add variable support

defaults/main.yml

@@ -15,3 +15,4 @@ firewall:
     input: drop
     output: accept
     forward: drop
+  vars: {}

templates/nftables.conf.j2

@@ -19,6 +19,10 @@
 
 flush ruleset
 
+{% for i in firewall.vars %}
+define {{ i }} = { {{ firewall.vars[i]|join(', ') }} }
+{% endfor %}
+
 table inet filter {
 	chain input {
 		type filter hook input priority 0;