add support for multiple backends

defaults/main.yml

@@ -10,7 +10,7 @@ powerdns:
     "guardian": "yes"
     "include-dir": "/etc/powerdns/pdns.d"
     "launch":
-    - bind
+      bind: {}
     "master": "no"
     "reuseport": "yes"
     "setgid": pdns

templates/pdns.conf.j2

-{% set array_values = ['allow-axfr-ips', 'launch'] %}
+{% set array_values = ['allow-axfr-ips'] %}
+{% set dict_array_values = ['launch'] %}
 {% for option in powerdns.config.keys()|sort %}
-{{ option }}={% if option in array_values %}{{ powerdns.config[option]|join(',' ) }}{% else %}{{ powerdns.config[option] }}{% endif %}
+{{ option }}={% if option in array_values %}{{ powerdns.config[option]|join(',' ) }}{% elif option in dict_array_values %}{{ powerdns.config[option].keys()|sort()|join(',' ) }}{% else %}{{ powerdns.config[option] }}{% endif %}
 
 {% endfor %}