Replace kube-master with kube_control_plane (#7256)

This replaces kube-master with kube_control_plane because of [1]:

  The Kubernetes project is moving away from wording that is
  considered offensive. A new working group WG Naming was created
  to track this work, and the word "master" was declared as offensive.
  A proposal was formalized for replacing the word "master" with
  "control plane". This means it should be removed from source code,
  documentation, and user-facing configuration from Kubernetes and
  its sub-projects.

NOTE: The reason why this changes it to kube_control_plane not
      kube-control-plane is for valid group names on ansible.

[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation

roles/kubernetes-apps/ingress_controller/cert_manager/tasks/main.yml

@@ -5,7 +5,7 @@
     path: "{{ kube_config_dir }}/addons/cert_manager"
     state: absent
   when:
-    - inventory_hostname == groups['kube-master'][0]
+    - inventory_hostname == groups['kube_control_plane'][0]
   tags:
     - upgrade
 
@@ -14,7 +14,7 @@
     {{ bin_dir }}/kubectl delete namespace {{ cert_manager_namespace }}
   ignore_errors: yes
   when:
-    - inventory_hostname == groups['kube-master'][0]
+    - inventory_hostname == groups['kube_control_plane'][0]
   tags:
     - upgrade
 
@@ -26,7 +26,7 @@
     group: root
     mode: 0755
   when:
-    - inventory_hostname == groups['kube-master'][0]
+    - inventory_hostname == groups['kube_control_plane'][0]
 
 - name: Cert Manager | Templates list
   set_fact:
@@ -54,7 +54,7 @@
   with_items: "{{ cert_manager_templates }}"
   register: cert_manager_manifests
   when:
-    - inventory_hostname == groups['kube-master'][0]
+    - inventory_hostname == groups['kube_control_plane'][0]
 
 - name: Cert Manager | Apply manifests
   kube:
@@ -65,12 +65,12 @@
     state: "latest"
   with_items: "{{ cert_manager_manifests.results }}"
   when:
-    - inventory_hostname == groups['kube-master'][0]
+    - inventory_hostname == groups['kube_control_plane'][0]
 
 - name: Cert Manager | Wait for Webhook pods become ready
   command: "{{ bin_dir }}/kubectl wait po --namespace={{ cert_manager_namespace }} --selector app=webhook --for=condition=Ready --timeout=600s"
   register: cert_manager_webhook_pods_ready
-  when: inventory_hostname == groups['kube-master'][0]
+  when: inventory_hostname == groups['kube_control_plane'][0]
 
 - name: Cert Manager | Create ClusterIssuer manifest
   template:
@@ -78,7 +78,7 @@
     dest: "{{ kube_config_dir }}/addons/cert_manager/clusterissuer-cert-manager.yml"
   register: cert_manager_clusterissuer_manifest
   when:
-    - inventory_hostname == groups['kube-master'][0] and cert_manager_webhook_pods_ready is succeeded
+    - inventory_hostname == groups['kube_control_plane'][0] and cert_manager_webhook_pods_ready is succeeded
 
 - name: Cert Manager | Apply ClusterIssuer manifest
   kube:
@@ -86,4 +86,4 @@
     kubectl: "{{ bin_dir }}/kubectl"
     filename: "{{ kube_config_dir }}/addons/cert_manager/clusterissuer-cert-manager.yml"
     state: "latest"
-  when: inventory_hostname == groups['kube-master'][0] and cert_manager_clusterissuer_manifest is succeeded
+  when: inventory_hostname == groups['kube_control_plane'][0] and cert_manager_clusterissuer_manifest is succeeded