Add /var/lib/cni to kubelet

Necessary to persist this directory for host-local IPAM used by Canal
Add pre-upgrade task to copy /var/lib/cni out of old kubelet.

roles/kubernetes/node/tasks/main.yml

@@ -4,6 +4,9 @@
       {%- if inventory_hostname in groups['kube-master'] and inventory_hostname not in groups['kube-node'] -%}true{%- else -%}false{%- endif -%}
   tags: facts
 
+- include: pre_upgrade.yml
+  tags: kubelet
+
 - include: install.yml
   tags: kubelet
 

roles/kubernetes/node/tasks/pre_upgrade.yml

@@ -0,0 +1,6 @@
+---
+- name: "Pre-upgrade | copy /var/lib/cni from kubelet"
+  command: docker cp kubelet:/var/lib/cni /var/lib/cni
+  args:
+    creates: "/var/lib/cni"
+  failed_when: false