Understanding Hiera

Hiera is a feature of Puppet that allows data to be stored and subsequently queried from any number of file formats (“back-end” structures). These structures may be in a number of different formats, the most preferable being YAML, which is a readable properties file format with hierarchical structure support. The value of Hiera to the PeopleSoft modules is that it allows separation of the data from the code that performs the actual system configuration. In the context of a PeopleSoft environment, the database connectivity information and any other custom configuration settings to be applied to the Application Server domain are placed in a Hiera data file. Any number of domains with varying configuration settings can be represented in a Hiera data file. Hiera data files can be associated with a particular environment such as Dev, Test or Production. A Production Hiera data file may contain connectivity information for a single database with a number of Application Server domains. A Dev Hiera data file on the other hand may only contain a single Application Server domain and may have specific configuration features enabled such as the Work Station Listener process for three-tier PeopleSoft connections. This ability to define all abstractions of the PeopleSoft environment in Hiera completely decouples the runtime characteristics of your environment from the code that actually creates it. This is a very powerful feature.