how keda manager the hpa res which it created ？

[sunnoy]

When I delete the hpa resource created by keda, it will be created automatically，

when i comment this line of code

keda/controllers/scaledobject_controller.go

Line 106 in 347e897

Owns(&autoscalingv2beta2.HorizontalPodAutoscaler{}).

it will don‘t created automatically，How does keda implement this logic?

[zroubalik]

You should check Kubernetes Operator Pattern.

https://www.redhat.com/en/topics/containers/what-is-a-kubernetes-operator

[sunnoy]

keda/controllers/hpa.go

Line 99 in 347e897

if err := controllerutil.SetControllerReference(scaledObject, hpa, r.Scheme); err != nil {

may be this

[sunnoy]

keda/controllers/hpa.go

Line 99 in 347e897

if err := controllerutil.SetControllerReference(scaledObject, hpa, r.Scheme); err != nil {

[zroubalik]

that's just reference, the actual logic is in reconciler loop:

keda/controllers/scaledobject_controller.go

Lines 203 to 226 in 347e897

	// Create a new HPA or update existing one according to ScaledObject
	newHPACreated, err := r.ensureHPAForScaledObjectExists(logger, scaledObject, &gvkr)
	if err != nil {
	return "Failed to ensure HPA is correctly created for ScaledObject", err
	}
	scaleObjectSpecChanged := false
	if !newHPACreated {
	// Lets Check whether ScaledObject generation was changed, ie. there were changes in ScaledObject.Spec
	// if it was changed we should start a new ScaleLoop
	// (we can omit this check if a new HPA was created, which fires new ScaleLoop anyway)
	scaleObjectSpecChanged, err = r.scaledObjectGenerationChanged(logger, scaledObject)
	if err != nil {
	return "Failed to check whether ScaledObject's Generation was changed", err
	}
	}
	// Notify ScaleHandler if a new HPA was created or if ScaledObject was updated
	if newHPACreated || scaleObjectSpecChanged {
	if r.requestScaleLoop(logger, scaledObject) != nil {
	return "Failed to start a new scale loop with scaling logic", err
	}
	logger.Info("Initializing Scaling logic according to ScaledObject Specification")
	}
	return "ScaledObject is defined correctly and is ready for scaling", nil

[sunnoy]

thks