Hiera is a built-in key-value configuration data lookup
system, used for separating data from Puppet code.
About Hiera Puppet’s strength is in reusable code. Code that serves many needs must be configurable: put site-specific information in external configuration data files, rather than in the code itself.
Getting started with Hiera This page introduces the basic concepts and tasks to get you started with Hiera, including how to create a hiera.yaml config file and write data. It is the foundation for understanding the more advanced topics described in the rest of the Hiera documentation.
Configuring Hiera The Hiera configuration file is called hiera.yaml. It configures the hierarchy for a given layer of data.
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.
Upgrading to Hiera 5 Upgrading to Hiera 5 offers some major advantages. A real environment data layer means changes to your hierarchy are now routine and testable, using multiple backends in your hierarchy is easier and you can make a custom backend.