fix: Check if MaxReplicaCount is nil before access to it

Signed-off-by: Zbynek Roubalik <zroubalik@gmail.com>

CHANGELOG.md

@@ -62,6 +62,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 ### Fixes
 
 - **Admission Webhooks**: Allow to remove the finalizer even if the ScaledObject isn't valid ([#4396](https://github.com/kedacore/keda/issue/4396))
+- **ScaledJob**: Check if MaxReplicaCount is nil before access to it ([#4568]https://github.com/kedacore/keda/issues/4568)
 - **AWS SQS Scaler**: Respect `scaleOnInFlight` value ([#4276](https://github.com/kedacore/keda/issue/4276))
 - **Azure Pipelines**: Fix for disallowing `$top` on query when using `meta.parentID` method ([#4397])
 - **Azure Pipelines**: Respect all required demands ([#4404](https://github.com/kedacore/keda/issues/4404))

apis/keda/v1alpha1/scaledjob_types.go

@@ -21,6 +21,11 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+const (
+	defaultScaledJobMaxReplicaCount = 100
+	defaultScaledJobMinReplicaCount = 0
+)
+
 // +genclient
 // +kubebuilder:object:root=true
 // +kubebuilder:subresource:status
@@ -114,19 +119,23 @@ func init() {
 // MaxReplicaCount returns MaxReplicaCount
 func (s ScaledJob) MaxReplicaCount() int64 {
 	if s.Spec.MaxReplicaCount != nil {
+		if s.Spec.MinReplicaCount != nil && *s.Spec.MinReplicaCount > *s.Spec.MaxReplicaCount {
+			return int64(*s.Spec.MaxReplicaCount)
+		}
 		return int64(*s.Spec.MaxReplicaCount) - s.MinReplicaCount()
 	}
 
-	return 100
+	return defaultScaledJobMaxReplicaCount
 }
 
 // MinReplicaCount returns MinReplicaCount
 func (s ScaledJob) MinReplicaCount() int64 {
 	if s.Spec.MinReplicaCount != nil {
-		if *s.Spec.MinReplicaCount > *s.Spec.MaxReplicaCount {
+		if s.Spec.MaxReplicaCount != nil &&
+			*s.Spec.MinReplicaCount > *s.Spec.MaxReplicaCount {
 			return int64(*s.Spec.MaxReplicaCount)
 		}
 		return int64(*s.Spec.MinReplicaCount)
 	}
-	return 0
+	return defaultScaledJobMinReplicaCount
 }

apis/keda/v1alpha1/scaledjob_types_test.go

@@ -0,0 +1,98 @@
+/*
+Copyright 2023 The KEDA Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	"testing"
+)
+
+func TestScaledJob(t *testing.T) {
+	tests := []struct {
+		name        string
+		expectedMax int64
+		expectedMin int64
+		maxReplicas *int32
+		minReplicas *int32
+	}{
+		{
+			name:        "MaxReplicaCount is set to 10 and MinReplicaCount is set to 0",
+			expectedMax: 10,
+			expectedMin: 0,
+			maxReplicas: int32Ptr(10),
+			minReplicas: int32Ptr(0),
+		},
+		{
+			name:        "MaxReplicaCount is set to 10 and MinReplicaCount is nil",
+			expectedMax: 10,
+			expectedMin: defaultScaledJobMinReplicaCount,
+			maxReplicas: int32Ptr(10),
+			minReplicas: nil,
+		},
+		{
+			name:        "MaxReplicaCount is set to 10 and MinReplicaCount is set to 1",
+			expectedMax: 9,
+			expectedMin: 1,
+			maxReplicas: int32Ptr(10),
+			minReplicas: int32Ptr(1),
+		},
+		{
+			name:        "MaxReplicaCount is nil and MinReplicaCount is set to 1",
+			expectedMax: defaultScaledJobMaxReplicaCount,
+			expectedMin: 1,
+			maxReplicas: nil,
+			minReplicas: int32Ptr(1),
+		},
+		{
+			name:        "MaxReplicaCount is nil and MinReplicaCount nil",
+			expectedMax: defaultScaledJobMaxReplicaCount,
+			expectedMin: defaultScaledJobMinReplicaCount,
+			maxReplicas: nil,
+			minReplicas: nil,
+		},
+		{
+			name:        "MaxReplicaCount is set to 1 and MinReplicaCount is set to 10",
+			expectedMax: 1,
+			expectedMin: 1,
+			maxReplicas: int32Ptr(1),
+			minReplicas: int32Ptr(10),
+		},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			scaledJob := &ScaledJob{
+				Spec: ScaledJobSpec{
+					MaxReplicaCount: test.maxReplicas,
+					MinReplicaCount: test.minReplicas,
+				},
+			}
+
+			if scaledJob.MaxReplicaCount() != test.expectedMax {
+				t.Errorf("MaxReplicaCount()=%d, expected %d", scaledJob.MaxReplicaCount(), test.expectedMax)
+			}
+
+			if scaledJob.MinReplicaCount() != test.expectedMin {
+				t.Errorf("MinReplicaCount()=%d, expected %d", scaledJob.MinReplicaCount(), test.expectedMin)
+			}
+		})
+	}
+}
+
+func int32Ptr(i int32) *int32 {
+	return &i
+}