Added HorizontalPodAutoscaler object to experimental API.

Added HorizontalPodAutoscaler object to experimental API. Related to #12087.

pkg/expapi/deep_copy_generated.go

@@ -21,10 +21,18 @@ import (
 	time "time"
 
 	api "k8s.io/kubernetes/pkg/api"
+	resource "k8s.io/kubernetes/pkg/api/resource"
 	conversion "k8s.io/kubernetes/pkg/conversion"
 	util "k8s.io/kubernetes/pkg/util"
+	inf "speter.net/go/exp/math/dec/inf"
 )
 
+func deepCopy_api_ListMeta(in api.ListMeta, out *api.ListMeta, c *conversion.Cloner) error {
+	out.SelfLink = in.SelfLink
+	out.ResourceVersion = in.ResourceVersion
+	return nil
+}
+
 func deepCopy_api_ObjectMeta(in api.ObjectMeta, out *api.ObjectMeta, c *conversion.Cloner) error {
 	out.Name = in.Name
 	out.GenerateName = in.GenerateName
@@ -69,6 +77,72 @@ func deepCopy_api_TypeMeta(in api.TypeMeta, out *api.TypeMeta, c *conversion.Clo
 	return nil
 }
 
+func deepCopy_resource_Quantity(in resource.Quantity, out *resource.Quantity, c *conversion.Cloner) error {
+	if in.Amount != nil {
+		if newVal, err := c.DeepCopy(in.Amount); err != nil {
+			return err
+		} else if newVal == nil {
+			out.Amount = nil
+		} else {
+			out.Amount = newVal.(*inf.Dec)
+		}
+	} else {
+		out.Amount = nil
+	}
+	out.Format = in.Format
+	return nil
+}
+
+func deepCopy_expapi_HorizontalPodAutoscaler(in HorizontalPodAutoscaler, out *HorizontalPodAutoscaler, c *conversion.Cloner) error {
+	if err := deepCopy_api_TypeMeta(in.TypeMeta, &out.TypeMeta, c); err != nil {
+		return err
+	}
+	if err := deepCopy_api_ObjectMeta(in.ObjectMeta, &out.ObjectMeta, c); err != nil {
+		return err
+	}
+	if err := deepCopy_expapi_HorizontalPodAutoscalerSpec(in.Spec, &out.Spec, c); err != nil {
+		return err
+	}
+	return nil
+}
+
+func deepCopy_expapi_HorizontalPodAutoscalerList(in HorizontalPodAutoscalerList, out *HorizontalPodAutoscalerList, c *conversion.Cloner) error {
+	if err := deepCopy_api_TypeMeta(in.TypeMeta, &out.TypeMeta, c); err != nil {
+		return err
+	}
+	if err := deepCopy_api_ListMeta(in.ListMeta, &out.ListMeta, c); err != nil {
+		return err
+	}
+	if in.Items != nil {
+		out.Items = make([]HorizontalPodAutoscaler, len(in.Items))
+		for i := range in.Items {
+			if err := deepCopy_expapi_HorizontalPodAutoscaler(in.Items[i], &out.Items[i], c); err != nil {
+				return err
+			}
+		}
+	} else {
+		out.Items = nil
+	}
+	return nil
+}
+
+func deepCopy_expapi_HorizontalPodAutoscalerSpec(in HorizontalPodAutoscalerSpec, out *HorizontalPodAutoscalerSpec, c *conversion.Cloner) error {
+	if in.ScaleRef != nil {
+		out.ScaleRef = new(SubresourceReference)
+		if err := deepCopy_expapi_SubresourceReference(*in.ScaleRef, out.ScaleRef, c); err != nil {
+			return err
+		}
+	} else {
+		out.ScaleRef = nil
+	}
+	out.MinCount = in.MinCount
+	out.MaxCount = in.MaxCount
+	if err := deepCopy_expapi_TargetConsumption(in.Target, &out.Target, c); err != nil {
+		return err
+	}
+	return nil
+}
+
 func deepCopy_expapi_ReplicationControllerDummy(in ReplicationControllerDummy, out *ReplicationControllerDummy, c *conversion.Cloner) error {
 	if err := deepCopy_api_TypeMeta(in.TypeMeta, &out.TypeMeta, c); err != nil {
 		return err
@@ -110,6 +184,23 @@ func deepCopy_expapi_ScaleStatus(in ScaleStatus, out *ScaleStatus, c *conversion
 	return nil
 }
 
