Provide empty list of gateways if none are set

CHANGES.rst

@@ -4,7 +4,7 @@ Changelog
 v0.1.1
 ------
 
-*Unreleased*
+*Released: 2015-10-15*
 
 - Make sure that files specified in ``dhcpd_includes`` list exist before the
   DHCP server is restarted. [drybjed]
@@ -21,6 +21,9 @@ v0.1.1
 - Change the way role gathers the list of nameservers to avoid issue with
   ``sed`` command in shell module. [drybjed]
 
+- Provide empty list of relay servers if default IPv4 gateway is not defined.
+  [drybjed]
+
 v0.1.0
 ------
 

defaults/main.yml

@@ -44,7 +44,9 @@ dhcpd_base_packages_map:
 # .. envvar:: dhcpd_relay_servers
 #
 # List of DHCP servers which should receive the relayed packets
-dhcpd_relay_servers: [ '{{ ansible_default_ipv4.gateway }}' ]
+dhcpd_relay_servers: [ '{{ ansible_default_ipv4.gateway
+                           if (ansible_default_ipv4.gateway|d())
+                           else [] }}' ]
 
 
 # .. envvar:: dhcpd_relay_interfaces