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Refs

Refs model dependencies between Kubernetes resources as directed edges in Hydra's dependency graph.

Contents

  • Ref Types — direct, indirect, runtime, regarding
  • Ref Parsers — How dependencies are discovered from manifests
  • Ref Tags — Behavioral markers: backup, uninstall, bootstrap-guard
  • Ref Labels — Semantic categories: namespace, crd, controller, owner
  • Ref Attributes — Origin tracking and metadata
  • Writing Custom Refs — Creating your own ref-parsers

Overview

A ref is a directed edge from one Kubernetes resource to another, representing a dependency:

Source ──ref──▶ Target
(depends on)

Refs enable Hydra to: - Apply resources in dependency order - Uninstall resources in reverse dependency order - Include related resources in backups - Visualize relationships in the TUI

Quick Example

A Deployment depends on its ServiceAccount:

apps/v1/Deployment/default/myapp
  ──[direct, label:serviceaccount]──▶ v1/ServiceAccount/default/myapp

Visualizing Refs

# List transitive references (local)
hydra local refs prod apps/v1/Deployment/default/myapp

# List transitive references (with cluster state)
hydra gitops refs prod apps/v1/Deployment/default/myapp

# Interactive TUI
hydra local inspect prod
hydra gitops inspect prod

Prerequisites