l3-agent network_update() can throw an excetion if router ex_gw_port is None

[Brian Haley]

I've seen this error a couple of times in downstream testing, but looks like it could be just as broken upstream:

2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server [req-a1152197-d8b1-4e34-ae63-8a94fd69ebcd faf66db1b6de4c56a9925b9e5aa3369d c977198dffa24e6f8e9e8c8c4cf3211c - - -] Exception during message handling: TypeError: 'NoneType' object has no attribute '__getitem__'
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server Traceback (most recent call last):
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 160, in _process_incoming
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message)
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 213, in dispatch
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args)
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 183, in _do_dispatch
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args)
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/osprofiler/profiler.py", line 153, in wrapper
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server return f(*args, **kwargs)
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/osprofiler/profiler.py", line 153, in wrapper
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server return f(*args, **kwargs)
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/neutron/agent/l3/agent.py", line 446, in network_update
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server if any(port_belongs(p) for p in ports):
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/neutron/agent/l3/agent.py", line 446, in <genexpr>
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server if any(port_belongs(p) for p in ports):
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/neutron/agent/l3/agent.py", line 445, in <lambda>
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server port_belongs = lambda p: p['network_id'] == network_id
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server TypeError: 'NoneType' object has no attribute '__getitem__'
2017-10-09 18:36:29.507 126916 ERROR oslo_messaging.rpc.server

Since ri.ex_gw_port can be None, that can cause an exception when looking for ports we might have in that network. Here's an example if the port is None:

  ports = itertools.chain(ri.internal_ports, [ri.ex_gw_port])

>>> import itertools
>>> foo = itertools.chain([], [None])
>>> port_belongs = lambda p: p['network_id'] == network_id
>>> any(port_belongs(p) for p in foo)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <genexpr>
  File "<stdin>", line 1, in <lambda>
TypeError: 'NoneType' object has no attribute '__getitem__'

We need to check if it's None and use [] instead.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/512382

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/514578

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/512382
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=2cea213d94e3ac7675d62491cec6c85253285b92
Submitter: Zuul
Branch: master

commit 2cea213d94e3ac7675d62491cec6c85253285b92
Author: Brian Haley <email address hidden>
Date: Mon Oct 16 14:35:25 2017 -0400

    Do not try and iterate [None] in l3-agent network_update()

    Since ri.ex_gw_port can be None, the l3-agent can throw an
    exception when looking for ports it might have in a given
    network.

    Change-Id: I3ab3e9c012022cd7eefa5c609ca9540649079ad3
    Closes-bug: #1724043

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/514578
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=9414425ffa9210da846af841ac0493a48deddc0f
Submitter: Zuul
Branch: stable/pike

commit 9414425ffa9210da846af841ac0493a48deddc0f
Author: Brian Haley <email address hidden>
Date: Mon Oct 16 14:35:25 2017 -0400

    Do not try and iterate [None] in l3-agent network_update()

    Since ri.ex_gw_port can be None, the l3-agent can throw an
    exception when looking for ports it might have in a given
    network.

    (cherry picked from 2cea213d94e3ac7675d62491cec6c85253285b92)

    Change-Id: I3ab3e9c012022cd7eefa5c609ca9540649079ad3
    Closes-bug: #1724043

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 11.0.2 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 12.0.0.0b2 development milestone.