+func deepCopy_expapi_SubresourceReference(in SubresourceReference, out *SubresourceReference, c *conversion.Cloner) error {
+	out.Kind = in.Kind
+	out.Namespace = in.Namespace
+	out.Name = in.Name
+	out.APIVersion = in.APIVersion
+	out.Subresource = in.Subresource
+	return nil
+}
+
+func deepCopy_expapi_TargetConsumption(in TargetConsumption, out *TargetConsumption, c *conversion.Cloner) error {
+	out.Resource = in.Resource
+	if err := deepCopy_resource_Quantity(in.Quantity, &out.Quantity, c); err != nil {
+		return err
+	}
+	return nil
+}
+
 func deepCopy_util_Time(in util.Time, out *util.Time, c *conversion.Cloner) error {
 	if newVal, err := c.DeepCopy(in.Time); err != nil {
 		return err
@@ -121,12 +212,19 @@ func deepCopy_util_Time(in util.Time, out *util.Time, c *conversion.Cloner) erro
 
 func init() {
 	err := api.Scheme.AddGeneratedDeepCopyFuncs(
+		deepCopy_api_ListMeta,
 		deepCopy_api_ObjectMeta,
 		deepCopy_api_TypeMeta,
+		deepCopy_resource_Quantity,
+		deepCopy_expapi_HorizontalPodAutoscaler,
+		deepCopy_expapi_HorizontalPodAutoscalerList,
+		deepCopy_expapi_HorizontalPodAutoscalerSpec,
 		deepCopy_expapi_ReplicationControllerDummy,
 		deepCopy_expapi_Scale,
 		deepCopy_expapi_ScaleSpec,
 		deepCopy_expapi_ScaleStatus,
+		deepCopy_expapi_SubresourceReference,
+		deepCopy_expapi_TargetConsumption,
 		deepCopy_util_Time,
 	)
 	if err != nil {

pkg/expapi/register.go

@@ -27,8 +27,15 @@ func init() {
 
 // Adds the list of known types to api.Scheme.
 func addKnownTypes() {
-	api.Scheme.AddKnownTypes("", &Scale{}, &ReplicationControllerDummy{})
+	api.Scheme.AddKnownTypes("",
+		&HorizontalPodAutoscaler{},
+		&HorizontalPodAutoscalerList{},
+		&ReplicationControllerDummy{},
+		&Scale{},
+	)
 }
 
-func (*Scale) IsAnAPIObject()                      {}
+func (*HorizontalPodAutoscaler) IsAnAPIObject()     {}
-func (*ReplicationControllerDummy) IsAnAPIObject() {}
+func (*HorizontalPodAutoscalerList) IsAnAPIObject() {}
+func (*ReplicationControllerDummy) IsAnAPIObject()  {}
+func (*Scale) IsAnAPIObject()                       {}

pkg/expapi/types.go

@@ -28,7 +28,10 @@ support is experimental.
 
 package expapi
 
-import "k8s.io/kubernetes/pkg/api"
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/resource"
+)
 
