Use api lookup for kubelet hostname when using cloudprovider (#1686)

The value cannot be determined properly via local facts, so
checking k8s api is the most reliable way to look up what hostname
is used when using a cloudprovider.

roles/network_plugin/calico/tasks/main.yml

@@ -6,6 +6,13 @@
     enabled: yes
   failed_when: false
 
+- name: Calico | Get kubelet hostname
+  shell: >-
+    kubectl get node -o custom-columns='NAME:.metadata.name,INTERNAL-IP:.status.addresses[?(@.type=="InternalIP")].address'
+    | egrep "[[:space:]]{{ ansible_all_ipv4_addresses | join('[[:space:]]|[[:space:]]') }}[[:space:]]*$" | cut -d" " -f1
+  register: calico_kubelet_name
+  when: cloud_provider is defined
+
 - name: Calico | Write Calico cni config
   template:
     src: "cni-calico.conf.j2"

roles/network_plugin/calico/templates/cni-calico.conf.j2

@@ -1,7 +1,7 @@
 {
   "name": "calico-k8s-network",
 {% if cloud_provider is defined %}
-  "nodename": "{{ inventory_hostname }}",
+  "nodename": "{{ calico_kubelet_name.stdout }}",
 {% else %}
   "nodename": "{{ ansible_hostname }}",
 {% endif %}