From c3c7ac3d77d9440d7fe0cf6b476f3fb23f082452 Mon Sep 17 00:00:00 2001
From: Stavros Kontopoulos <st.kontopoulos@gmail.com>
Date: Fri, 20 Sep 2024 15:06:55 +0300
Subject: [PATCH] fix target name

---
 .../autoscaling/hpa/resources/keda.go         | 24 +++++++++++++++++--
 .../autoscaling/hpa/resources/keda_test.go    |  5 ++++
 .../hpa/resources/scaled_object.go            |  1 -
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/pkg/reconciler/autoscaling/hpa/resources/keda.go b/pkg/reconciler/autoscaling/hpa/resources/keda.go
index 925ba501..c97463d6 100644
--- a/pkg/reconciler/autoscaling/hpa/resources/keda.go
+++ b/pkg/reconciler/autoscaling/hpa/resources/keda.go
@@ -50,6 +50,8 @@ const (
 	KedaAutoscalingAnnotationHPAScaleUpRules       = autoscaling.GroupName + "/hpa-scale-up-rules"
 	KedaAutoscalingAnnotationHPAScaleDownRules     = autoscaling.GroupName + "/hpa-scale-down-rules"
 	KedaAutoscaleAnnotationsScaledObjectOverride   = autoscaling.GroupName + "/scaled-object-override"
+
+	defaultCPUTarget = 70
 )
 
 // DesiredScaledObject creates an ScaledObject KEDA resource from a PA resource.
@@ -90,7 +92,7 @@ func DesiredScaledObject(ctx context.Context, pa *autoscalingv1alpha1.PodAutosca
 		sO.Spec.MinReplicaCount = ptr.Int32(1)
 	}
 
-	if target, ok := pa.Target(); ok {
+	if target, ok := resolveTarget(pa); ok {
 		mt, err := getMetricType(pa.Annotations, pa.Metric())
 		if err != nil {
 			return nil, err
@@ -151,6 +153,10 @@ func DesiredScaledObject(ctx context.Context, pa *autoscalingv1alpha1.PodAutosca
 
 	sO.Spec.Triggers = append(sO.Spec.Triggers, extraPrometheusTriggers...)
 
+	if len(sO.Spec.Triggers) == 0 {
+		return nil, fmt.Errorf("no triggers were specified, make sure a metric target is specified or extra triggers are added")
+	}
+
 	if window, hasWindow := pa.Window(); hasWindow {
 		windowSeconds := int32(window.Seconds())
 		sO.Spec.Advanced.HorizontalPodAutoscalerConfig.Behavior = &autoscalingv2.HorizontalPodAutoscalerBehavior{
@@ -188,6 +194,18 @@ func DesiredScaledObject(ctx context.Context, pa *autoscalingv1alpha1.PodAutosca
 	return &sO, nil
 }
 
+func resolveTarget(pa *autoscalingv1alpha1.PodAutoscaler) (float64, bool) {
+	if target, ok := pa.Target(); ok {
+		return target, true
+	}
+	// When user has not specified a target value, we default to 70% for CPU
+	// This improves the UX as Serving defaults to CPU if no metric is specified via an annotation.
+	if pa.Metric() == autoscaling.CPU {
+		return defaultCPUTarget, true
+	}
+	return 0, false
+}
+
 func getDefaultPrometheusTrigger(annotations map[string]string, address string, query string, threshold string, ns string, targetType autoscalingv2.MetricTargetType) (*v1alpha1.ScaleTriggers, error) {
 	var name string
 
@@ -303,7 +321,9 @@ func setScaledObjectDefaults(sO *v1alpha1.ScaledObject, max int32, pa *autoscali
 	if sO.Spec.ScaleTargetRef == nil {
 		sO.Spec.ScaleTargetRef = &v1alpha1.ScaleTarget{}
 	}
-	sO.Spec.ScaleTargetRef.Name = pa.Name + "-deployment"
+	sO.Spec.ScaleTargetRef.Name = pa.Spec.ScaleTargetRef.Name
+	sO.Spec.ScaleTargetRef.Kind = pa.Spec.ScaleTargetRef.Kind
+	sO.Spec.ScaleTargetRef.APIVersion = pa.Spec.ScaleTargetRef.APIVersion
 	if sO.Spec.Advanced == nil {
 		sO.Spec.Advanced = &v1alpha1.AdvancedConfig{}
 		sO.Spec.Advanced.HorizontalPodAutoscalerConfig = &v1alpha1.HorizontalPodAutoscalerConfig{}
diff --git a/pkg/reconciler/autoscaling/hpa/resources/keda_test.go b/pkg/reconciler/autoscaling/hpa/resources/keda_test.go
index 099108eb..7d89e064 100644
--- a/pkg/reconciler/autoscaling/hpa/resources/keda_test.go
+++ b/pkg/reconciler/autoscaling/hpa/resources/keda_test.go
@@ -319,6 +319,11 @@ func TestDesiredScaledObject(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			pa := helpers.PodAutoscaler(helpers.TestNamespace, helpers.TestRevision, WithHPAClass, helpers.WithAnnotations(tt.paAnnotations))
 			scaledObject, err := DesiredScaledObject(ctx, pa)
+			if tt.wantScaledObject != nil {
+				tt.wantScaledObject.Spec.ScaleTargetRef.Name = pa.Spec.ScaleTargetRef.Name
+				tt.wantScaledObject.Spec.ScaleTargetRef.Kind = pa.Spec.ScaleTargetRef.Kind
+				tt.wantScaledObject.Spec.ScaleTargetRef.APIVersion = pa.Spec.ScaleTargetRef.APIVersion
+			}
 			if (err != nil) != tt.wantErr {
 				t.Fatalf("Failed to create desiredScaledObject, error = %v, want: %v", err, tt.wantErr)
 			} else if err == nil {
diff --git a/pkg/reconciler/autoscaling/hpa/resources/scaled_object.go b/pkg/reconciler/autoscaling/hpa/resources/scaled_object.go
index d487691e..1bc5993c 100644
--- a/pkg/reconciler/autoscaling/hpa/resources/scaled_object.go
+++ b/pkg/reconciler/autoscaling/hpa/resources/scaled_object.go
@@ -32,7 +32,6 @@ func ScaledObject(namespace, name string, options ...ScaledObjectOption) *kedav1
 			Namespace: namespace,
 		},
 		Spec: kedav1alpha1.ScaledObjectSpec{
-			ScaleTargetRef: &kedav1alpha1.ScaleTarget{Name: name + "-deployment"},
 			Advanced: &kedav1alpha1.AdvancedConfig{
 				HorizontalPodAutoscalerConfig: &kedav1alpha1.HorizontalPodAutoscalerConfig{}},
 		},