarms))
 
@@ -323,10 +322,9 @@ def test_post_invalid_alarm_have_multiple_rules(self):
         alarms = list(self.conn.get_alarms())
         self.assertEqual(4, len(alarms))
         self.assertEqual(
-            resp.json['error_message'],
-            '{"debuginfo": null, "faultcode": "Client", "faultstring": '
-            '"threshold_rule and combination_rule cannot '
-            'be set at the same time"}')
+            resp.json['error_message']['faultstring'],
+            'threshold_rule and combination_rule cannot '
+            'be set at the same time')
 
     def test_post_alarm_defaults(self):
         to_check = {

tests/api/v2/test_app.py

@@ -18,7 +18,6 @@
 # under the License.
 """Test basic ceilometer-api app
 """
-import json
 import os
 
 from oslo.config import cfg
@@ -141,8 +140,8 @@ def test_json_parsable_error_middleware_translation_400(self):
         self.assertEqual(response.status_int, 400)
         self.assertEqual(response.content_type, "application/json")
         self.assertTrue(response.json['error_message'])
-        fault = json.loads(response.json['error_message'])
-        self.assertEqual(fault['faultstring'], self.no_lang_translated_error)
+        self.assertEqual(response.json['error_message']['faultstring'],
+                         self.no_lang_translated_error)
 
     def test_xml_parsable_error_middleware_404(self):
         response = self.get_json('/invalid_path',

tests/api/v2/test_list_resources_scenarios.py

@@ -19,6 +19,7 @@
 """
 
 import datetime
+import json
 import logging
 import testscenarios
 
@@ -249,7 +250,10 @@ def test_with_invalid_resource_id(self):
         self.assertEqual(resp2["resource_id"], "resource-id-2")
 
         resp3 = self.get_json('/resources/resource-id-3', expect_errors=True)
-        self.assertEqual(resp3.status_code, 400)
+        self.assertEqual(resp3.status_code, 404)
+        self.assertEqual(json.loads(resp3.body)['error_message']
+                         ['faultstring'],
+                         "Resource resource-id-3 Not Found")
 
     def test_with_user(self):
         sample1 = sample.Sample(