Implements StatefulSet update

Implements history utilities for ControllerRevision in the controller/history package
StatefulSetStatus now has additional fields for consistency with DaemonSet and Deployment
StatefulSetStatus.Replicas now represents the current number of createdPods and StatefulSetStatus.ReadyReplicas is the current number of ready Pods

pkg/apis/apps/types.go

@@ -60,6 +60,54 @@ const (
 	ParallelPodManagement = "Parallel"
 )
 
+// StatefulSetUpdateStrategy indicates the strategy that the StatefulSet
+// controller will use to perform updates. It includes any additional parameters
+// necessary to perform the update for the indicated strategy.
+type StatefulSetUpdateStrategy struct {
+	// Type indicates the type of the StatefulSetUpdateStrategy.
+	Type StatefulSetUpdateStrategyType
+	// Partition is used to communicate the ordinal at which to partition
+	// the StatefulSet when Type is PartitionStatefulSetStrategyType. This
+	// value must be set when Type is PartitionStatefulSetStrategyType,
+	// and it must be nil otherwise.
+	Partition *PartitionStatefulSetStrategy
+}
+
+// StatefulSetUpdateStrategyType is a string enumeration type that enumerates
+// all possible update strategies for the StatefulSet controller.
+type StatefulSetUpdateStrategyType string
+
+const (
+	// PartitionStatefulSetStrategyType indicates that updates will only be
+	// applied to a partition of the StatefulSet. This is useful for canaries
+	// and phased roll outs. When a scale operation is performed with this
+	// strategy, new Pods will be created from the specification version indicated
+	// by the StatefulSet's currentRevision if there ordinal is less than the supplied
+	// Partition's ordinal. Otherwise, they will be created from the specification
+	// version indicated by the StatefulSet's updateRevision.
+	PartitionStatefulSetStrategyType StatefulSetUpdateStrategyType = "Partition"
+	// RollingUpdateStatefulSetStrategyType indicates that update will be
+	// applied to all Pods in the StatefulSet with respect to the StatefulSet
+	// ordering constraints. When a scale operation is performed with this
+	// strategy, new Pods will be created from the specification version indicated
+	// by the StatefulSet's updateRevision.
+	RollingUpdateStatefulSetStrategyType = "RollingUpdate"
+	// OnDeleteStatefulSetStrategyType triggers the legacy behavior. Version
+	// tracking and ordered rolling restarts are disabled. Pods are recreated
+	// from the StatefulSetSpec when they are manually deleted. When a scale
+	// operation is performed with this strategy,specification version indicated
+	// by the StatefulSet's currentRevision.
+	OnDeleteStatefulSetStrategyType = "OnDelete"
+)
+
+// PartitionStatefulSetStrategy contains the parameters used with the
+// PartitionStatefulSetStrategyType.
+type PartitionStatefulSetStrategy struct {
+	// Ordinal indicates the ordinal at which the StatefulSet should be
+	// partitioned.
+	Ordinal int32
+}
+
 // A StatefulSetSpec is the specification of a StatefulSet.
 type StatefulSetSpec struct {
 	// Replicas is the desired number of replicas of the given Template.
@@ -109,16 +157,47 @@ type StatefulSetSpec struct {
 	// all pods at once.
 	// +optional
 	PodManagementPolicy PodManagementPolicyType
+
+	// updateStrategy indicates the StatefulSetUpdateStrategy that will be
+	// employed to update Pods in the StatefulSet when a revision is made to
+	// Template.
+	UpdateStrategy StatefulSetUpdateStrategy
+
+	// revisionHistoryLimit is the maximum number of revisions that will
+	// be maintained in the StatefulSet's revision history. The revision history
+	// consists of all revisions not represented by a currently applied
+	// StatefulSetSpec version. The default value is 10.
+	RevisionHistoryLimit *int32
 }
 
 // StatefulSetStatus represents the current state of a StatefulSet.
 type StatefulSetStatus struct {
-	// most recent generation observed by this StatefulSet.
+	// observedGeneration is the most recent generation observed for this StatefulSet. It corresponds to the
+	// StatefulSet's generation, which is updated on mutation by the API Server.
 	// +optional
 	ObservedGeneration *int64
 
