sriov-device-mappings to allow regexps

[Alvaro Uria]

This bug is related to bug #1786283 (charm-nova-compute's pci-passthrough-whitelist) and bug #1736401 (don't add non-existing devices as data-port does).

We have nodes with network cards plugged in different slots, so SR-IOV interfaces can be named eno2 (on all nodes) but also enp131s0f1 or enp216s0f1 (depending on the slot they're plugged in).

Similar to the proposed fix for pci-passthrough-whitelist, I will send a patch proposal to support:
"""
neutron-openvswitch-vnf:
  sriov-device-mappings: 'physnet1:eno2 physnet2:enp(131|216)s0f1'
"""

Charm will check if the regexp matches a single interface (if more than one is matched, then hook would fail):
"""
$ cat /etc/neutron/plugins/ml2/sriov_agent.ini
[...]
[sriov_nic]
physical_device_mappings = physnet1:eno2,physnet2:enp216s0f1
"""

[Alvaro Uria (aluria)]

Change proposal at https://review.openstack.org/#/c/596694/

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Alvaro Uría <email address hidden>" on branch: master
Review: https://review.opendev.org/c/openstack/charm-neutron-openvswitch/+/596694
Reason: OpenStack charms now use OVN. This charm is not recommended on new environments.