 // ScaleSpec describes the attributes a Scale subresource
 type ScaleSpec struct {
@@ -61,3 +64,49 @@ type Scale struct {
 type ReplicationControllerDummy struct {
 	api.TypeMeta `json:",inline"`
 }
+
+// SubresourceReference contains enough information to let you inspect or modify the referred subresource.
+type SubresourceReference struct {
+	Kind        string `json:"kind,omitempty"`
+	Namespace   string `json:"namespace,omitempty"`
+	Name        string `json:"name,omitempty"`
+	APIVersion  string `json:"apiVersion,omitempty"`
+	Subresource string `json:"subresource,omitempty"`
+}
+
+// TargetConsumption is an object for specifying target average resource consumption of a particular resource.
+type TargetConsumption struct {
+	Resource api.ResourceName  `json:"resource,omitempty"`
+	Quantity resource.Quantity `json:"quantity,omitempty"`
+}
+
+// HorizontalPodAutoscalerSpec is the specification of a horizontal pod autoscaler.
+type HorizontalPodAutoscalerSpec struct {
+	// ScaleRef is a reference to Scale subresource. HorizontalPodAutoscaler will learn the current resource consumption from its status,
+	// and will set the desired number of pods by modyfying its spec.
+	ScaleRef *SubresourceReference `json:"scaleRef"`
+	// MinCount is the lower limit for the number of pods that can be set by the autoscaler.
+	MinCount int `json:"minCount"`
+	// MaxCount is the upper limit for the number of pods that can be set by the autoscaler. It cannot be smaller than MinCount.
+	MaxCount int `json:"maxCount"`
+	// Target is the target average consumption of the given resource that the autoscaler will try to maintain by adjusting the desired number of pods.
+	// Currently two types of resources are supported: "cpu" and "memory".
+	Target TargetConsumption `json:"target"`
+}
+
+// HorizontalPodAutoscaler represents the configuration of a horizontal pod autoscaler.
+type HorizontalPodAutoscaler struct {
+	api.TypeMeta   `json:",inline"`
+	api.ObjectMeta `json:"metadata,omitempty"`
+
+	// Spec defines the behaviour of autoscaler.
+	Spec HorizontalPodAutoscalerSpec `json:"spec,omitempty"`
+}
+
+// HorizontalPodAutoscaler is a collection of pod autoscalers.
+type HorizontalPodAutoscalerList struct {
+	api.TypeMeta `json:",inline"`
+	api.ListMeta `json:"metadata,omitempty"`
+
+	Items []HorizontalPodAutoscaler `json:"items"`
+}

pkg/expapi/v1/deep_copy_generated.go

@@ -21,11 +21,79 @@ import (
 	time "time"
 
 	api "k8s.io/kubernetes/pkg/api"
+	resource "k8s.io/kubernetes/pkg/api/resource"
 	v1 "k8s.io/kubernetes/pkg/api/v1"
 	conversion "k8s.io/kubernetes/pkg/conversion"
 	util "k8s.io/kubernetes/pkg/util"
+	inf "speter.net/go/exp/math/dec/inf"
 )
 
+func deepCopy_api_ListMeta(in api.ListMeta, out *api.ListMeta, c *conversion.Cloner) error {
+	out.SelfLink = in.SelfLink
+	out.ResourceVersion = in.ResourceVersion
+	return nil
+}
+
+func deepCopy_api_ObjectMeta(in api.ObjectMeta, out *api.ObjectMeta, c *conversion.Cloner) error {
+	out.Name = in.Name
+	out.GenerateName = in.GenerateName
+	out.Namespace = in.Namespace
+	out.SelfLink = in.SelfLink
+	out.UID = in.UID
+	out.ResourceVersion = in.ResourceVersion
+	out.Generation = in.Generation
+	if err := deepCopy_util_Time(in.CreationTimestamp, &out.CreationTimestamp, c); err != nil {
+		return err
+	}
+	if in.DeletionTimestamp != nil {
+		out.DeletionTimestamp = new(util.Time)
+		if err := deepCopy_util_Time(*in.DeletionTimestamp, out.DeletionTimestamp, c); err != nil {
+			return err
+		}
+	} else {
+		out.DeletionTimestamp = nil
+	}
+	if in.Labels != nil {
+		out.Labels = make(map[string]string)
+		for key, val := range in.Labels {
+			out.Labels[key] = val
+		}
+	} else {
+		out.Labels = nil
+	}
+	if in.Annotations != nil {
+		out.Annotations = make(map[string]string)
+		for key, val := range in.Annotations {
+			out.Annotations[key] = val
+		}
+	} else {
+		out.Annotations = nil
+	}
+	return nil
+}
+
+func deepCopy_api_TypeMeta(in api.TypeMeta, out *api.TypeMeta, c *conversion.Cloner) error {
+	out.Kind = in.Kind
+	out.APIVersion = in.APIVersion
+	return nil
+}
+
+func deepCopy_resource_Quantity(in resource.Quantity, out *resource.Quantity, c *conversion.Cloner) error {
+	if in.Amount != nil {
+		if newVal, err := c.DeepCopy(in.Amount); err != nil {
+			return err
+		} else if newVal == nil {
+			out.Amount = nil
+		} else {
+			out.Amount = newVal.(*inf.Dec)
+		}
+	} else {
+		out.Amount = nil
+	}
+	out.Format = in.Format
+	return nil
+}
+
 func deepCopy_v1_ObjectMeta(in v1.ObjectMeta, out *v1.ObjectMeta, c *conversion.Cloner) error {
 	out.Name = in.Name
 	out.GenerateName = in.GenerateName
@@ -70,6 +138,56 @@ func deepCopy_v1_TypeMeta(in v1.TypeMeta, out *v1.TypeMeta, c *conversion.Cloner
 	return nil
 }
 
