Add etcd TLS support

roles/network_plugin/flannel/tasks/main.yml

@@ -1,9 +1,11 @@
 ---
-- name: Flannel | Write flannel configuration
-  template:
-    src: network.json
-    dest: /etc/flannel-network.json
-    backup: yes
+- name: Flannel | Set Flannel etcd configuration
+  command: |-
+    {{ bin_dir }}/etcdctl --peers={{ etcd_access_addresses }} \
+    set /{{ cluster_name }}/network/config \
+    '{ "Network": "{{ kube_pods_subnet }}", "SubnetLen": {{ kube_network_node_prefix }}, "Backend": { "Type": "{{ flannel_backend_type }}" } }'
+  delegate_to: "{{groups['etcd'][0]}}"
+  run_once: true
 
 - name: Flannel | Create flannel pod manifest
   template: