gnocchi: fix alarms for unpriviledged user

When an unprivileged user want to access to Gnocchi resources
created by Ceilometer, that doesn't work because the filter scope
the Gnocchi query to resource owner to the user. To fix we introduce
a new configuration option "gnocchi_external_project_owner" set by
default to "service". The new filter now allow two kind of Gnocchi
resources:
* owned by the user project
* owned by "gnocchi_external_project_owner" and the orignal project_id
  of the resource is the user project.

Change-Id: I0c86736a902a21520da18550aea0a7d1549bb24e

aodh/api/controllers/v2/alarm_rules/gnocchi.py

@@ -18,6 +18,8 @@ import threading
 import cachetools
 from gnocchiclient import client
 from gnocchiclient import exceptions
+from keystoneauth1 import exceptions as ka_exceptions
+from oslo_config import cfg
 from oslo_serialization import jsonutils
 import pecan
 import wsme
@@ -28,6 +30,14 @@ from aodh.api.controllers.v2 import utils as v2_utils
 from aodh import keystone_client
 
 
+GNOCCHI_OPTS = [
+    cfg.StrOpt('gnocchi_external_project_owner',
+               default="service",
+               help='Project name of resources creator in Gnocchi. '
+               '(For example the Ceilometer project name'),
+]
+
+
 class GnocchiUnavailable(Exception):
     code = 503
 
@@ -122,6 +132,20 @@ class AggregationMetricByResourcesLookupRule(AlarmGnocchiThresholdRule):
                                        'resource_type'])
         return rule
 
+    cache = cachetools.TTLCache(maxsize=1, ttl=3600)
+    lock = threading.RLock()
+
+    @staticmethod
+    @cachetools.cached(cache, lock=lock)
+    def get_external_project_owner():
+        kc = keystone_client.get_client(pecan.request.cfg)
+        project_name = pecan.request.cfg.api.gnocchi_external_project_owner
+        try:
+            project = kc.projects.find(name=project_name)
+            return project.id
+        except ka_exceptions.NotFound:
+            return None
+
     @classmethod
     def validate_alarm(cls, alarm):
         super(AggregationMetricByResourcesLookupRule,
@@ -135,14 +159,27 @@ class AggregationMetricByResourcesLookupRule(AlarmGnocchiThresholdRule):
         except ValueError:
             raise wsme.exc.InvalidInput('rule/query', rule.query)
 
+        conf = pecan.request.cfg
+
         # Scope the alarm to the project id if needed
         auth_project = v2_utils.get_auth_project(alarm.project_id)
         if auth_project:
-            query = {"and": [{"=": {"created_by_project_id": auth_project}},
-                             query]}
+
+            perms_filter = {"=": {"created_by_project_id": auth_project}}
+
+            external_project_owner = cls.get_external_project_owner()
+            if external_project_owner:
+                perms_filter = {"or": [
+                    perms_filter,
+                    {"and": [
+                        {"=": {"created_by_project_id":
+                               external_project_owner}},
+                        {"=": {"project_id": auth_project}}]}
+                ]}
+
+            query = {"and": [perms_filter, query]}
             rule.query = jsonutils.dumps(query)
 
-        conf = pecan.request.cfg
         gnocchi_client = client.Client(
             '1', keystone_client.get_session(conf),
             interface=conf.service_credentials.interface,

aodh/opts.py

@@ -16,6 +16,7 @@ import itertools
 from keystoneauth1 import loading
 
 import aodh.api
+import aodh.api.controllers.v2.alarm_rules.gnocchi
 import aodh.api.controllers.v2.alarms
 import aodh.coordination
 import aodh.evaluator
@@ -42,6 +43,7 @@ def list_opts():
         ('api',
          itertools.chain(
              aodh.api.OPTS,
+             aodh.api.controllers.v2.alarm_rules.gnocchi.GNOCCHI_OPTS,
              aodh.api.controllers.v2.alarms.ALARM_API_OPTS)),
         ('coordination', aodh.coordination.OPTS),
         ('database', aodh.storage.OPTS),

aodh/tests/functional/api/v2/test_alarm_scenarios.py

@@ -2607,7 +2607,9 @@ class TestAlarmsRuleGnocchi(TestAlarmsBase):
         self.assertEqual(1, len(alarms))
         self._verify_alarm(json, alarms[0])
 
-    def test_post_gnocchi_aggregation_alarm_project_constraint(self):
+    @mock.patch('aodh.keystone_client.get_client')
+    def test_post_gnocchi_aggregation_alarm_project_constraint(self,
+                                                               get_client):
         json = {
             'enabled': False,
             'name': 'project_constraint',
@@ -2630,10 +2632,21 @@ class TestAlarmsRuleGnocchi(TestAlarmsBase):
             }
         }
 
-        expected_query = {"and": [{"=": {"created_by_project_id":
-                                         self.auth_headers['X-Project-Id']}},
-                                  {"=": {"server_group":
-                                         "my_autoscaling_group"}}]}
+        expected_query = {"and": [
+            {"or": [
+                {"=": {"created_by_project_id":
+                       self.auth_headers['X-Project-Id']}},
+                {"and": [
+                    {"=": {"created_by_project_id": "<my-uuid>"}},
+                    {"=": {"project_id": self.auth_headers['X-Project-Id']}}
+                ]},
+            ]},
+            {"=": {"server_group": "my_autoscaling_group"}},
+        ]}
+
+        ks_client = mock.Mock()
+        ks_client.projects.find.return_value = mock.Mock(id='<my-uuid>')
+        get_client.return_value = ks_client
 
         with mock.patch('aodh.api.controllers.v2.alarm_rules.'
                         'gnocchi.client') as clientlib:

releasenotes/notes/gnocchi-external-resource-owner-3fad253d30746b0d.yaml

@@ -0,0 +1,11 @@
+---
+fixes:
+  - |
+    When an unprivileged user want to access to Gnocchi resources created by
+    Ceilometer, that doesn't work because the filter scope the Gnocchi query to
+    resource owner to the user. To fix we introduce a new configuration option
+    "gnocchi_external_project_owner" set by default to "service". The new
+    filter now allow two kind of Gnocchi resources:
+    * owned by the user project
+    * owned by "gnocchi_external_project_owner" and the orignal project_id of
+      the resource is the user project.