Getting Started

This tutorial series introduces Hydra from the perspective of the CLI modes you use day to day.

Helm knowledge is assumed. Core Helm concepts such as chart values, template rendering, and dependencies are used throughout the tutorial, but not explained separately here.

Hydra Modes

Hydra has three operating modes:

• local — work only with the local GitOps directory
  • inspect rendered manifests for Hydra apps
  • inspect Helm template sources and computed values
• gitops — work with the local GitOps directory and a live Kubernetes connection
  • install, update, and uninstall Hydra apps
• cluster — work only against the current kubectl context
  • these commands do not use a local GitOps directory

This tutorial covers the local commands only.

HYDRA_CONTEXT

HYDRA_CONTEXT tells Hydra which GitOps directory to read. See Concepts: Context and Clusters for the full model.

Unlike KUBECONFIG, the target of HYDRA_CONTEXT is a directory in your GitOps repository. The context contains one subdirectory per cluster.

ArgoCD is optional and is not covered in this tutorial. If you use ArgoCD, one context may also contain an ArgoCD installation that manages the other clusters.

One context can contain multiple clusters, for example all dev servers, with team1, team2, and team3 as clusters inside that context.

Chapters

• Create a Hydra App — set HYDRA_CONTEXT, walk through the first validation errors, and create the first Helm chart for a Hydra app
• Inspect Manifests and Their Templates — inspect rendered manifests, template sources, and filters in a Hydra app chart