-	// Replicas is the number of actual replicas.
+	// replicas is the number of Pods created by the StatefulSet controller.
 	Replicas int32
+
+	// readyReplicas is the number of Pods created by the StatefulSet controller that have a Ready Condition.
+	ReadyReplicas int32
+
+	// currentReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version
+	// indicated by currentRevision.
+	CurrentReplicas int32
+
+	// updatedReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version
+	// indicated by updateRevision.
+	UpdatedReplicas int32
+
+	// currentRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the
+	// sequence [0,currentReplicas).
+	CurrentRevision string
+
+	// updateRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence
+	// [replicas-updatedReplicas,replicas)
+	UpdateRevision string
 }
 
 // StatefulSetList is a collection of StatefulSets.

pkg/apis/apps/v1beta1/conversion.go

@@ -37,6 +37,8 @@ func addConversionFuncs(scheme *runtime.Scheme) error {
 	err := scheme.AddConversionFuncs(
 		Convert_v1beta1_StatefulSetSpec_To_apps_StatefulSetSpec,
 		Convert_apps_StatefulSetSpec_To_v1beta1_StatefulSetSpec,
+		Convert_v1beta1_StatefulSetUpdateStrategy_To_apps_StatefulSetUpdateStrategy,
+		Convert_apps_StatefulSetUpdateStrategy_To_v1beta1_StatefulSetUpdateStrategy,
 		// extensions
 		// TODO: below conversions should be dropped in favor of auto-generated
 		// ones, see https://github.com/kubernetes/kubernetextensionsssues/39865
@@ -109,6 +111,15 @@ func Convert_v1beta1_StatefulSetSpec_To_apps_StatefulSetSpec(in *StatefulSetSpec
 	} else {
 		out.VolumeClaimTemplates = nil
 	}
+	if err := Convert_v1beta1_StatefulSetUpdateStrategy_To_apps_StatefulSetUpdateStrategy(&in.UpdateStrategy, &out.UpdateStrategy, s); err != nil {
+		return err
+	}
+	if in.RevisionHistoryLimit != nil {
+		out.RevisionHistoryLimit = new(int32)
+		*out.RevisionHistoryLimit = *in.RevisionHistoryLimit
+	} else {
+		out.RevisionHistoryLimit = nil
+	}
 	out.ServiceName = in.ServiceName
 	out.PodManagementPolicy = apps.PodManagementPolicyType(in.PodManagementPolicy)
 	return nil
@@ -140,8 +151,39 @@ func Convert_apps_StatefulSetSpec_To_v1beta1_StatefulSetSpec(in *apps.StatefulSe
 	} else {
 		out.VolumeClaimTemplates = nil
 	}
+	if in.RevisionHistoryLimit != nil {
+		out.RevisionHistoryLimit = new(int32)
+		*out.RevisionHistoryLimit = *in.RevisionHistoryLimit
+	} else {
+		out.RevisionHistoryLimit = nil
+	}
 	out.ServiceName = in.ServiceName
 	out.PodManagementPolicy = PodManagementPolicyType(in.PodManagementPolicy)
+	if err := Convert_apps_StatefulSetUpdateStrategy_To_v1beta1_StatefulSetUpdateStrategy(&in.UpdateStrategy, &out.UpdateStrategy, s); err != nil {
+		return err
+	}
+	return nil
+}
+
+func Convert_v1beta1_StatefulSetUpdateStrategy_To_apps_StatefulSetUpdateStrategy(in *StatefulSetUpdateStrategy, out *apps.StatefulSetUpdateStrategy, s conversion.Scope) error {
+	out.Type = apps.StatefulSetUpdateStrategyType(in.Type)
+	if in.Partition != nil {
+		out.Partition = new(apps.PartitionStatefulSetStrategy)
+		out.Partition.Ordinal = in.Partition.Ordinal
+	} else {
+		out.Partition = nil
+	}
+	return nil
+}
+
+func Convert_apps_StatefulSetUpdateStrategy_To_v1beta1_StatefulSetUpdateStrategy(in *apps.StatefulSetUpdateStrategy, out *StatefulSetUpdateStrategy, s conversion.Scope) error {
+	out.Type = StatefulSetUpdateStrategyType(in.Type)
+	if in.Partition != nil {
+		out.Partition = new(PartitionStatefulSetStrategy)
+		out.Partition.Ordinal = in.Partition.Ordinal
+	} else {
+		out.Partition = nil
+	}
 	return nil
 }
 