+func deepCopy_v1_HorizontalPodAutoscaler(in HorizontalPodAutoscaler, out *HorizontalPodAutoscaler, c *conversion.Cloner) error {
+	if err := deepCopy_api_TypeMeta(in.TypeMeta, &out.TypeMeta, c); err != nil {
+		return err
+	}
+	if err := deepCopy_api_ObjectMeta(in.ObjectMeta, &out.ObjectMeta, c); err != nil {
+		return err
+	}
+	if err := deepCopy_v1_HorizontalPodAutoscalerSpec(in.Spec, &out.Spec, c); err != nil {
+		return err
+	}
+	return nil
+}
+
+func deepCopy_v1_HorizontalPodAutoscalerList(in HorizontalPodAutoscalerList, out *HorizontalPodAutoscalerList, c *conversion.Cloner) error {
+	if err := deepCopy_api_TypeMeta(in.TypeMeta, &out.TypeMeta, c); err != nil {
+		return err
+	}
+	if err := deepCopy_api_ListMeta(in.ListMeta, &out.ListMeta, c); err != nil {
+		return err
+	}
+	if in.Items != nil {
+		out.Items = make([]HorizontalPodAutoscaler, len(in.Items))
+		for i := range in.Items {
+			if err := deepCopy_v1_HorizontalPodAutoscaler(in.Items[i], &out.Items[i], c); err != nil {
+				return err
+			}
+		}
+	} else {
+		out.Items = nil
+	}
+	return nil
+}
+
+func deepCopy_v1_HorizontalPodAutoscalerSpec(in HorizontalPodAutoscalerSpec, out *HorizontalPodAutoscalerSpec, c *conversion.Cloner) error {
+	if in.ScaleRef != nil {
+		out.ScaleRef = new(SubresourceReference)
+		if err := deepCopy_v1_SubresourceReference(*in.ScaleRef, out.ScaleRef, c); err != nil {
+			return err
+		}
+	} else {
+		out.ScaleRef = nil
+	}
+	out.MinCount = in.MinCount
+	out.MaxCount = in.MaxCount
+	if err := deepCopy_v1_TargetConsumption(in.Target, &out.Target, c); err != nil {
+		return err
+	}
+	return nil
+}
+
 func deepCopy_v1_ReplicationControllerDummy(in ReplicationControllerDummy, out *ReplicationControllerDummy, c *conversion.Cloner) error {
 	if err := deepCopy_v1_TypeMeta(in.TypeMeta, &out.TypeMeta, c); err != nil {
 		return err
@@ -111,6 +229,23 @@ func deepCopy_v1_ScaleStatus(in ScaleStatus, out *ScaleStatus, c *conversion.Clo
 	return nil
 }
 
