fix: find spec.replicas workload

pkg/util/controllerfinder/controller_finder.go

@@ -439,13 +439,20 @@ func (r *ControllerFinder) getPodStatefulSetLike(ref ControllerReference, namesp
 			UID:         workload.GetUID(),
 		},
 	}
-	obj := workload.UnstructuredContent()
-	if val, found, err := unstructured.NestedInt64(obj, "spec.replicas"); err == nil && found {
-		scaleSelector.Scale = int32(val)
+	if val, err := getSpecReplicas(workload); err == nil {
+		scaleSelector.Scale = val
 	}
 	return scaleSelector, nil
 }
 
+func getSpecReplicas(workload *unstructured.Unstructured) (int32, error) {
+	obj := workload.UnstructuredContent()
+	if val, found, err := unstructured.NestedInt64(obj, "spec", "replicas"); err == nil && found {
+		return int32(val), nil
+	}
+	return 0, nil
+}
+
 func (r *ControllerFinder) getScaleController(ref ControllerReference, namespace string) (*ScaleAndSelector, error) {
 	if isValidGroupVersionKind(ref.APIVersion, ref.Kind) {
 		return nil, nil

pkg/util/controllerfinder/controller_finder_test.go

@@ -0,0 +1,84 @@
+/*
+Copyright 2021 The Kruise 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 controllerfinder
+
+import (
+	"testing"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+)
+
+func Test_getSpecReplicas(t *testing.T) {
+	type args struct {
+		workload *unstructured.Unstructured
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    int32
+		wantErr bool
+	}{
+		{
+			name: "replicas exist",
+			args: args{
+				workload: &unstructured.Unstructured{
+					Object: map[string]interface{}{
+						"spec": map[string]interface{}{
+							"replicas": int64(3),
+						},
+					},
+				},
+			},
+			want:    3,
+			wantErr: false,
+		},
+		{
+			name: "replicas do not exist",
+			args: args{
+				workload: &unstructured.Unstructured{
+					Object: map[string]interface{}{
+						"spec": map[string]interface{}{},
+					},
+				},
+			},
+			want:    0,
+			wantErr: false,
+		},
+		{
+			name: "spec does not exist",
+			args: args{
+				workload: &unstructured.Unstructured{
+					Object: map[string]interface{}{},
+				},
+			},
+			want:    0,
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := getSpecReplicas(tt.args.workload)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("getSpecReplicas() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("getSpecReplicas() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}