dynamic-routing: address_scope calculation error

[Roberto Acosta]

Neutron dynamic routing needs to be fixed in the iteration to obtain address_scope linked to a provider network with multiple subnets. A network can be linked to more than one subnet (e.g. ipv4 and ipv6), but if one of them does not have an address_scope, a null object element access failure occurs.

Fix proposed in the neutron-dynamic-routing project [1].

[1] - https://review.opendev.org/c/openstack/neutron-dynamic-routing/+/863708

Steps to reproduce:

#1 - IPv6 address scope
openstack address scope create --share --ip-version 6 bgp

#2 - self-service subnet pool
openstack subnet pool create --address-scope address-scope-ipv6 --share --default --pool-prefix 2001:db9:1234::/48 --default-prefix-length 64 --max-prefix-length 64 default-pool-ipv6

#3 - provider subnet pool
openstack subnet pool create --address-scope address-scope-ipv6 --pool-prefix 2001:db9:4321:42::/64 --default-prefix-length 64 public-pool-ipv6

#4 - Provider network
openstack network create provider --external --provider-physical-network \
  provider --provider-network-type flat
#5 - provider subnet
openstack subnet create --ip-version 6 --subnet-pool public-pool-ipv6 --network provider --ipv6-address-mode dhcpv6-stateful --ipv6-ra-mode dhcpv6-stateful provider1-v6
openstack subnet create --ip-version 4 --network provider --dhcp --host-route destination=200.201.0.0/24,gateway=200.201.0.1 --subnet-range 200.201.0.0/24 provider1-v4

#6 - self-service network
openstack network create self-service

#7 - self-service subnet
openstack subnet create --ip-version 6 --subnet-pool default-pool-ipv6 --network self-service --ipv6-address-mode dhcpv6-stateful --ipv6-ra-mode dhcpv6-stateful self-service-v6
openstack subnet create --ip-version 4 --network self-service --dhcp --host-route destination=192.168.0.0/24,gateway=192.168.0.1 --subnet-range 192.168.0.0/24 self-service-v4

#8 - create router
openstack router create router1

#9 - add self-service subnet as an interface on the router
openstack router add subnet router1 self-service-v4
openstack router add subnet router1 self-service-v6

#10 - Add the provider network as a gateway on each router.
openstack router set --external-gateway provider router1

#11 - create bgp speaker
openstack bgp speaker create --ip-version 6 --local-as 65000 bgpspeaker
openstack bgp speaker add network bgpspeaker provider

#12 - create a vm on the self-service network
openstack server create --image cirros --flavor 1vcpu --network=self-service --security-group cf2e7d53-0db7-4873-82ab-cf67eceda937 vm1

# We can see the messages below in the neutron log:

Nov 07 14:20:00 os-infra-1-neutron-server-container-819795c0 neutron-server[3698]: 2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager [req-24fe543c-7122-4869-b52d-21ecb782ea0e 8c140d00a7754295beae4ac85c5beecc 115a2ce896ad4958a26e3a4d624902a5 - default default] Error during notification for neutron_dynamic_routing.services.bgp.bgp_plugin.BgpPlugin.port_callback-950729 port, after_update: AttributeError: 'NoneType' object has no attribute 'address_scope_id'
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager Traceback (most recent call last):
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager File "/usr/lib/python3/dist-packages/neutron_lib/callbacks/manager.py", line 181, in _notify_loop
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager callback(resource, event, trigger, payload=payload)
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager File "/usr/lib/python3/dist-packages/neutron_dynamic_routing/services/bgp/bgp_plugin.py", line 375, in port_callback
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager ext_nets = self.get_external_networks_for_port(ctx,
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager File "/usr/lib/python3/dist-packages/neutron_dynamic_routing/db/bgp_db.py", line 1190, in get_external_networks_for_port
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager ext_scope_set.add(ext_pool.address_scope_id)
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager AttributeError: 'NoneType' object has no attribute 'address_scope_id'
                                                                                   2022-11-07 14:20:00.472 3698 ERROR neutron_lib.callbacks.manager

[Brian Haley (brian-haley)]

Since the closes-bug in the commit message was added late, adding a link to the patch.

https://review.opendev.org/c/openstack/neutron-dynamic-routing/+/863708

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/neutron-dynamic-routing/+/863708
Committed: https://opendev.org/openstack/neutron-dynamic-routing/commit/feff164b608d00bf8163ea259305c3a64e68c1da
Submitter: "Zuul (22348)"
Branch: master

commit feff164b608d00bf8163ea259305c3a64e68c1da
Author: ROBERTO BARTZEN ACOSTA <email address hidden>
Date: Fri Nov 4 17:01:08 2022 -0300

    Fix address_scope calculation

    Fix in the iteration to obtain address_scope linked to a subnet.
    A network can be linked to more than one subnet (ipv4 and ipv6),
    but if one of them does not have an address_scope, a null object
    element access failure occurs.

    Closes-bug: #1998104
    Change-Id: Ic6d48a86043aaf4b458bb2230883a355fc841ee9

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron-dynamic-routing 22.0.0.0rc1 release candidate.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/zed
Review: https://review.opendev.org/c/openstack/neutron-dynamic-routing/+/883583

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/openstack/neutron-dynamic-routing/+/883583
Committed: https://opendev.org/openstack/neutron-dynamic-routing/commit/962bb66743caf8b9052776a32ab71c83403dcd54
Submitter: "Zuul (22348)"
Branch: stable/zed

commit 962bb66743caf8b9052776a32ab71c83403dcd54
Author: ROBERTO BARTZEN ACOSTA <email address hidden>
Date: Fri Nov 4 17:01:08 2022 -0300

    Fix address_scope calculation

    Fix in the iteration to obtain address_scope linked to a subnet.
    A network can be linked to more than one subnet (ipv4 and ipv6),
    but if one of them does not have an address_scope, a null object
    element access failure occurs.

    Closes-bug: #1998104
    Change-Id: Ic6d48a86043aaf4b458bb2230883a355fc841ee9
    (cherry picked from commit feff164b608d00bf8163ea259305c3a64e68c1da)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron-dynamic-routing 21.0.1 release.