Refactoring of pod autoscaler controller

pkg/controller/podautoscaler/horizontal.go

@@ -231,15 +231,33 @@ func (a *HorizontalController) reconcileAutoscaler(hpa extensions.HorizontalPodA
 			desiredReplicas = hpa.Spec.MaxReplicas
 		}
 	}
-	rescale := false
 
+	rescale := shouldScale(hpa, currentReplicas, desiredReplicas, timestamp)
+	if rescale {
+		scale.Spec.Replicas = desiredReplicas
+		_, err = a.scaleNamespacer.Scales(hpa.Namespace).Update(hpa.Spec.ScaleRef.Kind, scale)
+		if err != nil {
+			a.eventRecorder.Eventf(&hpa, api.EventTypeWarning, "FailedRescale", "New size: %d; error: %v", desiredReplicas, err.Error())
+			return fmt.Errorf("failed to rescale %s: %v", reference, err)
+		}
+		a.eventRecorder.Eventf(&hpa, api.EventTypeNormal, "SuccessfulRescale", "New size: %d", desiredReplicas)
+		glog.Infof("Successfull rescale of %s, old size: %d, new size: %d",
+			hpa.Name, currentReplicas, desiredReplicas)
+	} else {
+		desiredReplicas = currentReplicas
+	}
+
+	return a.updateStatus(hpa, currentReplicas, desiredReplicas, cpuCurrentUtilization, cmStatus, rescale)
+}
+
+func shouldScale(hpa extensions.HorizontalPodAutoscaler, currentReplicas, desiredReplicas int, timestamp time.Time) bool {
 	if desiredReplicas != currentReplicas {
 		// Going down only if the usageRatio dropped significantly below the target
 		// and there was no rescaling in the last downscaleForbiddenWindow.
 		if desiredReplicas < currentReplicas &&
 			(hpa.Status.LastScaleTime == nil ||
 				hpa.Status.LastScaleTime.Add(downscaleForbiddenWindow).Before(timestamp)) {
-			rescale = true
+			return true
 		}
 
 		// Going up only if the usage ratio increased significantly above the target
@@ -247,24 +265,13 @@ func (a *HorizontalController) reconcileAutoscaler(hpa extensions.HorizontalPodA
 		if desiredReplicas > currentReplicas &&
 			(hpa.Status.LastScaleTime == nil ||
 				hpa.Status.LastScaleTime.Add(upscaleForbiddenWindow).Before(timestamp)) {
-			rescale = true
+			return true
 		}
 	}
+	return false
+}
 
-	if rescale {
-		scale.Spec.Replicas = desiredReplicas
-		_, err = a.scaleNamespacer.Scales(hpa.Namespace).Update(hpa.Spec.ScaleRef.Kind, scale)
-		if err != nil {
-			a.eventRecorder.Eventf(&hpa, api.EventTypeWarning, "FailedRescale", "New size: %d; error: %v", desiredReplicas, err.Error())
-			return fmt.Errorf("failed to rescale %s: %v", reference, err)
-		}
-		a.eventRecorder.Eventf(&hpa, api.EventTypeNormal, "SuccessfulRescale", "New size: %d", desiredReplicas)
-		glog.Infof("Successfull rescale of %s, old size: %d, new size: %d",
-			hpa.Name, currentReplicas, desiredReplicas)
-	} else {
-		desiredReplicas = currentReplicas
-	}
-
+func (a *HorizontalController) updateStatus(hpa extensions.HorizontalPodAutoscaler, currentReplicas, desiredReplicas int, cpuCurrentUtilization *int, cmStatus string, rescale bool) error {
 	hpa.Status = extensions.HorizontalPodAutoscalerStatus{
 		CurrentReplicas:                 currentReplicas,
 		DesiredReplicas:                 desiredReplicas,
@@ -280,7 +287,7 @@ func (a *HorizontalController) reconcileAutoscaler(hpa extensions.HorizontalPodA
 		hpa.Status.LastScaleTime = &now
 	}
 
-	_, err = a.hpaNamespacer.HorizontalPodAutoscalers(hpa.Namespace).UpdateStatus(&hpa)
+	_, err := a.hpaNamespacer.HorizontalPodAutoscalers(hpa.Namespace).UpdateStatus(&hpa)
 	if err != nil {
 		a.eventRecorder.Event(&hpa, api.EventTypeWarning, "FailedUpdateStatus", err.Error())
 		return fmt.Errorf("failed to update status for %s: %v", hpa.Name, err)