pkg/apis/apps/v1beta1/defaults.go

@@ -30,6 +30,10 @@ func SetDefaults_StatefulSet(obj *StatefulSet) {
 	if len(obj.Spec.PodManagementPolicy) == 0 {
 		obj.Spec.PodManagementPolicy = OrderedReadyPodManagement
 	}
+
+	if obj.Spec.UpdateStrategy.Type == "" {
+		obj.Spec.UpdateStrategy.Type = OnDeleteStatefulSetStrategyType
+	}
 	labels := obj.Spec.Template.Labels
 	if labels != nil {
 		if obj.Spec.Selector == nil {
@@ -45,6 +49,11 @@ func SetDefaults_StatefulSet(obj *StatefulSet) {
 		obj.Spec.Replicas = new(int32)
 		*obj.Spec.Replicas = 1
 	}
+	if obj.Spec.RevisionHistoryLimit == nil {
+		obj.Spec.RevisionHistoryLimit = new(int32)
+		*obj.Spec.RevisionHistoryLimit = 10
+	}
+
 }
 
 // SetDefaults_Deployment sets additional defaults compared to its counterpart

pkg/apis/apps/v1beta1/types.go

@@ -26,6 +26,7 @@ import (
 const (
 	// StatefulSetInitAnnotation if present, and set to false, indicates that a Pod's readiness should be ignored.
 	StatefulSetInitAnnotation = "pod.alpha.kubernetes.io/initialized"
+	StatefulSetRevisionLabel  = "statefulset.beta.kubernetes.io/revision"
 )
 
 // ScaleSpec describes the attributes of a scale subresource
@@ -111,6 +112,54 @@ const (
 	ParallelPodManagement = "Parallel"
 )
 
+// StatefulSetUpdateStrategy indicates the strategy that the StatefulSet
+// controller will use to perform updates. It includes any additional parameters
+// necessary to perform the update for the indicated strategy.
+type StatefulSetUpdateStrategy struct {
+	// Type indicates the type of the StatefulSetUpdateStrategy.
+	Type StatefulSetUpdateStrategyType `json:"type,omitempty" protobuf:"bytes,1,opt,name=type,casttype=StatefulSetStrategyType"`
+	// Partition is used to communicate the ordinal at which to partition
+	// the StatefulSet when Type is PartitionStatefulSetStrategyType. This
+	// value must be set when Type is PartitionStatefulSetStrategyType,
+	// and it must be nil otherwise.
+	Partition *PartitionStatefulSetStrategy `json:"partition,omitempty" protobuf:"bytes,2,opt,name=partition"`
+}
+
+// StatefulSetUpdateStrategyType is a string enumeration type that enumerates
+// all possible update strategies for the StatefulSet controller.
+type StatefulSetUpdateStrategyType string
+
+const (
+	// PartitionStatefulSetStrategyType indicates that updates will only be
+	// applied to a partition of the StatefulSet. This is useful for canaries
+	// and phased roll outs. When a scale operation is performed with this
+	// strategy, new Pods will be created from the specification version indicated
+	// by the StatefulSet's currentRevision if there ordinal is less than the supplied
+	// Partition's ordinal. Otherwise, they will be created from the specification
+	// version indicated by the StatefulSet's updateRevision.
+	PartitionStatefulSetStrategyType StatefulSetUpdateStrategyType = "Partition"
+	// RollingUpdateStatefulSetStrategyType indicates that update will be
+	// applied to all Pods in the StatefulSet with respect to the StatefulSet
+	// ordering constraints. When a scale operation is performed with this
+	// strategy, new Pods will be created from the specification version indicated
+	// by the StatefulSet's updateRevision.
+	RollingUpdateStatefulSetStrategyType = "RollingUpdate"
+	// OnDeleteStatefulSetStrategyType triggers the legacy behavior. Version
+	// tracking and ordered rolling restarts are disabled. Pods are recreated
+	// from the StatefulSetSpec when they are manually deleted. When a scale
+	// operation is performed with this strategy,specification version indicated
+	// by the StatefulSet's currentRevision.
+	OnDeleteStatefulSetStrategyType = "OnDelete"
+)
+
+// PartitionStatefulSetStrategy contains the parameters used with the
+// PartitionStatefulSetStrategyType.
+type PartitionStatefulSetStrategy struct {
+	// Ordinal indicates the ordinal at which the StatefulSet should be
+	// partitioned.
+	Ordinal int32 `json:"ordinal" protobuf:"varint,1,opt,name=ordinal"`
+}
+
 // A StatefulSetSpec is the specification of a StatefulSet.
 type StatefulSetSpec struct {
 	// replicas is the desired number of replicas of the given Template.
@@ -160,16 +209,47 @@ type StatefulSetSpec struct {
 	// all pods at once.
 	// +optional
 	PodManagementPolicy PodManagementPolicyType `json:"podManagementPolicy,omitempty" protobuf:"bytes,6,opt,name=podManagementPolicy,casttype=PodManagementPolicyType"`
+
+	// updateStrategy indicates the StatefulSetUpdateStrategy that will be
+	// employed to update Pods in the StatefulSet when a revision is made to
+	// Template.
+	UpdateStrategy StatefulSetUpdateStrategy `json:"updateStrategy,omitempty" protobuf:"bytes,7,opt,name=updateStrategy"`
+
+	// revisionHistoryLimit is the maximum number of revisions that will
+	// be maintained in the StatefulSet's revision history. The revision history
+	// consists of all revisions not represented by a currently applied
+	// StatefulSetSpec version. The default value is 10.
+	RevisionHistoryLimit *int32 `json:"revisionHistoryLimit,omitempty" protobuf:"varint,8,opt,name=revisionHistoryLimit"`
 }
 
