Comment 0 for bug 1944666

Corresponding upstream story link: https://storyboard.openstack.org/#!/story/2009117

Created a loadbalancer and a listener with protocol tcp protocol_port 1025 and allowed_cidr 0.0.0.0/0, the listener ends up in provisioning status as ERROR.

Error message in Octavia worker log
neutronclient.common.exceptions.Conflict: Security group rule already exists

This is a very edge case only when protocol port is 1025 (same as peer port which is hardcoded to constants.HAPROXY_BASE_PEER_PORT i.e, 1025) and allowed_cidr is explicitly set to 0.0.0.0/0.

Reproducer:
openstack loadbalancer create --name lb1 --vip-subnet-id private_subnet
openstack loadbalancer listener create --name lb1-listener --protocol tcp --protocol-port 1025 --allowed-cidr 0.0.0.0/0 lb1
openstack loadbalancer listener show lb1-listener lb1

The culprit is [1] where the allowed_cidr for peer port should handle both None and 0.0.0.0/0 as 0.0.0.0/0 is the default value.

Tested on: Ubuntu Focal Ussuri Octavia packages

Fix available in Upstream until stable/train (not part of any point release)
https://review.opendev.org/c/openstack/octavia/+/804485

[1] https://opendev.org/openstack/octavia/src/commit/b89c929c12fb262f59ba320a37f2a5bf4109df98/octavia/network/drivers/neutron/allowed_address_pairs.py#L150-L178