Fix l3-agent crash on routers without ha_state

l3-agent checks the HA state of routers when a router is updated.
To ensure that the HA state is only checked on HA routers the following
check is performed: `if router.get('ha') and not is_dvr_only_agent`.
This check should ensure that the check is only performed on
DvrEdgeHaRouter and HaRouter objects.

Unfortunately, there are cases where we have DvrEdgeRouter objects
running on 'dvr_snat' agents. E.g. when deploying a loadbalancer with
neutron-lbaas in a landscape with 6 network nodes and
max_l3_agents_per_router set to 3, it may happen that the loadbalancer
is placed on a network node that does not have a DvrEdgeHaRouter running
on it. In such a case, neutron will deploy a DvrEdgeRouter object on the
network node to serve the loadbalancer, just like it would deploy a
DvrEdgeRouter on a compute node when deploying a VM.

Under such circumstances each update to the router will lead to an
AttributeError, because the DvrEdgeRouter object does not have the
ha_state attribute.

This patch circumvents the issue by doing an additional check on the
router object to ensure that it actually has the ha_state attribute.

Change-Id: I755990324db445efd0ee0b8a9db1f4d7bfb58e26
Closes-Bug: #1755243
This commit is contained in:
Daniel Gonzalez 2018-03-12 17:48:54 +01:00
parent 3da1630001
commit 8c2dae659a
3 changed files with 35 additions and 9 deletions

View File

@ -489,14 +489,15 @@ class L3NATAgent(ha.AgentMixin,
self.l3_ext_manager.add_router(self.context, router)
def _process_updated_router(self, router):
ri = self.router_info[router['id']]
is_dvr_only_agent = (self.conf.agent_mode in
[lib_const.L3_AGENT_MODE_DVR,
lib_const.L3_AGENT_MODE_DVR_NO_EXTERNAL])
is_ha_router = getattr(ri, 'ha_state', None) is not None
# For HA routers check that DB state matches actual state
if router.get('ha') and not is_dvr_only_agent:
if router.get('ha') and not is_dvr_only_agent and is_ha_router:
self.check_ha_state_for_router(
router['id'], router.get(l3_constants.HA_ROUTER_STATE_KEY))
ri = self.router_info[router['id']]
ri.router = router
registry.notify(resources.ROUTER, events.BEFORE_UPDATE,
self, router=ri)

View File

@ -1125,11 +1125,11 @@ class TestDvrRouter(framework.L3AgentTestFramework):
self.assertFalse(sg_device)
self.assertTrue(qg_device)
def _mocked_dvr_ha_router(self, agent, enable_gw=True,
def _mocked_dvr_ha_router(self, agent, enable_ha=True, enable_gw=True,
enable_centralized_fip=False,
snat_bound_fip=False):
r_info = self.generate_dvr_router_info(
enable_ha=True,
enable_ha=enable_ha,
enable_snat=True,
agent=agent,
enable_gw=enable_gw,
@ -1165,7 +1165,7 @@ class TestDvrRouter(framework.L3AgentTestFramework):
def _create_dvr_ha_router(self, agent, enable_gw=True,
enable_centralized_fip=False,
snat_bound_fip=False):
snat_bound_fip=False, ha_interface=True):
get_ns_name = mock.patch.object(namespaces.RouterNamespace,
'_get_ns_name').start()
get_snat_ns_name = mock.patch.object(dvr_snat_ns.SnatNamespace,
@ -1173,7 +1173,11 @@ class TestDvrRouter(framework.L3AgentTestFramework):
(r_info,
mocked_r_ns_name,
mocked_r_snat_ns_name) = self._mocked_dvr_ha_router(
agent, enable_gw, enable_centralized_fip, snat_bound_fip)
agent, ha_interface, enable_gw, enable_centralized_fip,
snat_bound_fip)
if not ha_interface:
r_info['ha'] = True
get_ns_name.return_value = mocked_r_ns_name
get_snat_ns_name.return_value = mocked_r_snat_ns_name
@ -1331,6 +1335,26 @@ class TestDvrRouter(framework.L3AgentTestFramework):
def test_dvr_ha_router_failover_without_gw(self):
self._test_dvr_ha_router_failover(enable_gw=False)
def test_dvr_non_ha_router_update(self):
self._setup_dvr_ha_agents()
self._setup_dvr_ha_bridges()
router1 = self._create_dvr_ha_router(self.agent)
router2 = self._create_dvr_ha_router(self.failover_agent,
ha_interface=False)
r1_chsfr = mock.patch.object(self.agent,
'check_ha_state_for_router').start()
r2_chsfr = mock.patch.object(self.failover_agent,
'check_ha_state_for_router').start()
utils.wait_until_true(lambda: router1.ha_state == 'master')
self.agent._process_updated_router(router1.router)
self.assertTrue(r1_chsfr.called)
self.failover_agent._process_updated_router(router2.router)
self.assertFalse(r2_chsfr.called)
def _setup_dvr_router_static_routes(
self, router_namespace=True, check_fpr_int_rule_delete=False):
"""Test to validate the extra routes on dvr routers."""

View File

@ -2532,9 +2532,10 @@ class TestBasicRouterOperations(BasicRouterOperationsFramework):
'distributed': True, 'ha': True,
'external_gateway_info': {}, 'routes': [],
'admin_state_up': True}
agent._process_router_if_compatible(router)
self.assertIn(router['id'], agent.router_info)
with mock.patch.object(agent, 'check_ha_state_for_router') as chsfr:
agent._process_router_if_compatible(router)
self.assertIn(router['id'], agent.router_info)
self.assertFalse(chsfr.called)
def test_process_router_if_compatible_with_no_ext_net_in_conf(self):
self.conf.set_override('external_network_bridge', 'br-ex')