Comment 2 for bug 1748389

I think this was not the case for neutron lbaasv2 api, atleast with the CLI what I can see.

stack@ubuntu-devstack:~/devstack$ neutron lbaas-listener-create --protocol HTTP --protocol-port 8000
neutron CLI is deprecated and will be removed in the future. Use openstack CLI instead.
Either --default-pool or --loadbalancer must be specified.

AFAIK, the concept of shared pool is that there is a N:M relationship between listeners and pools. So when you specify a loadbalancer (rather than a listener) for a pool, then the pool is expected to be shared between listeners and they use either the l7policy to identify the pool to use or use the default pool.

We changed that in the lbaasv2 resource in https://review.openstack.org/#/c/419385/3/heat/engine/resources/openstack/neutron/lbaas/listener.py.

It would be worth checking with octavia team about this. The API ref though says that it's required, which is confusing.