[OVN]Updating a QoS policy for a port will cause a KeyEerror

[zhanghao]

Reproduce this bug：
1.create a port with no qos policy.
2.update this port with a qos policy.

Since 'qos_options' does not have the 'direction' key, this bug is caused.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/707352

[Bence Romsics (bence-romsics)]

What are the exact commands to reproduce this bug?

As I read _create_qos_rules() I'm quite sure there is a problem here, but I can't seem to find how to reproduce it.

This succeeds for me:
openstack network qos policy create qp0
openstack network qos rule create --type bandwidth-limit --max-kbps 1000 qp0
openstack port create port0 --network private
openstack port set port0 --qos-policy qp0

And this too:
openstack network qos policy create qp0
openstack port create port0 --network private
openstack port set port0 --qos-policy qp0

On the other hand I found this to fail:
openstack network qos policy create qp0
openstack network qos rule create --type bandwidth-limit --max-kbps 1000 qp0
openstack port create port0 --network private --qos-policy qp0

But this one fails with KeyError: 'qos_burst':
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers [None req-4c0f75c2-b509-43db-af4b-49c072229a67 admin admin] Mechanism driver 'ovn' failed in create_port_postcommit: KeyError: 'qos_burst'
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers Traceback (most recent call last):
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers File "/opt/stack/neutron/neutron/plugins/ml2/managers.py", line 475, in _call_on_drivers
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers getattr(driver.obj, method_name)(context)
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers File "/opt/stack/neutron/neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py", line 530, in create_port_postcommit
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers self._ovn_client.create_port(port)
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers File "/opt/stack/neutron/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py", line 418, in create_port
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers port, lswitch_name)
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers File "/opt/stack/neutron/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py", line 718, in _create_qos_rules
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers burst=int(qos_options['qos_burst']),
febr 12 16:28:08 devstack0 neutron-server[8429]: ERROR neutron.plugins.ml2.managers KeyError: 'qos_burst'

Reading the relevant code...
https://opendev.org/openstack/neutron/src/commit/a026b39617f4c2d29f2903909fb65f7adb327fa7/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py#L701-L729
https://opendev.org/openstack/neutron/src/commit/a026b39617f4c2d29f2903909fb65f7adb327fa7/neutron/services/qos/drivers/ovn/driver.py#L117-L136
https://opendev.org/openstack/neutron/src/commit/a026b39617f4c2d29f2903909fb65f7adb327fa7/neutron/services/qos/drivers/ovn/driver.py#L97-L115
https://open...

[zhanghao (zhanghao2)]

Hi Bence, you need to specify both 'max-kbps' and 'max-burst-kbps' to see the KeyError caused by the direction. The problem you reported also exists.

[Akihiro Motoki (amotoki)]

zhanghao, why don't you provide the exact command line? Bence requested the exact command line, but you just tried to explain it. If you provide the exact command-line, the situation would be much simpler and Bence did not need to explore possible cases. Next time you file a bug, I would strongly suggest to provide the exact way to reproduce the bug (for example with command-line examples).

[Bence Romsics (bence-romsics)]

Hi zhanghao,

This one also succeeds for me:

openstack network qos policy create qp0
openstack network qos rule create --type bandwidth-limit --max-kbps 1000 --max-burst-kbits 800 qp0
openstack port create port0 --network private
openstack port set port0 --qos-policy qp0

I fully believe this bug exists, however I still don't know how to reproduce it from the command line.

[Bence Romsics (bence-romsics)]

For my previous comment about "OVO defaulted fields may not be present": I realized that we call .obj_set_defaults() in NeutronObject.__init__(), therefore the rule's OVO is going to always have the defaulted fields. Please ignore that part of comment #2.

[zhanghao (zhanghao2)]

Hi Bence, I I execute the same command lines as you.

The command lines do not prompt errors, check your neutron-server log，and if your network has a qos policy.

this is my neutron-server.log:
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers Traceback (most recent call last):
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/neutron/plugins/ml2/managers.py", line 426, in _call_on_drivers
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers getattr(driver.obj, method_name)(context)
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py", line 604, in update_port_postcommit
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers self._ovn_client.update_port(port, port_object=original_port)
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py", line 674, in update_port
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers if_delete=True)
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers File "/usr/lib/python2.7/site-packages/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_client.py", line 711, in _create_qos_rules
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers direction = 'from-lport' if qos_options['direction'] ==\
2020-02-19 22:00:18.490 32226 ERROR neutron.plugins.ml2.managers KeyError: 'direction'

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Rodolfo Alonso <email address hidden>" on branch: master
Review: https://review.opendev.org/c/openstack/neutron/+/707352
Reason: Superseded by https://review.opendev.org/c/openstack/neutron/+/711317