openstack tripleo validator run command produces error

Issue

• openstack tripleo validator run --group pre-introspection fail on all tests since update to 16.2.2:

[stack@undercloud-0-rhosp16 cloud]$ openstack tripleo validator run  --group pre-introspection
+--------------------------------------+---------------------------------+--------+------------+-----------------+-------------------+-------------+
| UUID                                 | Validations                     | Status | Host_Group | Status_by_Host  | Unreachable_Hosts | Duration    |
+--------------------------------------+---------------------------------+--------+------------+-----------------+-------------------+-------------+
| 3d7cf395-2027-44a1-99f0-184cc0deb16d | check-cpu                       | FAILED | localhost  | localhost       |                   | 0:00:02.536 |
| 55950bad-b81a-4702-b9a5-abfa5a231503 | check-disk-space                | FAILED | localhost  | localhost       |                   | 0:00:06.631 |
| 7be98b02-6900-4508-a0ed-24961d2cdec2 | check-ram                       | FAILED | localhost  | localhost       |                   | 0:00:01.780 |
| 063b9169-c312-4962-8ab5-b8238d908931 | check-selinux-mode              | FAILED | localhost  | localhost       |                   | 0:00:02.318 |
| f446a51e-fbc2-4c5f-9389-7c7e076adcfe | undercloud-disk-space           | FAILED | undercloud | No host matched |                   |             |
| 652561a3-1e04-4c5c-bf29-93560023a69f | check-network-gateway           | FAILED | undercloud | No host matched |                   |             |
| c0951a14-5371-4004-9dba-a448c4af278f | undercloud-neutron-sanity-check | FAILED | undercloud | No host matched |                   |             |
| fb90f73d-5321-4ba9-bd1c-774c8c8a22b3 | undercloud-tokenflush           | FAILED | undercloud | No host matched |                   |             |
| fe33cd14-9fe5-4c9e-b969-056a7b3803ca | ctlplane-ip-range               | FAILED | undercloud | No host matched |                   |             |
| 6321047a-d472-4b4d-be53-95183c465e8f | dhcp-introspection              | FAILED | undercloud | No host matched |                   |             |
+--------------------------------------+---------------------------------+--------+------------+-----------------+-------------------+-------------+

• The above will happen with all "openstack validator run" calls and is not limited to a single validator group. This issue shows up with the Status_by_Host being displayed as "No host matched" because no ansible inventory was available for "undercloud" but will also affect the overcloud validations.