 // StatefulSetStatus represents the current state of a StatefulSet.
 type StatefulSetStatus struct {
-	// observedGeneration is the most recent generation observed by this StatefulSet.
+	// observedGeneration is the most recent generation observed for this StatefulSet. It corresponds to the
+	// StatefulSet's generation, which is updated on mutation by the API Server.
 	// +optional
 	ObservedGeneration *int64 `json:"observedGeneration,omitempty" protobuf:"varint,1,opt,name=observedGeneration"`
 
-	// replicas is the number of actual replicas.
+	// replicas is the number of Pods created by the StatefulSet controller.
 	Replicas int32 `json:"replicas" protobuf:"varint,2,opt,name=replicas"`
+
+	// readyReplicas is the number of Pods created by the StatefulSet controller that have a Ready Condition.
+	ReadyReplicas int32 `json:"readyReplicas,omitempty" protobuf:"varint,3,opt,name=readyReplicas"`
+
+	// currentReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version
+	// indicated by currentRevision.
+	CurrentReplicas int32 `json:"currentReplicas,omitempty" protobuf:"varint,4,opt,name=currentReplicas"`
+
+	// updatedReplicas is the number of Pods created by the StatefulSet controller from the StatefulSet version
+	// indicated by updateRevision.
+	UpdatedReplicas int32 `json:"updatedReplicas,omitempty" protobuf:"varint,5,opt,name=updatedReplicas"`
+
+	// currentRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the
+	// sequence [0,currentReplicas).
+	CurrentRevision string `json:"currentRevision,omitempty" protobuf:"bytes,6,opt,name=currentRevision"`
+
+	// updateRevision, if not empty, indicates the version of the StatefulSet used to generate Pods in the sequence
+	// [replicas-updatedReplicas,replicas)
+	UpdateRevision string `json:"updateRevision,omitempty" protobuf:"bytes,7,opt,name=updateRevision"`
 }
 
 // StatefulSetList is a collection of StatefulSets.

pkg/apis/apps/validation/validation.go

@@ -75,6 +75,40 @@ func ValidateStatefulSetSpec(spec *apps.StatefulSetSpec, fldPath *field.Path) fi
 		allErrs = append(allErrs, field.Invalid(fldPath.Child("podManagementPolicy"), spec.PodManagementPolicy, fmt.Sprintf("must be '%s' or '%s'", apps.OrderedReadyPodManagement, apps.ParallelPodManagement)))
 	}
 
