fix: validate queue listing limits in proxy

Adds the appropriate unit test to show that this works and keeps
working for the forseeable future.

Change-Id: I25d3ba3f9b1e3a51d8ba86171cd7329585c3e080
Closes-Bug: 1234481

marconi/proxy/storage/__init__.py

@@ -3,7 +3,6 @@
 from marconi.proxy.storage import base
 from marconi.proxy.storage import exceptions  # NOQA
 
-
 # NOTE(cpp-cabrera): Hoist classes into package namespace
 CatalogueBase = base.CatalogueBase
 DriverBase = base.DriverBase

marconi/proxy/transport/wsgi/queues.py

@@ -31,13 +31,20 @@
 import json
 
 import falcon
+from oslo.config import cfg
+import six
 
 from marconi.openstack.common import log
 from marconi.proxy.utils import (
     forward, lookup, helpers, http, partition
 )
+from marconi.queues import storage  # NOQA
+from marconi.queues.transport import validation as validate
+from marconi.queues.transport.wsgi import exceptions as wsgi_exceptions
+
 
 LOG = log.getLogger(__name__)
+STORAGE_LIMITS = cfg.CONF['queues:limits:storage']
 
 
 class Listing(object):
@@ -62,6 +69,14 @@ def on_get(self, request, response):
         request.get_param_as_bool('detailed', store=kwargs)
 
         resp = collections.defaultdict(list)
+        limit = kwargs.get('limit',
+                           STORAGE_LIMITS.default_queue_paging)
+
+        try:
+            validate.queue_listing(limit=limit)
+        except validate.ValidationFailed as ex:
+            raise wsgi_exceptions.HTTPBadRequestAPI(six.text_type(ex))
+
         for queue in self._catalogue.list(project):
             queue_name = queue['name']
             if queue_name < kwargs.get('marker', ''):
@@ -74,7 +89,7 @@ def on_get(self, request, response):
                 entry['metadata'] = queue['metadata']
             resp['queues'].append(entry)
             kwargs['marker'] = queue_name
-            if len(resp['queues']) == kwargs.get('limit', 0):
+            if len(resp['queues']) == limit:
                 break
 
         if not resp:

tests/unit/proxy/test_queues.py

@@ -132,6 +132,12 @@ def test_list_queues_with_option_detailed(self):
         for entry in doc['queues']:
             self.assertIn('metadata', entry)
 
+    @ddt.data(-1, 0, 30)
+    def test_list_queues_raises_400_with_invalid_limit(self, limit):
+        self.simulate_get('/v1/queues',
+                          query_string='limit={0}'.format(limit))
+        self.assertEqual(self.srmock.status, falcon.HTTP_400)
+
 
 @ddt.ddt
 class QueuesWithNoPartitionsTest(base.TestBase):