+func deepCopy_v1_SubresourceReference(in SubresourceReference, out *SubresourceReference, c *conversion.Cloner) error {
+	out.Kind = in.Kind
+	out.Namespace = in.Namespace
+	out.Name = in.Name
+	out.APIVersion = in.APIVersion
+	out.Subresource = in.Subresource
+	return nil
+}
+
+func deepCopy_v1_TargetConsumption(in TargetConsumption, out *TargetConsumption, c *conversion.Cloner) error {
+	out.Resource = in.Resource
+	if err := deepCopy_resource_Quantity(in.Quantity, &out.Quantity, c); err != nil {
+		return err
+	}
+	return nil
+}
+
 func deepCopy_util_Time(in util.Time, out *util.Time, c *conversion.Cloner) error {
 	if newVal, err := c.DeepCopy(in.Time); err != nil {
 		return err
@@ -122,12 +257,21 @@ func deepCopy_util_Time(in util.Time, out *util.Time, c *conversion.Cloner) erro
 
 func init() {
 	err := api.Scheme.AddGeneratedDeepCopyFuncs(
+		deepCopy_api_ListMeta,
+		deepCopy_api_ObjectMeta,
+		deepCopy_api_TypeMeta,
+		deepCopy_resource_Quantity,
 		deepCopy_v1_ObjectMeta,
 		deepCopy_v1_TypeMeta,
+		deepCopy_v1_HorizontalPodAutoscaler,
+		deepCopy_v1_HorizontalPodAutoscalerList,
+		deepCopy_v1_HorizontalPodAutoscalerSpec,
 		deepCopy_v1_ReplicationControllerDummy,
 		deepCopy_v1_Scale,
 		deepCopy_v1_ScaleSpec,
 		deepCopy_v1_ScaleStatus,
+		deepCopy_v1_SubresourceReference,
+		deepCopy_v1_TargetConsumption,
 		deepCopy_util_Time,
 	)
 	if err != nil {

pkg/expapi/v1/register.go

@@ -24,15 +24,22 @@ import (
 var Codec = runtime.CodecFor(api.Scheme, "v1")
 
 func init() {
-	addConversionFuncs()
-	addDefaultingFuncs()
 	addKnownTypes()
+	addDefaultingFuncs()
+	addConversionFuncs()
 }
 
 // Adds the list of known types to api.Scheme.
 func addKnownTypes() {
-	api.Scheme.AddKnownTypes("v1", &Scale{}, &ReplicationControllerDummy{})
+	api.Scheme.AddKnownTypes("v1",
+		&HorizontalPodAutoscaler{},
+		&HorizontalPodAutoscalerList{},
+		&ReplicationControllerDummy{},
+		&Scale{},
+	)
 }
 
-func (*Scale) IsAnAPIObject()                      {}
+func (*HorizontalPodAutoscaler) IsAnAPIObject()     {}
-func (*ReplicationControllerDummy) IsAnAPIObject() {}
+func (*HorizontalPodAutoscalerList) IsAnAPIObject() {}
+func (*ReplicationControllerDummy) IsAnAPIObject()  {}
+func (*Scale) IsAnAPIObject()                       {}

pkg/expapi/v1/types.go

@@ -16,7 +16,11 @@ limitations under the License.
 
 package v1
 
-import "k8s.io/kubernetes/pkg/api/v1"
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/api/v1"
+)
 