+	switch spec.UpdateStrategy.Type {
+	case "":
+		allErrs = append(allErrs, field.Required(fldPath.Child("updateStrategy"), ""))
+	case apps.OnDeleteStatefulSetStrategyType, apps.RollingUpdateStatefulSetStrategyType:
+		if spec.UpdateStrategy.Partition != nil {
+			allErrs = append(
+				allErrs,
+				field.Invalid(
+					fldPath.Child("updateStrategy").Child("partition"),
+					spec.UpdateStrategy.Partition.Ordinal,
+					fmt.Sprintf("only allowed for updateStrategy '%s'", apps.PartitionStatefulSetStrategyType)))
+		}
+	case apps.PartitionStatefulSetStrategyType:
+		if spec.UpdateStrategy.Partition == nil {
+			allErrs = append(
+				allErrs,
+				field.Required(
+					fldPath.Child("updateStrategy").Child("partition"),
+					fmt.Sprintf("required for updateStrategy '%s'", apps.PartitionStatefulSetStrategyType)))
+			break
+		}
+		allErrs = append(allErrs,
+			apivalidation.ValidateNonnegativeField(
+				int64(spec.UpdateStrategy.Partition.Ordinal),
+				fldPath.Child("updateStrategy").Child("partition").Child("ordinal"))...)
+	default:
+		allErrs = append(allErrs,
+			field.Invalid(fldPath.Child("updateStrategy"), spec.UpdateStrategy,
+				fmt.Sprintf("must be '%s', '%s', or '%s'",
+					apps.RollingUpdateStatefulSetStrategyType,
+					apps.OnDeleteStatefulSetStrategyType,
+					apps.PartitionStatefulSetStrategyType)))
+	}
+
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(spec.Replicas), fldPath.Child("replicas"))...)
 	if spec.Selector == nil {
 		allErrs = append(allErrs, field.Required(fldPath.Child("selector"), ""))
@@ -113,20 +147,21 @@ func ValidateStatefulSet(statefulSet *apps.StatefulSet) field.ErrorList {
 func ValidateStatefulSetUpdate(statefulSet, oldStatefulSet *apps.StatefulSet) field.ErrorList {
 	allErrs := apivalidation.ValidateObjectMetaUpdate(&statefulSet.ObjectMeta, &oldStatefulSet.ObjectMeta, field.NewPath("metadata"))
 
-	// TODO: For now we're taking the safe route and disallowing all updates to
-	// spec except for Replicas, for scaling, and Template.Spec.containers.image
-	// for rolling-update. Enable others on a case by case basis.
 	restoreReplicas := statefulSet.Spec.Replicas
 	statefulSet.Spec.Replicas = oldStatefulSet.Spec.Replicas
 
-	restoreContainers := statefulSet.Spec.Template.Spec.Containers
-	statefulSet.Spec.Template.Spec.Containers = oldStatefulSet.Spec.Template.Spec.Containers
+	restoreTemplate := statefulSet.Spec.Template
+	statefulSet.Spec.Template = oldStatefulSet.Spec.Template
+
+	restoreStrategy := statefulSet.Spec.UpdateStrategy
+	statefulSet.Spec.UpdateStrategy = oldStatefulSet.Spec.UpdateStrategy
 
 	if !reflect.DeepEqual(statefulSet.Spec, oldStatefulSet.Spec) {
-		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "updates to statefulset spec for fields other than 'replicas' and 'containers' are forbidden."))
+		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "updates to statefulset spec for fields other than 'replicas', 'template', and 'updateStrategy' are forbidden."))
 	}
 	statefulSet.Spec.Replicas = restoreReplicas
-	statefulSet.Spec.Template.Spec.Containers = restoreContainers
+	statefulSet.Spec.Template = restoreTemplate
+	statefulSet.Spec.UpdateStrategy = restoreStrategy
 
 	allErrs = append(allErrs, apivalidation.ValidateNonnegativeField(int64(statefulSet.Spec.Replicas), field.NewPath("spec", "replicas"))...)
 	containerErrs, _ := apivalidation.ValidateContainerUpdates(statefulSet.Spec.Template.Spec.Containers, oldStatefulSet.Spec.Template.Spec.Containers, field.NewPath("spec").Child("template").Child("containers"))

