From: Fei Long Wang <flwang@catalyst.net.nz>
Date: Mon, 16 Feb 2015 11:58:45 +0000 (+1300)
Subject: Fix metering agent failure when chain missing
X-Git-Url: https://review.fuel-infra.org/gitweb?a=commitdiff_plain;h=c3b7f1b2ae7af995f4815e3571c9828683dc0db7;p=openstack-build%2Fneutron-build.git

Fix metering agent failure when chain missing

The metering agent will fail if one of the iptables chains
is missing, which will cause errors extracting data from
all the other chains. Add a simple try/except to let the
loop continue.

Closes-Bug: #1421037

Change-Id: I370ee0e2cc58ca7e1c5ef9bf4dbcce5abf7545a1
---

diff --git a/neutron/services/metering/drivers/iptables/iptables_driver.py b/neutron/services/metering/drivers/iptables/iptables_driver.py
index 8bdec808c..0e828f096 100644
--- a/neutron/services/metering/drivers/iptables/iptables_driver.py
+++ b/neutron/services/metering/drivers/iptables/iptables_driver.py
@@ -23,7 +23,7 @@ from neutron.agent.linux import iptables_manager
 from neutron.common import constants as constants
 from neutron.common import ipv6_utils
 from neutron.common import log
-from neutron.i18n import _LI
+from neutron.i18n import _LE, _LI
 from neutron.services.metering.drivers import abstract_driver
 
 
@@ -266,11 +266,18 @@ class IptablesMeteringDriver(abstract_driver.MeteringAbstractDriver):
                 continue
 
             for label_id, label in rm.metering_labels.items():
-                chain = iptables_manager.get_chain_name(WRAP_NAME + LABEL +
-                                                        label_id, wrap=False)
+                try:
+                    chain = iptables_manager.get_chain_name(WRAP_NAME +
+                                                            LABEL +
+                                                            label_id,
+                                                            wrap=False)
 
-                chain_acc = rm.iptables_manager.get_traffic_counters(
-                    chain, wrap=False, zero=True)
+                    chain_acc = rm.iptables_manager.get_traffic_counters(
+                        chain, wrap=False, zero=True)
+                except RuntimeError:
+                    LOG.exception(_LE('Failed to get traffic counters, '
+                                      'router: %s'), router)
+                    continue
 
                 if not chain_acc:
                     continue
diff --git a/neutron/tests/unit/services/metering/drivers/test_iptables_driver.py b/neutron/tests/unit/services/metering/drivers/test_iptables_driver.py
index 292a79839..45dd32027 100644
--- a/neutron/tests/unit/services/metering/drivers/test_iptables_driver.py
+++ b/neutron/tests/unit/services/metering/drivers/test_iptables_driver.py
@@ -360,3 +360,19 @@ class IptablesDriverTestCase(base.BaseTestCase):
                                         wrap=False)]
 
         self.v4filter_inst.assert_has_calls(calls)
+
+    def test_get_traffic_counters_with_missing_chain(self):
+        for r in TEST_ROUTERS:
+            rm = iptables_driver.RouterWithMetering(self.metering.conf, r)
+            rm.metering_labels = {r['_metering_labels'][0]['id']: 'fake'}
+            self.metering.routers[r['id']] = rm
+
+        mocked_method = self.iptables_cls.return_value.get_traffic_counters
+        mocked_method.side_effect = [{'pkts': 1, 'bytes': 8},
+                                     RuntimeError('Failed to find the chain')]
+
+        counters = self.metering.get_traffic_counters(None, TEST_ROUTERS)
+        expected_label_id = TEST_ROUTERS[0]['_metering_labels'][0]['id']
+        self.assertIn(expected_label_id, counters)
+        self.assertEqual(1, counters[expected_label_id]['pkts'])
+        self.assertEqual(8, counters[expected_label_id]['bytes'])