- Validate config during role run (won't restart service with a faulty config).

tasks/main.yml

@@ -35,6 +35,7 @@
       owner: root
       group: 0
       mode: 0o0644
+      validate: '{{ dhcp_conf_validate[ansible_os_family]|default(omit) }}'
   notify:
       - Restart ISC DHCP server
 

vars/main.yml

@@ -16,3 +16,6 @@ dhcp_user:
 dhcp_conf_file:
     OpenBSD: /etc/dhcpd.conf
     Debian: /etc/dhcp/dhcpd.conf
+
+dhcp_conf_validate:
+    Debian: dhcpd -t