modify ScaleUp policy to allow scale up more than 100%

Author: alt-dima

internal/controller/prescale_controller.go

@@ -394,10 +394,19 @@ func (r *PrescaleReconciler) executePrescale(ctx context.Context, req ctrl.Reque
 
 	// Prescale HPA Spec Metrics CPU AverageUtilization to prescaleSpecCpuUtilization
 	hpa.Spec.Metrics[originalSpecCpuUtilizationIndex].Resource.Target.AverageUtilization = &prescaleSpecCpuUtilization
-	if originalScaleUpStabilizationWindowSeconds != nil {
-		zero := int32(0)
-		hpa.Spec.Behavior.ScaleUp.StabilizationWindowSeconds = &zero
-	}
+
+	// Add ScaleUp policy that will allow to scale up to the percent
+	// TODO: add check if policy already exists before adding and add to OrphanedScaleUpPolicies
+	hpa.Spec.Behavior.ScaleUp.Policies = append(hpa.Spec.Behavior.ScaleUp.Policies, autoscalingv2.HPAScalingPolicy{
+		Type:          autoscalingv2.PercentScalingPolicy,
+		Value:         percent,
+		PeriodSeconds: 5,
+	})
+	zero := int32(0)
+	hpa.Spec.Behavior.ScaleUp.StabilizationWindowSeconds = &zero
+	maxPolicy := autoscalingv2.MaxChangePolicySelect
+	hpa.Spec.Behavior.ScaleUp.SelectPolicy = &maxPolicy
+
 	if err := r.Update(ctx, hpa); err != nil {
 		log.Error(err, "failed to update hpa for prescale")
 		r.Recorder.Event(prescaler, corev1.EventTypeWarning, "FailedUpdateHPA", err.Error())
@@ -482,6 +491,15 @@ func (r *PrescaleReconciler) revertHPA(ctx context.Context, req ctrl.Request, pr
 	if scheduleResult.originalScaleUpStabilizationWindowSeconds != nil {
 		hpa.Spec.Behavior.ScaleUp.StabilizationWindowSeconds = scheduleResult.originalScaleUpStabilizationWindowSeconds
 	}
+
+	// Remove ScaleUp policy we added for prescale by searching for the policy with PeriodSeconds = 5 and percent = scheduleResult.bestMissedSchedule.Percent
+	for i, policy := range hpa.Spec.Behavior.ScaleUp.Policies {
+		if policy.PeriodSeconds == 5 && policy.Value == scheduleResult.bestMissedSchedule.Percent {
+			hpa.Spec.Behavior.ScaleUp.Policies = append(hpa.Spec.Behavior.ScaleUp.Policies[:i], hpa.Spec.Behavior.ScaleUp.Policies[i+1:]...)
+			break
+		}
+	}
+
 	if err := r.Update(ctx, hpa); err != nil {
 		log.Error(err, "failed to update hpa for revert")
 		r.Recorder.Event(prescaler, corev1.EventTypeWarning, "FailedUpdateHPA", err.Error())