Incorrect floating IP association management on different private networks with same CIDR

[Diko Parvanov]

Environment:

xenial/queens

Horizon packages:

ii openstack-dashboard 3:13.0.1-0ubuntu4~cloud0 all Django web interface for OpenStack
ii openstack-dashboard-ubuntu-theme 3:13.0.1-0ubuntu4~cloud0 all Transitional dummy package for Ubuntu theme for Horizon
ii python-designate-dashboard 6.0.0-0ubuntu1.1~cloud0 all OpenStack DNS as a Service - dashboard plugin
ii python-heat-dashboard 1.0.2-0ubuntu2.1~cloud0 all OpenStack orchestration service - dashboard plugin
ii python-neutron-lbaas-dashboard 4.0.0-0ubuntu1~cloud0 all Loadbalancer-as-a-Service driver for OpenStack Neutron
ii python-django-horizon 3:13.0.1-0ubuntu4~cloud0 all Django module providing web based interaction with OpenStack

Neutron packages:
ii neutron-common 2:12.0.5-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - common
ii neutron-plugin-ml2 2:12.0.5-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - ML2 plugin
ii neutron-server 2:12.0.5-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - server
ii python-neutron 2:12.0.5-0ubuntu1~cloud0 all Neutron is a virtual network service for Openstack - Python library
ii python-neutron-dynamic-routing 2:12.0.0-0ubuntu1.1~cloud0 all OpenStack Neutron Dynamic Routing - Python 2.7 library
ii python-neutron-fwaas 1:12.0.1-0ubuntu1~cloud0 all Firewall-as-a-Service driver for OpenStack Neutron
ii python-neutron-lbaas 2:12.0.0-0ubuntu1~cloud0 all Loadbalancer-as-a-Service driver for OpenStack Neutron
ii python-neutron-lib 1.13.0-0ubuntu1~cloud0 all Neutron shared routines and utilities - Python 2.7
ii python-neutronclient 1:6.7.0-0ubuntu1~cloud0 all client API library for Neutron - Python 2.7

- 2 different projects with 2 different networks with subnets with the same CIDR
- 2 Floating IPs (FIP1 and FIP2)
- FIP1 assigned to instance in NET1/IP (same private IP address for both FIPs)
- FIP2 assigned to LBAAS load balancer in NET2/IP (same private IP address for both FIPs)

When doing a disassociate FIP2 on lbaas load balancer (horizon AND cli same result) - the horizon showed FIP1 as assigned to loadbalancer, even thou FIP1 still works assigned to the other VM.

Doing the disassociate again results in FIP1 removed from the instance.

I am guessing neutron does not filter the results by (fixed_ip_address & subnet_id), but only looking up by fixed_ip_address.

[Diko Parvanov (dparv)]

Also same issue reported here: https://bugs.launchpad.net/charm-openstack-dashboard/+bug/1866140