pkg/apis/apps/validation/validation_test.go

@@ -59,6 +59,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		{
@@ -67,6 +68,39 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
+			},
+		},
+		{
+			ObjectMeta: metav1.ObjectMeta{Name: "abc-123", Namespace: metav1.NamespaceDefault},
+			Spec: apps.StatefulSetSpec{
+				PodManagementPolicy: apps.ParallelPodManagement,
+				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
+			},
+		},
+		{
+			ObjectMeta: metav1.ObjectMeta{Name: "abc-123", Namespace: metav1.NamespaceDefault},
+			Spec: apps.StatefulSetSpec{
+				PodManagementPolicy: apps.OrderedReadyPodManagement,
+				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.OnDeleteStatefulSetStrategyType},
+			},
+		},
+		{
+			ObjectMeta: metav1.ObjectMeta{Name: "abc-123", Namespace: metav1.NamespaceDefault},
+			Spec: apps.StatefulSetSpec{
+				PodManagementPolicy: apps.OrderedReadyPodManagement,
+				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				Template:            validPodTemplate.Template,
+				Replicas:            3,
+				UpdateStrategy: apps.StatefulSetUpdateStrategy{
+					Type: apps.PartitionStatefulSetStrategyType,
+					Partition: func() *apps.PartitionStatefulSetStrategy {
+						return &apps.PartitionStatefulSetStrategy{Ordinal: 2}
+					}()},
 			},
 		},
 	}
@@ -83,6 +117,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"missing-namespace": {
@@ -91,6 +126,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"empty selector": {
@@ -98,6 +134,7 @@ func TestValidateStatefulSet(t *testing.T) {
 			Spec: apps.StatefulSetSpec{
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"selector_doesnt_match": {
@@ -106,6 +143,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"invalid manifest": {
@@ -113,6 +151,7 @@ func TestValidateStatefulSet(t *testing.T) {
 			Spec: apps.StatefulSetSpec{
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"negative_replicas": {
@@ -121,6 +160,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Replicas:            -1,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"invalid_label": {
@@ -135,6 +175,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"invalid_label 2": {
@@ -148,6 +189,7 @@ func TestValidateStatefulSet(t *testing.T) {
 			Spec: apps.StatefulSetSpec{
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Template:            invalidPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"invalid_annotation": {
@@ -162,6 +204,7 @@ func TestValidateStatefulSet(t *testing.T) {
 				PodManagementPolicy: apps.OrderedReadyPodManagement,
 				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 				Template:            validPodTemplate.Template,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"invalid restart policy 1": {
@@ -182,6 +225,7 @@ func TestValidateStatefulSet(t *testing.T) {
 						Labels: validLabels,
 					},
 				},
+				UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 			},
 		},
 		"invalid restart policy 2": {
@@ -202,6 +246,42 @@ func TestValidateStatefulSet(t *testing.T) {
 						Labels: validLabels,
 					},
 				},
+				UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
+			},
+		},
+		"invalid udpate strategy": {
+			ObjectMeta: metav1.ObjectMeta{Name: "abc-123", Namespace: metav1.NamespaceDefault},
+			Spec: apps.StatefulSetSpec{
+				PodManagementPolicy: apps.OrderedReadyPodManagement,
+				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				Template:            validPodTemplate.Template,
+				Replicas:            3,
+				UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: "foo"},
+			},
+		},
+		"partitioned rolling update": {
+			ObjectMeta: metav1.ObjectMeta{Name: "abc-123", Namespace: metav1.NamespaceDefault},
+			Spec: apps.StatefulSetSpec{
+				PodManagementPolicy: apps.OrderedReadyPodManagement,
+				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				Template:            validPodTemplate.Template,
+				Replicas:            3,
+				UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType,
+					Partition: func() *apps.PartitionStatefulSetStrategy {
+						return &apps.PartitionStatefulSetStrategy{Ordinal: 2}
+					}()},
+			},
+		},
+		"empty partition": {
+			ObjectMeta: metav1.ObjectMeta{Name: "abc-123", Namespace: metav1.NamespaceDefault},
+			Spec: apps.StatefulSetSpec{
+				PodManagementPolicy: apps.OrderedReadyPodManagement,
+				Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
+				Template:            validPodTemplate.Template,
+				Replicas:            3,
+				UpdateStrategy: apps.StatefulSetUpdateStrategy{
+					Type:      apps.PartitionStatefulSetStrategyType,
+					Partition: nil},
 			},
 		},
 	}
@@ -222,7 +302,10 @@ func TestValidateStatefulSet(t *testing.T) {
 				field != "spec.template.labels" &&
 				field != "metadata.annotations" &&
 				field != "metadata.labels" &&
-				field != "status.replicas" {
+				field != "status.replicas" &&
+				field != "spec.updateStrategy" &&
+				field != "spec.updateStrategy.partition" &&
+				field != "spec.updateStrategy.partition.ordinal" {
 				t.Errorf("%s: missing prefix for: %v", k, errs[i])
 			}
 		}
@@ -280,6 +363,7 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					PodManagementPolicy: apps.OrderedReadyPodManagement,
 					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 					Template:            validPodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 			update: apps.StatefulSet{
