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

roles/kubernetes/node/templates/kubelet.kubeadm.env.j2

@@ -48,6 +48,9 @@ KUBELET_HOSTNAME="--hostname-override={{ kube_override_hostname }}"
 {% else %}
 --fail-swap-on={{ kubelet_fail_swap_on|default(true)}} \
 {% endif %}
+{% if dynamic_kubelet_configuration %}
+--dynamic-config-dir={{ dynamic_kubelet_configuration_dir }} \
+{% endif %}
 --runtime-cgroups={{ kubelet_runtime_cgroups }} --kubelet-cgroups={{ kubelet_kubelet_cgroups }} \
 {% endset %}