Writing new data backends

You can extend Hiera to look up values in data sources, for example, a PostgreSQL database table, a custom web app, or a new kind of structured data file.

To teach Hiera how to talk to other data sources, write a custom backend.

Writing a custom backend is an advanced topic. Before proceeding, make sure you really need it. It is also worth asking the puppet-dev mailing list or Slack channel to see whether there is one you can re-use, rather than starting from scratch.