trailing slash in url causes 404 error

when accessing samples for a specific meter, appending a trailing
slash will add an empty target path to 'remainder', in turn
triggering 404 error. in case last target path in remainder, we
will drop that empty instance.

Change-Id: I583a0fe9755c9bec8bcb08b13a3f1d03a3acf336
Fixes:Bug#1202739

ceilometer/api/controllers/v2.py

@@ -618,6 +618,9 @@ class MetersController(rest.RestController):
 
     @pecan.expose()
     def _lookup(self, meter_id, *remainder):
+        # NOTE(gordc): drop last path if empty (Bug #1202739)
+        if remainder and not remainder[-1]:
+            remainder = remainder[:-1]
         return MeterController(meter_id), remainder
 
     @wsme_pecan.wsexpose([Meter], [Query])

tests/api/v2/list_events.py

@@ -82,6 +82,10 @@ class TestListEvents(FunctionalTest):
         data = self.get_json('/meters/instance')
         self.assertEquals(2, len(data))
 
+    def test_all_trailing_slash(self):
+        data = self.get_json('/meters/instance/')
+        self.assertEquals(2, len(data))
+
     def test_all_limit(self):
         data = self.get_json('/meters/instance?limit=1')
         self.assertEquals(1, len(data))