add retries for calico/canal etcd commands (#2007)

roles/network_plugin/canal/tasks/main.yml

@@ -29,6 +29,8 @@
     {{ 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 }}" } }'
+  retries: 4
+  delay: "{{ retry_stagger | random + 3 }}"
   delegate_to: "{{groups['etcd'][0]}}"
   changed_when: false
   run_once: true