 // ScaleSpec describes the attributes a Scale subresource
 type ScaleSpec struct {
@@ -49,3 +53,49 @@ type Scale struct {
 type ReplicationControllerDummy struct {
 	v1.TypeMeta `json:",inline"`
 }
+
+// SubresourceReference contains enough information to let you inspect or modify the referred subresource.
+type SubresourceReference struct {
+	Kind        string `json:"kind,omitempty" description:"kind of the referent; see http://releases.k8s.io/HEAD/docs/devel/api-conventions.md#types-kinds"`
+	Namespace   string `json:"namespace,omitempty" description:"namespace of the referent; see http://releases.k8s.io/HEAD/docs/user-guide/namespaces.md"`
+	Name        string `json:"name,omitempty" description:"name of the referent; see http://releases.k8s.io/HEAD/docs/user-guide/identifiers.md#names"`
+	APIVersion  string `json:"apiVersion,omitempty" description:"API version of the referent"`
+	Subresource string `json:"subresource,omitempty" decription:"subresource name of the referent"`
+}
+
+// TargetConsumption is an object for specifying target average resource consumption of a particular resource.
+type TargetConsumption struct {
+	Resource api.ResourceName  `json:"resource,omitempty"`
+	Quantity resource.Quantity `json:"quantity,omitempty"`
+}
+
+// HorizontalPodAutoscalerSpec is the specification of a horizontal pod autoscaler.
+type HorizontalPodAutoscalerSpec struct {
+	// ScaleRef is a reference to Scale subresource. HorizontalPodAutoscaler will learn the current resource consumption from its status,
+	// and will set the desired number of pods by modyfying its spec.
+	ScaleRef *SubresourceReference `json:"scaleRef" description:"reference to scale subresource for quering the current resource cosumption and for setting the desired number of pods"`
+	// MinCount is the lower limit for the number of pods that can be set by the autoscaler.
+	MinCount int `json:"minCount" description:"lower limit for the number of pods"`
+	// MaxCount is the upper limit for the number of pods that can be set by the autoscaler. It cannot be smaller than MinCount.
+	MaxCount int `json:"maxCount" description:"upper limit for the number of pods"`
+	// Target is the target average consumption of the given resource that the autoscaler will try to maintain by adjusting the desired number of pods.
+	// Currently two types of resources are supported: "cpu" and "memory".
+	Target TargetConsumption `json:"target"	description:"target average consumption of resource that the autoscaler will try to maintain by adjusting the desired number of pods"`
+}
+
+// HorizontalPodAutoscaler represents the configuration of a horizontal pod autoscaler.
+type HorizontalPodAutoscaler struct {
+	api.TypeMeta   `json:",inline"`
+	api.ObjectMeta `json:"metadata,omitempty"`
+
+	// Spec defines the behaviour of autoscaler.
+	Spec HorizontalPodAutoscalerSpec `json:"spec,omitempty" description:"specification of the desired behavior of the autoscaler; http://releases.k8s.io/HEAD/docs/devel/api-conventions.md#spec-and-status"`
+}
+
+// HorizontalPodAutoscaler is a collection of pod autoscalers.
+type HorizontalPodAutoscalerList struct {
+	api.TypeMeta `json:",inline"`
+	api.ListMeta `json:"metadata,omitempty"`
+
+	Items []HorizontalPodAutoscaler `json:"items" description:"list of horizontal pod autoscalers"`
+}

