Rename master to control plane - non-breaking changes only (#11394)

K8s is moving away from the "master" terminology, so kubespray should follow the same naming conventions. See 65d886bb30/sig-architecture/naming/recommendations/001-master-control-plane.md

roles/kubernetes/kubeadm/tasks/main.yml

@@ -71,7 +71,7 @@
     owner: "root"
     mode: "0644"
   when:
-    - not is_kube_master
+    - ('kube_control_plane' not in group_names)
     - not kubelet_conf.stat.exists
     - kubeadm_use_file_discovery
 
@@ -81,7 +81,7 @@
     dest: "{{ kube_config_dir }}/kubeadm-client.conf"
     backup: true
     mode: "0640"
-  when: not is_kube_master
+  when: ('kube_control_plane' not in group_names)
 
 - name: Kubeadm | Create directory to store kubeadm patches
   file:
@@ -101,7 +101,9 @@
 - name: Join to cluster if needed
   environment:
     PATH: "{{ bin_dir }}:{{ ansible_env.PATH }}:/sbin"
-  when: not is_kube_master and (not kubelet_conf.stat.exists)
+  when:
+    - ('kube_control_plane' not in group_names)
+    - not kubelet_conf.stat.exists
   block:
 
     - name: Join to cluster
@@ -143,7 +145,7 @@
     backup: true
   when:
     - kubeadm_config_api_fqdn is not defined
-    - not is_kube_master
+    - ('kube_control_plane' not in group_names)
     - kubeadm_discovery_address != kube_apiserver_endpoint | replace("https://", "")
   notify: Kubeadm | restart kubelet
 
@@ -154,7 +156,7 @@
     line: '    server: {{ kube_apiserver_endpoint }}'
     backup: true
   when:
-    - not is_kube_master
+    - ('kube_control_plane' not in group_names)
     - loadbalancer_apiserver is defined
   notify: Kubeadm | restart kubelet
 
@@ -169,8 +171,8 @@
   tags:
     - kube-proxy
 
-# FIXME(mattymo): Need to point to localhost, otherwise masters will all point
-#                 incorrectly to first master, creating SPoF.
+# FIXME(mattymo): Need to point to localhost, otherwise control plane nodes will all point
+#                 incorrectly to first control plane node, creating SPoF.
 - name: Update server field in kube-proxy kubeconfig
   shell: >-
     set -o pipefail && {{ kubectl }} get configmap kube-proxy -n kube-system -o yaml