collectd/files/backend/http.conf

<LoadPlugin write_http>
  Globals false
</LoadPlugin>

<Plugin write_http>
  <URL "http://{{ backend.host }}:{{ backend.port }}">
    Format "{{ backend.get('format', 'json')|upper }}"
    StoreRates {{ backend.get('store_rates', True)|lower }}
  </URL>
</Plugin>