$TTL 86400
@ IN SOA ns1.example.com. hostmaster.example.com. (
         {{ serial }} ; Serial
         4H ; Refresh
         1H ; Retry
         1W ; Expire
         1D ) ; Minimum TTL
@ IN NS ns1.example.com.
@ IN NS ns2.example.com.

{% for record, rrs in records.items() -%}
{% for rr in rrs -%}
{% if not record.endswith('.') -%}
{% set record = record + "." -%}
{% endif -%}
{% if rr.type in ['PTR'] and not rr.rr.endswith('.') -%}
{% set update = rr.update({'rr':rr.rr + "."}) -%}
{% endif -%}
{{ record }} IN {{ rr.type }} {{ rr.rr }}
{% endfor -%}
{% endfor -%}