setting join group to a variable

README.md

@@ -46,6 +46,10 @@ Extra args to pass to `kubeadm init` during K8s control plane initialization. E.
 
 Extra args to pass to the generated `kubeadm join` command during K8s node initialization. E.g. to ignore certain preflight errors like swap being enabled, set this to: `--ignore-preflight-errors=Swap`
 
+    kubernetes_join_group: 'all'
+
+The scope to which group the join command will be applied.  The default is set to 'all' but you may want to specify a specific group if there are more than one cluster in an inventory (in which case `kubernetes_role` may be defined in separate clusters, which are not relevant to a particular execution).
+
     kubernetes_allow_pods_on_master: true
 
 Whether to remove the taint that denies pods from being deployed to the Kubernetes master. If you have a single-node cluster, this should definitely be `True`. Otherwise, set to `False` if you want a dedicated Kubernetes master which doesn't run any other pods.

defaults/main.yml

@@ -17,6 +17,7 @@ kubernetes_role: master
 kubernetes_kubelet_extra_args: ""
 kubernetes_kubeadm_init_extra_opts: ""
 kubernetes_join_command_extra_opts: ""
+kubernetes_join_group: 'all'
 
 kubernetes_allow_pods_on_master: true
 kubernetes_enable_web_ui: true

tasks/main.yml

@@ -50,7 +50,7 @@
   when: kubernetes_join_command_result.stdout is defined
   delegate_to: "{{ item }}"
   delegate_facts: true
-  with_items: "{{ groups['all'] }}"
+  with_items: "{{ groups[kubernetes_join_group] }}"
 
 - include_tasks: node-setup.yml
   when: kubernetes_role == 'node'