Unite Dev & Ops Around a Single Source of Truth

Hiera is a tool for managing and separating configuration data from config code, allowing a single source of configuration truth.

Benefits include Keeping config DRY (Don't Repeat Yourself), using defaults, inheritances, and overrides to centralize config complexity in one location and make the consumption simple and easily understood. 

GitOps and centralized config make it easier to coordinate changes and reduce the risk of conflicting changes that could cause problems.

While Git is great for managing the templates, there is a need to complement GitOps with a hierarchical config data source to supply injectable parameters and secrets into the templates. Centralized configuration is a critical component of GitOps.