Fix: UpdateStrategy.RollingUpdate.Partition is lost when UpdateStrategy.Type is not set

pkg/apis/apps/v1/defaults_test.go

@@ -173,6 +173,7 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 	defaultLabels := map[string]string{"foo": "bar"}
 	var defaultPartition int32 = 0
 	var defaultReplicas int32 = 1
+	var notTheDefaultPartition int32 = 42
 
 	period := int64(v1.DefaultTerminationGracePeriodSeconds)
 	defaultTemplate := v1.PodTemplateSpec{
@@ -265,6 +266,35 @@ func TestSetDefaultStatefulSet(t *testing.T) {
 				},
 			},
 		},
+		{ // UpdateStrategy.RollingUpdate.Partition is not lost when UpdateStrategy.Type is not set
+			original: &appsv1.StatefulSet{
+				Spec: appsv1.StatefulSetSpec{
+					Template: defaultTemplate,
+					UpdateStrategy: appsv1.StatefulSetUpdateStrategy{
+						RollingUpdate: &appsv1.RollingUpdateStatefulSetStrategy{
+							Partition: &notTheDefaultPartition,
+						},
+					},
+				},
+			},
+			expected: &appsv1.StatefulSet{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: defaultLabels,
+				},
+				Spec: appsv1.StatefulSetSpec{
+					Replicas:            &defaultReplicas,
+					Template:            defaultTemplate,
+					PodManagementPolicy: appsv1.OrderedReadyPodManagement,
+					UpdateStrategy: appsv1.StatefulSetUpdateStrategy{
+						Type: appsv1.RollingUpdateStatefulSetStrategyType,
+						RollingUpdate: &appsv1.RollingUpdateStatefulSetStrategy{
+							Partition: &notTheDefaultPartition,
+						},
+					},
+					RevisionHistoryLimit: utilpointer.Int32Ptr(10),
+				},
+			},
+		},
 	}
 
 	for i, test := range tests {