Worth noting that this can cause an issue in test_sans:

=================================== FAILURES ===================================
__________________________________ test_sans ___________________________________
Traceback (most recent call last):
  File "/home/ubuntu/k8s-validation/jobs/integration/validation.py", line 1071, in test_sans
    await retry_async_with_timeout(
  File "/home/ubuntu/k8s-validation/jobs/integration/utils.py", line 202, in retry_async_with_timeout
    raise asyncio.TimeoutError(timeout_msg)
asyncio.exceptions.TimeoutError: extra sans config did not propagate to server certs
------------------------------ Captured log setup ------------------------------
WARNING  juju.client.connection:connection.py:706 unknown facade CAASApplication
WARNING  juju.client.connection:connection.py:730 unexpected facade CAASApplication found, unable to decipher version to use
WARNING  juju.client.connection:connection.py:706 unknown facade CAASApplicationProvisioner
WARNING  juju.client.connection:connection.py:730 unexpected facade CAASApplicationProvisioner found, unable to decipher version to use
WARNING  juju.client.connection:connection.py:706 unknown facade CAASFirewallerEmbedded
WARNING  juju.client.connection:connection.py:730 unexpected facade CAASFirewallerEmbedded found, unable to decipher version to use
WARNING  juju.client.connection:connection.py:706 unknown facade CAASModelOperator
WARNING  juju.client.connection:connection.py:730 unexpected facade CAASModelOperator found, unable to decipher version to use
WARNING  juju.client.connection:connection.py:724 unknown common facade version for CAASUnitProvisioner
WARNING  juju.client.connection:connection.py:706 unknown facade CharmHub
WARNING  juju.client.connection:connection.py:730 unexpected facade CharmHub found, unable to decipher version to use
WARNING  juju.model:model.py:905 unknown delta type: id
- generated xml file: /home/ubuntu/project/generated/kubernetes/k8s-suite/test_sans-junit.xml -
----- generated html file: file:///home/ubuntu/k8s-validation/report.html ------
=========================== short test summary info ============================
FAILED jobs/integration/validation.py::test_sans - asyncio.exceptions.Timeout...
======================== 1 failed in 606.01s (0:10:06) =========================

var/log/juju/unit-kubernetes-master-0.log:

2021-08-05 13:47:09 INFO unit.kubernetes-master/0.juju-log server.go:314 Executing ['kubectl', '--kubeconfig=/root/.kube/config', 'get', 'secrets', '-n', 'kube-system', '--field-selector', 'type=juju.is/token-auth', '-o', 'json']
2021-08-05 13:47:09 WARNING unit.kubernetes-master/0.update-status logger.go:60 The connection to the server 192.168.33.170:6443 was refused - did you specify the right host or port?
2021-08-05 13:47:09 INFO unit.kubernetes-master/0.juju-log server.go:314 Executing ['kubectl', '--kubeconfig=/root/.kube/config', 'get', 'secrets', '-n', 'kube-system', '--field-selector', 'type=juju.is/token-auth', '-o', 'json']
2021-08-05 13:47:09 WARNING unit.kubernetes-master/0.update-status logger.go:60 The connection to the server 192.168.33.170:6443 was refused - did you specify the right host or port?
2021-08-05 13:47:09 INFO unit.kubernetes-master/0.juju-log server.go:314 Executing ['kubectl', '--kubeconfig=/root/.kube/config', 'get', 'secrets', '-n', 'kube-system', '--field-selector', 'type=juju.is/token-auth', '-o', 'json']
2021-08-05 13:47:09 WARNING unit.kubernetes-master/0.update-status logger.go:60 The connection to the server 192.168.33.170:6443 was refused - did you specify the right host or port?