Use ansible array format instead of dot-notation.

This fixes the ansible error ```'dict object' has no attribute
'ansible_default_ipv4'"}```. Closes #215

roles/etcd/templates/etcd.j2

@@ -6,12 +6,12 @@ ETCD_DATA_DIR="/var/lib/etcd"
 {%             set _dummy = etcd.update({'name':"etcd"+loop.index|string}) %}
 {%         endif %}
 {%     endfor %}
-ETCD_ADVERTISE_CLIENT_URLS="http://{{ hostvars[inventory_hostname]['access_ip'] | default(hostvars[inventory_hostname]['ip'] | default( ansible_default_ipv4.address)) }}:2379"
-ETCD_INITIAL_ADVERTISE_PEER_URLS="http://{{ hostvars[inventory_hostname]['access_ip'] | default(hostvars[inventory_hostname]['ip'] | default( ansible_default_ipv4.address))  }}:2380"
+ETCD_ADVERTISE_CLIENT_URLS="http://{{ hostvars[inventory_hostname]['access_ip'] | default(hostvars[inventory_hostname]['ip'] | default( hostvars[inventory_hostname]['ansible_default_ipv4']['address'])) }}:2379"
+ETCD_INITIAL_ADVERTISE_PEER_URLS="http://{{ hostvars[inventory_hostname]['access_ip'] | default(hostvars[inventory_hostname]['ip'] | default( hostvars[inventory_hostname]['ansible_default_ipv4']['address']))  }}:2380"
 ETCD_INITIAL_CLUSTER_STATE="new"
 ETCD_INITIAL_CLUSTER_TOKEN="k8s_etcd"
-ETCD_LISTEN_PEER_URLS="http://{{ hostvars[inventory_hostname]['ip'] | default( ansible_default_ipv4.address)  }}:2380"
+ETCD_LISTEN_PEER_URLS="http://{{ hostvars[inventory_hostname]['ip'] | default( hostvars[inventory_hostname]['ansible_default_ipv4']['address'])  }}:2380"
 ETCD_NAME="{{ etcd.name }}"
 {% endif %}
-ETCD_INITIAL_CLUSTER="{% for host in groups['etcd'] %}etcd{{ loop.index|string }}=http://{{ hostvars[host]['access_ip'] | default(hostvars[host]['ip'] | default(hostvars[host]['ansible_default_ipv4']['address'])) }}:2380{% if not loop.last %},{% endif %}{% endfor %}"
-ETCD_LISTEN_CLIENT_URLS="http://{{ hostvars[inventory_hostname]['ip'] | default( ansible_default_ipv4.address)  }}:2379,http://127.0.0.1:2379"
+ETCD_INITIAL_CLUSTER="{% for host in groups['etcd'] %}etcd{{ loop.index|string }}=http://{{ hostvars[host]['access_ip'] | default(hostvars[host]['ip'] | default(hostvars[inventory_hostname]['ansible_default_ipv4']['address'])) }}:2380{% if not loop.last %},{% endif %}{% endfor %}"
+ETCD_LISTEN_CLIENT_URLS="http://{{ hostvars[inventory_hostname]['ip'] | default( hostvars[inventory_hostname]['ansible_default_ipv4']['address'])  }}:2379,http://127.0.0.1:2379"