pkg/expapi/validation/validation.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 validation
+
+import (
+	"k8s.io/kubernetes/pkg/api"
+	apivalidation "k8s.io/kubernetes/pkg/api/validation"
+	"k8s.io/kubernetes/pkg/expapi"
+	errs "k8s.io/kubernetes/pkg/util/fielderrors"
+)
+
+// ValidateHorizontalPodAutoscaler can be used to check whether the given autoscaler name is valid.
+// Prefix indicates this name will be used as part of generation, in which case trailing dashes are allowed.
+func ValidateHorizontalPodAutoscalerName(name string, prefix bool) (bool, string) {
+	// TODO: finally move it to pkg/api/validation and use nameIsDNSSubdomain function
+	return apivalidation.ValidateReplicationControllerName(name, prefix)
+}
+
+func validateHorizontalPodAutoscalerSpec(autoscaler expapi.HorizontalPodAutoscalerSpec) errs.ValidationErrorList {
+	allErrs := errs.ValidationErrorList{}
+	if autoscaler.MinCount < 0 {
+		allErrs = append(allErrs, errs.NewFieldInvalid("minCount", autoscaler.MinCount, `must be non-negative`))
+	}
+	if autoscaler.MaxCount < autoscaler.MinCount {
+		allErrs = append(allErrs, errs.NewFieldInvalid("maxCount", autoscaler.MaxCount, `must be bigger or equal to minCount`))
+	}
+	if autoscaler.ScaleRef == nil {
+		allErrs = append(allErrs, errs.NewFieldRequired("scaleRef"))
+	}
+	resource := autoscaler.Target.Resource.String()
+	if resource != string(api.ResourceMemory) && resource != string(api.ResourceCPU) {
+		allErrs = append(allErrs, errs.NewFieldInvalid("target.resource", resource, "resource not supported by autoscaler"))
+	}
+	quantity := autoscaler.Target.Quantity.Value()
+	if quantity < 0 {
+		allErrs = append(allErrs, errs.NewFieldInvalid("target.quantity", quantity, "must be non-negative"))
+	}
+	return allErrs
+}
+
+func ValidateHorizontalPodAutoscaler(autoscaler *expapi.HorizontalPodAutoscaler) errs.ValidationErrorList {
+	allErrs := errs.ValidationErrorList{}
+	allErrs = append(allErrs, apivalidation.ValidateObjectMeta(&autoscaler.ObjectMeta, true, ValidateHorizontalPodAutoscalerName).Prefix("metadata")...)
+	allErrs = append(allErrs, validateHorizontalPodAutoscalerSpec(autoscaler.Spec)...)
+	return allErrs
+}
+
+func ValidateHorizontalPodAutoscalerUpdate(newAutoscler, oldAutoscaler *expapi.HorizontalPodAutoscaler) errs.ValidationErrorList {
+	allErrs := errs.ValidationErrorList{}
+	allErrs = append(allErrs, apivalidation.ValidateObjectMetaUpdate(&newAutoscler.ObjectMeta, &oldAutoscaler.ObjectMeta).Prefix("metadata")...)
+	allErrs = append(allErrs, validateHorizontalPodAutoscalerSpec(newAutoscler.Spec)...)
+	return allErrs
+}

pkg/expapi/validation/validation_test.go

@@ -0,0 +1,129 @@
+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+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 validation
+
+import (
+	"strings"
+	"testing"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/expapi"
+)
+
+func TestValidateHorizontalPodAutoscaler(t *testing.T) {
+	successCases := []expapi.HorizontalPodAutoscaler{
+		{
+			ObjectMeta: api.ObjectMeta{
+				Name:      "myautoscaler",
+				Namespace: api.NamespaceDefault,
+			},
+			Spec: expapi.HorizontalPodAutoscalerSpec{
+				ScaleRef: &expapi.SubresourceReference{
+					Subresource: "scale",
+				},
+				MinCount: 1,
+				MaxCount: 5,
+				Target:   expapi.TargetConsumption{api.ResourceCPU, resource.MustParse("0.8")},
+			},
+		},
+	}
+	for _, successCase := range successCases {
+		if errs := ValidateHorizontalPodAutoscaler(&successCase); len(errs) != 0 {
+			t.Errorf("expected success: %v", errs)
+		}
+	}
+
+	errorCases := map[string]expapi.HorizontalPodAutoscaler{
+		"must be non-negative": {
+			ObjectMeta: api.ObjectMeta{
+				Name:      "myautoscaler",
+				Namespace: api.NamespaceDefault,
+			},
+			Spec: expapi.HorizontalPodAutoscalerSpec{
+				ScaleRef: &expapi.SubresourceReference{
+					Subresource: "scale",
+				},
+				MinCount: -1,
+				MaxCount: 5,
+				Target:   expapi.TargetConsumption{api.ResourceCPU, resource.MustParse("0.8")},
+			},
+		},
+		"must be bigger or equal to minCount": {
+			ObjectMeta: api.ObjectMeta{
+				Name:      "myautoscaler",
+				Namespace: api.NamespaceDefault,
+			},
+			Spec: expapi.HorizontalPodAutoscalerSpec{
+				ScaleRef: &expapi.SubresourceReference{
+					Subresource: "scale",
+				},
+				MinCount: 7,
+				MaxCount: 5,
+				Target:   expapi.TargetConsumption{api.ResourceCPU, resource.MustParse("0.8")},
+			},
+		},
+		"invalid value": {
+			ObjectMeta: api.ObjectMeta{
+				Name:      "myautoscaler",
+				Namespace: api.NamespaceDefault,
+			},
+			Spec: expapi.HorizontalPodAutoscalerSpec{
+				ScaleRef: &expapi.SubresourceReference{
+					Subresource: "scale",
+				},
+				MinCount: 1,
+				MaxCount: 5,
+				Target:   expapi.TargetConsumption{api.ResourceCPU, resource.MustParse("-0.8")},
+			},
+		},
+		"resource not supported": {
+			ObjectMeta: api.ObjectMeta{
+				Name:      "myautoscaler",
+				Namespace: api.NamespaceDefault,
+			},
+			Spec: expapi.HorizontalPodAutoscalerSpec{
+				ScaleRef: &expapi.SubresourceReference{
+					Subresource: "scale",
+				},
+				MinCount: 1,
+				MaxCount: 5,
+				Target:   expapi.TargetConsumption{api.ResourceName("NotSupportedResource"), resource.MustParse("0.8")},
+			},
+		},
+		"required value": {
+			ObjectMeta: api.ObjectMeta{
+				Name:      "myautoscaler",
+				Namespace: api.NamespaceDefault,
+			},
+			Spec: expapi.HorizontalPodAutoscalerSpec{
+				MinCount: 1,
+				MaxCount: 5,
+				Target:   expapi.TargetConsumption{api.ResourceCPU, resource.MustParse("0.8")},
+			},
+		},
+	}
+
+	for k, v := range errorCases {
+		errs := ValidateHorizontalPodAutoscaler(&v)
+		if len(errs) == 0 {
+			t.Errorf("expected failure for %s", k)
+		} else if !strings.Contains(errs[0].Error(), k) {
+			t.Errorf("unexpected error: %v, expected: %s", errs[0], k)
+		}
+	}
+}

