kubernetes-operator

Controller-Runtime Patterns

Reconciler Structure

• Implement reconcile.Reconciler interface
• Always accept and propagate context.Context
• Return ctrl.Result{} with appropriate requeue:
  • Result{} — success, no requeue
  • Result{RequeueAfter: 30 * time.Second} — delayed retry
  • Result{Requeue: true} — immediate retry
• Never return an error for expected/permanent failures — log and return Result{}
• Return errors only for transient failures that should be retried

CRD Design

• Group: <domain>.example.com/v1alpha1 → v1beta1 → v1
• Status subresource always enabled
• Use status conditions following metav1.Condition pattern:
  • Type, Status (True/False/Unknown), Reason, Message, LastTransitionTime
• Printer columns for kubectl get output
• Validation via CEL expressions in CRD markers