If qos service_plugin is enabled, but ml2 extension driver is not, api requests attaching policies to ports or nets will fail with an ugly exception

[Miguel Angel Ajo]

$ neutron port-update b0885ae1-487b-40bc-8fc0-32432a21e39d --qos-policy bw-limiter
Request Failed: internal server error while processing your request.

Neutron Exception:

DEBUG neutron.api.v2.base [req-218cddfd-2b7d-4050-91db-251c139029b2 admin 85b859134de2428d94f6ee910dc545d8] Request body: {u'port': {u'qos_policy_id': u'0ee1c673-5671-40ca-b55f-4cd4bbd999c7'}} from (pid=18237) prepare_request_body /opt/stack/neutron/neutron/api/v2/base.py:645
2015-09-15 01:05:26.022 ERROR neutron.api.v2.resource [req-218cddfd-2b7d-4050-91db-251c139029b2 admin 85b859134de2428d94f6ee910dc545d8] update failed
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource Traceback (most recent call last):
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/api/v2/resource.py", line 83, in resource
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource result = method(request=request, **args)
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource File "/usr/local/lib/python2.7/dist-packages/oslo_db/api.py", line 146, in wrapper
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource ectxt.value = e.inner_exc
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 195, in __exit__
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource six.reraise(self.type_, self.value, self.tb)
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource File "/usr/local/lib/python2.7/dist-packages/oslo_db/api.py", line 136, in wrapper
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource return f(*args, **kwargs)
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/api/v2/base.py", line 613, in update
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource obj = obj_updater(request.context, id, **kwargs)
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource File "/opt/stack/neutron/neutron/plugins/ml2/plugin.py", line 1158, in update_port
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource original_port[qos_consts.QOS_POLICY_ID] !=
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource KeyError: 'qos_policy_id'
2015-09-15 01:05:26.022 TRACE neutron.api.v2.resource
2015-09-15 01:05:26.026 INFO neutron.wsgi [req-218cddfd-2b7d-4050-91db-251c139029b2 admin 85b859134de2428d94f6ee910dc545d8] 172.16.175.128 - - [15/Sep/2015 01:05:26] "PUT /v2.0/ports/b0885ae1-487b-40bc-8fc0-32432a21e39d.json HTTP/1.1" 500 383 0.084317

[Miguel Angel Ajo (mangelajo)]

bug report details received from Edgar Magana, confirmed by me.

[Miguel Angel Ajo (mangelajo)]

We need to provide a better exception, this issue will go away when we have core resource extensions in core neutron (not only ml2)

[Assaf Muller (amuller)]

Is it possible for QoS service plugin to check if the ML2 extension is enabled, and if not, print an error and shut down the server?

[Miguel Angel Ajo (mangelajo)]

@assaf, that makes sense as a short-term solution, I'd remove it in the future when we have core resource extension in
neutron core: the service would declare itself the provider of the such extension (otherwise without the service plugin installed it doesn't make sense).

If that wasn't the case I'd say: we're coupling qos too much into Ml2, but that's what we have now, so we can check

1) if ml2 is the installed plugin:
    b) check if qos extension driver is enabled.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/253853

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/253853
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=c615c6f3a7a05dac8684366dde78080f347964dd
Submitter: Jenkins
Branch: master

commit c615c6f3a7a05dac8684366dde78080f347964dd
Author: Sławek Kapłoński <email address hidden>
Date: Sun Dec 6 00:11:46 2015 +0100

    ML2: verify if required extension drivers are loaded

    This change ensures extension drivers required by service plugins are loaded
    when using ML2 plugin: we check that ML2 loads QoS extension driver when QoS
    service plugin is enabled.

    Change-Id: Ibf19e77b88ce34c58519ae157c852c9e2b30e31f
    Closes-bug: #1496787