Add radvd role

roles/radvd/templates/radvd.conf.j2

@@ -0,0 +1,20 @@
+{% for iface in interfaces
+    | defaultattr('mgmt_only') | rejectattr('mgmt_only')
+    | selectattr('enabled') %}
+{% for address in iface.ip_addresses | selectattr("family.value", "==", 6) %}
+{# get the gateway for this subnet #}
+{% set subnet = address.address | ipaddr('subnet') %}
+{% set prefix = prefixes | selectattr('prefix', '==', subnet) | first %}
+{% set gateway = prefix.custom_fields.gateway.address %}
+{# if we are gateway, send RAs on this interface #}
+{% if gateway is defined and gateway == address.address %}
+interface {{ iface.name }} {
+	AdvSendAdvert on;
+	prefix ::/64;
+	RDNSS {{ dns6 | join(' ') }} { };
+	DNSSL {{ domain }} { };
+};
+
+{% endif %}
+{% endfor %}
+{% endfor %}