Hey

I noticed that port created during this test having IPv6 HAS NO dhcpv6 options set:

stack@mjozefcz-tempest-plugin-failed-install:~/neutron/neutron$ openstack subnet show 307d0cc8-481f-4052-b933-e4eaa84c1e53
+----------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| Field                | Value                                                                                                                                            |
+----------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| allocation_pools     | 2001:db8::2-2001:db8::ffff:ffff:ffff:ffff                                                                                                        |
| cidr                 | 2001:db8::/64                                                                                                                                    |
| created_at           | 2020-06-08T13:45:55Z                                                                                                                             |
| description          |                                                                                                                                                  |
| dns_nameservers      |                                                                                                                                                  |
| dns_publish_fixed_ip | False                                                                                                                                            |
| enable_dhcp          | True                                                                                                                                             |
| gateway_ip           | 2001:db8::1                                                                                                                                      |
| host_routes          |                                                                                                                                                  |
| id                   | 307d0cc8-481f-4052-b933-e4eaa84c1e53                                                                                                             |
| ip_version           | 6                                                                                                                                                |
| ipv6_address_mode    | slaac                                                                                                                                            |
| ipv6_ra_mode         | slaac                                                                                                                                            |
| location             | cloud='', project.domain_id=, project.domain_name=, project.id='97ab32e6e26143f9938405a6e36180f7', project.name=, region_name='RegionOne', zone= |
| name                 |                                                                                                                                                  |
| network_id           | d2dcc8be-de00-4010-b7f6-5e462294a0f1                                                                                                             |
| prefix_length        | None                                                                                                                                             |
| project_id           | 97ab32e6e26143f9938405a6e36180f7                                                                                                                 |
| revision_number      | 0                                                                                                                                                |
| segment_id           | None                                                                                                                                             |
| service_types        |                                                                                                                                                  |
| subnetpool_id        | None                                                                                                                                             |
| tags                 |                                                                                                                                                  |
| updated_at           | 2020-06-08T13:45:55Z                                                                                                                             |
+----------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
stack@mjozefcz-tempest-plugin-failed-install:~/neutron/neutron$


because of the function 'is_dhcp_options_ignored()' the DHCP options for IPv6 subnets are not added to the IPv6 subnet, while it is created with ipv6_address_mode == 'slaac'.
https://review.opendev.org/#/c/461005/4/networking_ovn/common/utils.py

I mocked this function to return "True" in all cases and the DHCP options are inserted after it.