debian-9 clear out interfaces when static ip

roles/network/tasks/debian.yml

@@ -49,6 +49,13 @@
             src=network/debian-auto
   when: iiab_wan_iface != "none" and is_debian_9
 
+- name: Clearing out /etc/network/interfaces for static addresses (is_debian_9)
+  lineinfile:
+      state: absent
+      path: /etc/network/interfaces
+      regexp: "{{ iiab_wan_iface }}"
+  when: wan_ip != "dhcp" and iiab_wan_iface != "none" and is_debian_9
+
 - name: bind may be affected
   service: name={{ dns_service }} state=stopped
   when: named_install and dnsmasq_enabled

roles/network/templates/network/systemd.j2

@@ -34,7 +34,7 @@ iface {{ iiab_wan_iface }} inet dhcp
 {% endif %}
 # end dhcp clients
 # static wan
-{% if wan_ip != "dhcp" and dhcpcd_result != "enabled" and wan_in_interfaces == "false" %}
+{% if wan_ip != "dhcp" and dhcpcd_result != "enabled" %}
 auto {{ iiab_wan_iface }}
 iface {{ iiab_wan_iface }} inet static
     address {{ wan_ip }}