nodepool-functional-k8s: switch to microk8s

Switch this job to use microk8s, which should be more stable than
minikube on our Ubuntu testing hosts.

Depends-on: https://review.opendev.org/c/zuul/zuul-jobs/+/866953
Change-Id: I8e76581ea5cf4a4241aec48bc59086d7f17cd72a

.zuul.yaml

@@ -4,7 +4,6 @@
     name: nodepool-functional-k8s
     pre-run: playbooks/nodepool-functional-k8s/pre.yaml
     run: playbooks/nodepool-functional-k8s/run.yaml
-    post-run: playbooks/nodepool-functional-k8s/post.yaml
     required-projects:
       - zuul/nodepool
     nodeset: ubuntu-jammy

nodepool/tests/fixtures/functional/kubernetes/basic.yaml

@@ -15,9 +15,9 @@ labels:
     min-ready: 1
 
 providers:
-  - name: minikube
+  - name: microk8s
     driver: kubernetes
-    context: minikube
+    context: microk8s
     pools:
       - name: main
         max-servers: 2
@@ -26,4 +26,4 @@ providers:
             type: namespace
           - name: pod-fedora
             type: pod
-            image: quay.io/fedora/fedora:34-x86_64
+            image: quay.io/fedora/fedora:37-x86_64

playbooks/nodepool-functional-k8s/post.yaml

@@ -1,10 +0,0 @@
-- hosts: all
-  vars:
-    minikube_log: '{{ ansible_user_dir }}/zuul-output/logs/minikube.txt'
-
-  tasks:
-    - name: Produce minikube log
-      become: yes
-      shell: '/tmp/minikube logs > {{ minikube_log }}'
-      environment:
-        MINIKUBE_HOME: "{{ ansible_user_dir }}"

playbooks/nodepool-functional-k8s/pre.yaml

@@ -5,4 +5,8 @@
       zookeeper_use_tls: true
     - role: ensure-tox
     - role: ensure-kubernetes
-      docker_version: 18.06.1~ce~3-0~ubuntu
+      ensure_kubernetes_type: microk8s
+      # k8s > 1.23 changed the way the service account tokens
+      # are auto-generated; see
+      #  https://storyboard.openstack.org/#!/story/2010224
+      ensure_kubernetes_microk8s_channel: '1.23/stable'

tox.ini

@@ -1,11 +1,9 @@
 [tox]
 minversion = 3.1
-skipsdist = True
 envlist = pep8,py3
 ignore_basepython_conflict = True
 
 [testenv]
-basepython = python3
 # Set STATSD env variables so that statsd code paths are tested.
 setenv = STATSD_HOST=localhost
          STATSD_PORT=8125
@@ -60,7 +58,6 @@ commands = stestr --test-path ./nodepool/tests/functional/kubernetes run --no-su
            stestr slowest
 
 [testenv:functional_openshift]
-basepython = python3
 commands = stestr --test-path ./nodepool/tests/functional/openshift run --no-subunit-trace {posargs}
            stestr slowest