timesyncd: rename variable ntp_servers to timesyncd_ntp_servers and check for minimum number of elements

timesyncd/defaults/main.yml

@@ -1,3 +1,3 @@
 ---
-ntp_servers:
-- 'ntp.evolix.net'
+timesyncd_ntp_servers:
+  - 'ntp.evolix.net'

timesyncd/tasks/main.yml

@@ -1,4 +1,10 @@
 ---
+
+- name: Verify that at least 1 NTP server is provided
+  ansible.builtin.assert:
+    that: timesyncd_ntp_servers | length > 0
+    msg: The variable timesyncd_ntp_servers must contain at least 1 element
+
 - name: Install systemd-timesyncd package
   ansible.builtin.apt:
     name: systemd-timesyncd

timesyncd/templates/timesyncd.conf.j2

@@ -1,3 +1,3 @@
 # {{ ansible_managed }}
 [Time]
-NTP="{{ ntp_servers | join(' ') }}"
+NTP="{{ timesyncd_ntp_servers | join(' ') }}"