Support dynamic kubelet config

https://kubernetes.io/blog/2018/07/11/dynamic-kubelet-configuration/

roles/kubernetes/node/tasks/main.yml

@@ -32,6 +32,13 @@
   tags:
     - kubelet
 
+- name: Make sure dynamic kubelet configuration directory is writeable
+  file:
+    path: "{{ dynamic_kubelet_configuration_dir }}"
+    mode: 0600
+    state: directory
+  when: dynamic_kubelet_configuration
+
 - name: Write kubelet config file (kubeadm)
   template:
     src: kubelet.kubeadm.env.j2