Delete the cache entry when a ScaledObject is deleted

CHANGELOG.md

@@ -34,6 +34,7 @@
 - Azure EventHub Scaler: don't expose connection string in metricName ([#2404](https://github.com/kedacore/keda/pull/2404))
 - `keda-operator` Cluster Role: add `list` and `watch` access to service accounts ([#2406](https://github.com/kedacore/keda/pull/2406))|([#2410](https://github.com/kedacore/keda/pull/2410))
 - Kafka Scaler: concurrently query brokers for consumer and producer offsets ([#2405](https://github.com/kedacore/keda/pull/2405))
+- Delete the cache entry when a ScaledObject is deleted ([#2408](https://github.com/kedacore/keda/pull/2408))
 
 - TODO ([#XXX](https://github.com/kedacore/keda/pull/XXX))
 

apis/keda/v1alpha1/withtriggers_types.go

@@ -18,6 +18,7 @@ package v1alpha1
 
 import (
 	"fmt"
+	"strings"
 	"time"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -90,5 +91,5 @@ func (t *WithTriggers) GetPollingInterval() time.Duration {
 
 // GenerateIdenitifier returns identifier for the object in for "kind.namespace.name"
 func (t *WithTriggers) GenerateIdenitifier() string {
-	return fmt.Sprintf("%s.%s.%s", t.Kind, t.Namespace, t.Name)
+	return strings.ToLower(fmt.Sprintf("%s.%s.%s", t.Kind, t.Namespace, t.Name))
 }

controllers/keda/scaledobject_controller_test.go

@@ -292,6 +292,81 @@ var _ = Describe("ScaledObjectController", func() {
 			Expect(hpa.Spec.Metrics[0].External.Metric.Name).To(Equal("s0-cron-UTC-0xxxx-1xxxx"))
 		})
 
+		//https://github.com/kedacore/keda/issues/2407
+		It("cache is correctly recreated if SO is deleted and created", func() {
+			// Create the scaling target.
+			err := k8sClient.Create(context.Background(), generateDeployment("cache-regenerate"))
+			Expect(err).ToNot(HaveOccurred())
+
+			// Create the ScaledObject with one trigger.
+			so := &kedav1alpha1.ScaledObject{
+				ObjectMeta: metav1.ObjectMeta{Name: "cache-regenerate", Namespace: "default"},
+				Spec: kedav1alpha1.ScaledObjectSpec{
+					ScaleTargetRef: &kedav1alpha1.ScaleTarget{
+						Name: "cache-regenerate",
+					},
+					Triggers: []kedav1alpha1.ScaleTriggers{
+						{
+							Type: "cron",
+							Metadata: map[string]string{
+								"timezone":        "UTC",
+								"start":           "0 * * * *",
+								"end":             "1 * * * *",
+								"desiredReplicas": "1",
+							},
+						},
+					},
+				},
+			}
+			err = k8sClient.Create(context.Background(), so)
+			Expect(err).ToNot(HaveOccurred())
+
+			// Get and confirm the HPA.
+			hpa := &autoscalingv2beta2.HorizontalPodAutoscaler{}
+			Eventually(func() error {
+				return k8sClient.Get(context.Background(), types.NamespacedName{Name: "keda-hpa-cache-regenerate", Namespace: "default"}, hpa)
+			}).ShouldNot(HaveOccurred())
+			Expect(hpa.Spec.Metrics).To(HaveLen(1))
+			Expect(hpa.Spec.Metrics[0].External.Metric.Name).To(Equal("s0-cron-UTC-0xxxx-1xxxx"))
+
+			// Delete the ScaledObject
+			err = k8sClient.Delete(context.Background(), so)
+			Expect(err).ToNot(HaveOccurred())
+			time.Sleep(30 * time.Second)
+
+			// Create the same ScaledObject with a change in the trigger.
+			so = &kedav1alpha1.ScaledObject{
+				ObjectMeta: metav1.ObjectMeta{Name: "cache-regenerate", Namespace: "default"},
+				Spec: kedav1alpha1.ScaledObjectSpec{
+					ScaleTargetRef: &kedav1alpha1.ScaleTarget{
+						Name: "cache-regenerate",
+					},
+					Triggers: []kedav1alpha1.ScaleTriggers{
+						{
+							Type: "cron",
+							Metadata: map[string]string{
+								"timezone":        "CET",
+								"start":           "0 * * * *",
+								"end":             "1 * * * *",
+								"desiredReplicas": "1",
+							},
+						},
+					},
+				},
+			}
+			err = k8sClient.Create(context.Background(), so)
+			Expect(err).ToNot(HaveOccurred())
+			time.Sleep(30 * time.Second)
+
+			// Get and confirm the HPA.
+			hpa2 := &autoscalingv2beta2.HorizontalPodAutoscaler{}
+			Eventually(func() error {
+				return k8sClient.Get(context.Background(), types.NamespacedName{Name: "keda-hpa-cache-regenerate", Namespace: "default"}, hpa2)
+			}).ShouldNot(HaveOccurred())
+			Expect(hpa2.Spec.Metrics).To(HaveLen(1))
+			Expect(hpa2.Spec.Metrics[0].External.Metric.Name).To(Equal("s0-cron-CET-0xxxx-1xxxx"))
+		})
+
 		It("deploys ScaledObject and creates HPA, when IdleReplicaCount, MinReplicaCount and MaxReplicaCount is defined", func() {
 
 			deploymentName := "idleminmax"

go.mod

@@ -111,6 +111,7 @@ require (
 	github.com/go-openapi/jsonreference v0.19.5 // indirect
 	github.com/go-openapi/swag v0.19.15 // indirect
 	github.com/go-stack/stack v1.8.0 // indirect
+	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang-sql/civil v0.0.0-20190719163853-cb61b32ac6fe // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect

go.sum

@@ -362,6 +362,7 @@ github.com/go-sql-driver/mysql v1.6.0 h1:BCTh4TKNUYmOmMUcQ3IipzF5prigylS7XXjEkfC
 github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
+github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 h1:p104kn46Q8WdvHunIJ9dAyjPVtrBPhSr3KT2yUst43I=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
 github.com/go-test/deep v1.0.2 h1:onZX1rnHT3Wv6cqNgYyFOOlgVKJrksuCMCRvJStbMYw=
 github.com/go-test/deep v1.0.2/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=

pkg/scaling/scale_handler.go

@@ -126,6 +126,7 @@ func (h *scaleHandler) DeleteScalableObject(ctx context.Context, scalableObject
 			cancel()
 		}
 		h.scaleLoopContexts.Delete(key)
+		delete(h.scalerCaches, key)
 		h.recorder.Event(withTriggers, corev1.EventTypeNormal, eventreason.KEDAScalersStopped, "Stopped scalers watch")
 	} else {
 		h.logger.V(1).Info("ScaleObject was not found in controller cache", "key", key)
@@ -163,7 +164,7 @@ func (h *scaleHandler) GetScalersCache(ctx context.Context, scalableObject inter
 		return nil, err
 	}
 
-	key := strings.ToLower(fmt.Sprintf("%s.%s.%s", withTriggers.Kind, withTriggers.Name, withTriggers.Namespace))
+	key := withTriggers.GenerateIdenitifier()
 
 	h.lock.RLock()
 	if cache, ok := h.scalerCaches[key]; ok && cache.Generation == withTriggers.Generation {