handle different netplan file name

roles/network/tasks/sysd-netd-debian.yml

@@ -38,13 +38,18 @@
     wan_cidr: "{{ CIDR.stdout }}"
   when: wan_ip != "dhcp"
 
+- name: Figure out netplan file name on Ubuntu 18
+  shell: ls /etc/netplan
+  register: netplan
+  when: is_ubuntu_18
+
 # ICO will always set gui_static_wan_ip away from the default of 'unset' while
 # gui_static_wan turns dhcp on/off through wan_ip in computed_network and
 # overrides gui_static_wan_ip that is present. Changing wan_ip in local_vars
 # is a oneway street to static.
 - name: Supply static template
   template:
-    dest:  /etc/netplan/50-cloud-init.yaml
+    dest:  /etc/netplan/{{ netplan.stdout }}
     src: network/cloud-init.j2
     backup: no
   when: (wan_ip != "dhcp" or gui_static_wan_ip == "undefined") and is_ubuntu_18