refs in Values¶

Defining dependency edges between Kubernetes resources.

Structure¶

global:
  hydra:
    refs:
      <group-name>:
        tag: [<tag>, ...]           # Tags applied to all refs in this group
        priority: 0                 # Optional default ownership priority for all ref-parsers in this group
        label: <string>             # Label applied to all refs
        ref-parsers:
          - predicate: '<CEL>'      # CEL predicate selecting source resources
            ids:                    # Static ID matches (alternative to CEL)
              - '<resource-id>'

Ref Groups¶

Refs are organized into named groups. Each group defines a set of dependency edges from matching resources.

Example: Event Cleanup¶

refs:
  events:
    tag: [uninstall]
    ref-parsers:
      - predicate: 'gvk == "events.k8s.io/v1/Event" && ns == "cert-manager"'

This creates refs to all Events in the cert-manager namespace and tags them for removal during uninstall.

Example: Backup Secrets¶

refs:
  backup-tls:
    tag: [backup]
    ref-parsers:
      - predicate: 'kind == "Secret" && ns == "cert-manager" && name == "ca-key-pair"'

This marks the CA key secret for inclusion in backups.

Example: CRD Management¶

refs:
  crds:
    tag: [uninstall]
    ref-parsers:
      - predicate: 'gvk == "apiextensions.k8s.io/v1/CustomResourceDefinition" && name.startsWith("cert-manager")'

Available Tags¶

Tag	Effect
`[backup]`	Include in `cluster backup create`
`[uninstall]`	Remove during `cluster uninstall`; also assigns cluster-only resources to the matching app when unambiguous
`[uninstall-force]`	Show as force-deletable during `cluster uninstall`; delete with `--force` or skip with `--keep`
`[uninstall-safe]`	Safe to remove without impact

See Refs: Ref Tags for the complete list.

CEL Predicates in Refs¶

The predicate field uses CEL expressions. Available variables:

gvk — Full GVK string (e.g., "apps/v1/Deployment")
kind — Kind only (e.g., "Deployment")
name — Resource name
ns — Namespace
id — Full resource ID

See CEL: Variables for all available variables.

Static ID Matches¶

Instead of CEL predicates, you can match by exact resource ID:

refs:
  namespace:
    tag: [uninstall]
    ref-parsers:
      - ids:
          - 'v1/Namespace//cert-manager'

Common Patterns¶

Pattern	Predicate
All Events in a namespace	`gvk == "events.k8s.io/v1/Event" && ns == "<ns>"`
Specific Secret for backup	`kind == "Secret" && ns == "<ns>" && name == "<name>"`
All CRDs with prefix	`gvk == "apiextensions.k8s.io/v1/CustomResourceDefinition" && name.startsWith("<prefix>")`
All resources in namespace	`ns == "<ns>"`