gate failure "Certificate did not match expected hostname"

[Corey Bryant]

This can be seen here:
https://review.opendev.org/c/openstack/charm-masakari-monitors/+/811134

as well as here:
https://review.opendev.org/c/openstack/charm-masakari-monitors/+/810525

This appears to only affect focal-victoria and above.

2021-10-05 12:11:50.449789 | bionic-medium | 2021-10-05 12:11:50 [WARNING] Certificate did not match expected hostname: 172.16.255.181. Certificate: {'subject': ((('commonName', 'juju-2c5f39-zaza-75fabbf52a3f-12.project.serverstack'),),), 'issuer': ((('commonName', 'Vault Intermediate Certificate Authority (charm-pki-local)'),),), 'version': 3, 'serialNumber': '33DB71F184BBC89CA8F1218AE36393446D258EF8', 'notBefore': 'Oct 5 10:35:00 2021 GMT', 'notAfter': 'Oct 5 09:35:30 2022 GMT', 'subjectAltName': (('DNS', 'juju-2c5f39-zaza-75fabbf52a3f-12.project.serverstack'), ('IP Address', '172.16.255.223')), 'caIssuers': ('http://172.16.255.51:8200/v1/charm-pki-local/ca',), 'crlDistributionPoints': ('http://172.16.255.51:8200/v1/charm-pki-local/crl',)}

2021-10-05 12:11:51.491881 | bionic-medium | 2021-10-05 12:11:51 [INFO] ======================================================================
2021-10-05 12:11:51.492064 | bionic-medium | 2021-10-05 12:11:51 [INFO] ERROR: test_instance_failover (zaza.openstack.charm_tests.masakari.tests.MasakariTest)
2021-10-05 12:11:51.492164 | bionic-medium | 2021-10-05 12:11:51 [INFO] Test masakari managed guest migration.
2021-10-05 12:11:51.492270 | bionic-medium | 2021-10-05 12:11:51 [INFO] ----------------------------------------------------------------------
2021-10-05 12:11:51.492403 | bionic-medium | 2021-10-05 12:11:51 [INFO] Traceback (most recent call last):
2021-10-05 12:11:51.492553 | bionic-medium | 2021-10-05 12:11:51 [INFO] File "/home/ubuntu/src/review.opendev.org/openstack/charm-masakari-monitors/build/builds/masakari-monitors/.tox/func-target/lib/python3.6/site-packages/urllib3/connectionpool.py", line 706, in urlopen
2021-10-05 12:11:51.492660 | bionic-medium | 2021-10-05 12:11:51 [INFO] chunked=chunked,
2021-10-05 12:11:51.492813 | bionic-medium | 2021-10-05 12:11:51 [INFO] File "/home/ubuntu/src/review.opendev.org/openstack/charm-masakari-monitors/build/builds/masakari-monitors/.tox/func-target/lib/python3.6/site-packages/urllib3/connectionpool.py", line 382, in _make_request
2021-10-05 12:11:51.492932 | bionic-medium | 2021-10-05 12:11:51 [INFO] self._validate_conn(conn)
2021-10-05 12:11:51.493019 | bionic-medium | 2021-10-05 12:11:51 [INFO] File "/home/ubuntu/src/review.opendev.org/openstack/charm-masakari-monitors/build/builds/masakari-monitors/.tox/func-target/lib/python3.6/site-packages/urllib3/connectionpool.py", line 1010, in _validate_conn
2021-10-05 12:11:51.493103 | bionic-medium | 2021-10-05 12:11:51 [INFO] conn.connect()
2021-10-05 12:11:51.493186 | bionic-medium | 2021-10-05 12:11:51 [INFO] File "/home/ubuntu/src/review.opendev.org/openstack/charm-masakari-monitors/build/builds/masakari-monitors/.tox/func-target/lib/python3.6/site-packages/urllib3/connection.py", line 469, in connect
2021-10-05 12:11:51.493271 | bionic-medium | 2021-10-05 12:11:51 [INFO] _match_hostname(cert, self.assert_hostname or server_hostname)
2021-10-05 12:11:51.493352 | bionic-medium | 2021-10-05 12:11:51 [INFO] File "/home/ubuntu/src/review.opendev.org/openstack/charm-masakari-monitors/build/builds/masakari-monitors/.tox/func-target/lib/python3.6/site-packages/urllib3/connection.py", line 542, in _match_hostname
2021-10-05 12:11:51.493525 | bionic-medium | 2021-10-05 12:11:51 [INFO] match_hostname(cert, asserted_hostname)
2021-10-05 12:11:51.493743 | bionic-medium | 2021-10-05 12:11:51 [INFO] File "/usr/lib/python3.6/ssl.py", line 327, in match_hostname
2021-10-05 12:11:51.493872 | bionic-medium | 2021-10-05 12:11:51 [INFO] % (hostname, ', '.join(map(repr, dnsnames))))
2021-10-05 12:11:51.493968 | bionic-medium | 2021-10-05 12:11:51 [INFO] ssl.CertificateError: hostname '172.16.255.181' doesn't match either of 'juju-2c5f39-zaza-75fabbf52a3f-13.project.serverstack', '172.16.255.172'