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Concepts#

Core Resources#

ClusterResourceSupervisor#

A ClusterResourceSupervisor is a cluster-scoped custom resource that defines hibernation schedules for multiple namespaces across the cluster. It enables platform administrators to centrally manage cost-saving policies by targeting namespaces either explicitly by name, dynamically via Kubernetes label selectors, or through ArgoCD AppProjects. The operator scales down Deployments and StatefulSets to zero during sleep windows and restores them to their original replica counts during wake windows. Its rich status field tracks watched, ignored, and sleeping namespaces along with preserved replica states for reliable recovery.

ResourceSupervisor#

A ResourceSupervisor is a namespace-scoped custom resource that allows application teams or namespace owners to define hibernation schedules within their own namespace. It provides a lightweight, self-service mechanism to scale workloads down and up based on cron expressions—without requiring cluster-level permissions. This resource is ideal for teams managing staging, CI/CD preview, or demo environments that should run only during specific hours.

Hibernation Schedule#

The Hibernation Schedule is defined via two optional cron expressions:

  • sleepSchedule (required): Specifies when workloads should be scaled to zero.
  • wakeSchedule (optional): Specifies when workloads should be restored.

If wakeSchedule is omitted, resources remain asleep indefinitely until manually woken or the CR is updated. Both schedules use standard Unix cron format (e.g., "0 18 * * 1-5").

Sleeping State#

The Sleeping State refers to the condition where a Deployment or StatefulSet has been scaled to 0 replicas by the Hibernation Operator. The original replica count is preserved in the CR’s status.sleepingNamespaces field to ensure accurate restoration. Only workloads explicitly targeted by a supervisor are affected—everything else remains untouched.

Integration Concepts#

ArgoCD AppProject Integration#

When a ClusterResourceSupervisor specifies argocd.appProjects, the operator automatically discovers all namespaces managed by those ArgoCD AppProjects and applies hibernation to them. This enables GitOps-native hibernation policies aligned with application boundaries rather than infrastructure boundaries.

Label-Based Namespace Selection#

Instead of listing namespaces individually, platform teams can use Kubernetes-standard label selectors (matchLabels and matchExpressions) to dynamically include namespaces that match certain criteria (e.g., env: dev, team: frontend). This supports scalable, policy-driven hibernation in large clusters.