@@ -289,6 +373,7 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					Replicas:            3,
 					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 					Template:            validPodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},
@@ -305,8 +390,9 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 			old: apps.StatefulSet{
 				ObjectMeta: metav1.ObjectMeta{Name: "", Namespace: metav1.NamespaceDefault},
 				Spec: apps.StatefulSetSpec{
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: validPodTemplate.Template,
+					Selector:       &metav1.LabelSelector{MatchLabels: validLabels},
+					Template:       validPodTemplate.Template,
+					UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 			update: apps.StatefulSet{
@@ -316,6 +402,7 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					Replicas:            2,
 					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 					Template:            readWriteVolumePodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},
@@ -323,16 +410,18 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 			old: apps.StatefulSet{
 				ObjectMeta: metav1.ObjectMeta{Name: "abc", Namespace: metav1.NamespaceDefault},
 				Spec: apps.StatefulSetSpec{
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: validPodTemplate.Template,
+					Selector:       &metav1.LabelSelector{MatchLabels: validLabels},
+					Template:       validPodTemplate.Template,
+					UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 			update: apps.StatefulSet{
 				ObjectMeta: metav1.ObjectMeta{Name: "abc", Namespace: metav1.NamespaceDefault},
 				Spec: apps.StatefulSetSpec{
-					Replicas: 3,
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: validPodTemplate.Template,
+					Replicas:       3,
+					Selector:       &metav1.LabelSelector{MatchLabels: validLabels},
+					Template:       validPodTemplate.Template,
+					UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},
@@ -340,8 +429,9 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 			old: apps.StatefulSet{
 				ObjectMeta: metav1.ObjectMeta{Name: "abc", Namespace: metav1.NamespaceDefault},
 				Spec: apps.StatefulSetSpec{
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: validPodTemplate.Template,
+					Selector:       &metav1.LabelSelector{MatchLabels: validLabels},
+					Template:       validPodTemplate.Template,
+					UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 			update: apps.StatefulSet{
@@ -351,24 +441,7 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					Replicas:            3,
 					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 					Template:            validPodTemplate.Template,
-				},
-			},
-		},
-		"updates to a field other than spec.Replicas": {
-			old: apps.StatefulSet{
-				ObjectMeta: metav1.ObjectMeta{Name: "abc", Namespace: metav1.NamespaceDefault},
-				Spec: apps.StatefulSetSpec{
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: validPodTemplate.Template,
-				},
-			},
-			update: apps.StatefulSet{
-				ObjectMeta: metav1.ObjectMeta{Name: "abc", Namespace: metav1.NamespaceDefault},
-				Spec: apps.StatefulSetSpec{
-					PodManagementPolicy: apps.OrderedReadyPodManagement,
-					Replicas:            1,
-					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
-					Template:            readWriteVolumePodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},
@@ -376,8 +449,9 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 			old: apps.StatefulSet{
 				ObjectMeta: metav1.ObjectMeta{Name: "", Namespace: metav1.NamespaceDefault},
 				Spec: apps.StatefulSetSpec{
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: validPodTemplate.Template,
+					Selector:       &metav1.LabelSelector{MatchLabels: validLabels},
+					Template:       validPodTemplate.Template,
+					UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 			update: apps.StatefulSet{
@@ -387,6 +461,7 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					Replicas:            2,
 					Selector:            &metav1.LabelSelector{MatchLabels: invalidLabels},
 					Template:            validPodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},
@@ -397,14 +472,16 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					PodManagementPolicy: apps.OrderedReadyPodManagement,
 					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 					Template:            validPodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 			update: apps.StatefulSet{
 				ObjectMeta: metav1.ObjectMeta{Name: "abc", Namespace: metav1.NamespaceDefault},
 				Spec: apps.StatefulSetSpec{
-					Replicas: 2,
-					Selector: &metav1.LabelSelector{MatchLabels: validLabels},
-					Template: invalidPodTemplate.Template,
+					Replicas:       2,
+					Selector:       &metav1.LabelSelector{MatchLabels: validLabels},
+					Template:       invalidPodTemplate.Template,
+					UpdateStrategy: apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},
@@ -423,6 +500,7 @@ func TestValidateStatefulSetUpdate(t *testing.T) {
 					Replicas:            -1,
 					Selector:            &metav1.LabelSelector{MatchLabels: validLabels},
 					Template:            validPodTemplate.Template,
+					UpdateStrategy:      apps.StatefulSetUpdateStrategy{Type: apps.RollingUpdateStatefulSetStrategyType},
 				},
 			},
 		},