Fix etc hosts for cluster nodes

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

roles/kubernetes/preinstall/tasks/etchosts.yml

@@ -3,7 +3,7 @@
   blockinfile:
     dest: /etc/hosts
     block: |-
-      {% for item in groups['all'] -%}{{ hostvars[item]['access_ip'] | default(hostvars[item]['ip'] | default(hostvars[item].ansible_default_ipv4.address)) }}{% if (item != hostvars[item]['ansible_hostname']) %} {{ hostvars[item]['ansible_hostname'] }} {{ hostvars[item]['ansible_hostname'] }}.{{ dns_domain }}{% endif %} {{ item }} {{ item }}.{{ dns_domain }}
+      {% for item in (groups['k8s-cluster'] + groups['etcd'] + groups['calico-rr']|default([]))|unique -%}{{ hostvars[item]['access_ip'] | default(hostvars[item]['ip'] | default(hostvars[item]['ansible_default_ipv4']['address'])) }}{% if (item != hostvars[item]['ansible_hostname']) %} {{ hostvars[item]['ansible_hostname'] }} {{ hostvars[item]['ansible_hostname'] }}.{{ dns_domain }}{% endif %} {{ item }} {{ item }}.{{ dns_domain }}
       {% endfor %}
     state: present
     create: yes