pkg/master/master.go

@@ -77,6 +77,8 @@ import (
 	"k8s.io/kubernetes/pkg/ui"
 	"k8s.io/kubernetes/pkg/util"
 
+	horizontalpodautoscaleretcd "k8s.io/kubernetes/pkg/registry/horizontalpodautoscaler/etcd"
+
 	"github.com/emicklei/go-restful"
 	"github.com/emicklei/go-restful/swagger"
 	"github.com/golang/glog"
@@ -777,11 +779,13 @@ func (m *Master) api_v1() *apiserver.APIGroupVersion {
 
 // expapi returns the resources and codec for the experimental api
 func (m *Master) expapi(c *Config) *apiserver.APIGroupVersion {
-
 	controllerStorage := expcontrolleretcd.NewStorage(c.DatabaseStorage)
+	autoscalerStorage := horizontalpodautoscaleretcd.NewREST(c.DatabaseStorage)
+
 	storage := map[string]rest.Storage{
 		strings.ToLower("replicationControllers"):       controllerStorage.ReplicationController,
 		strings.ToLower("replicationControllers/scale"): controllerStorage.Scale,
+		strings.ToLower("horizontalpodautoscalers"):     autoscalerStorage,
 	}
 
 	return &apiserver.APIGroupVersion{

pkg/registry/horizontalpodautoscaler/doc.go

@@ -0,0 +1,17 @@
+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+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 horizontalpodautoscaler

pkg/registry/horizontalpodautoscaler/etcd/etcd.go

@@ -0,0 +1,73 @@
+/*
+Copyright 2014 The Kubernetes Authors All rights reserved.
+
+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 etcd
+
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/expapi"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/registry/generic"
+	etcdgeneric "k8s.io/kubernetes/pkg/registry/generic/etcd"
+	"k8s.io/kubernetes/pkg/registry/horizontalpodautoscaler"
+	"k8s.io/kubernetes/pkg/runtime"
+	"k8s.io/kubernetes/pkg/storage"
+)
+
+// rest implements a RESTStorage for horizontal pod autoscalers against etcd
+type REST struct {
+	*etcdgeneric.Etcd
+}
+
+// NewREST returns a RESTStorage object that will work against horizontal pod autoscalers.
+func NewREST(s storage.Interface) *REST {
+	var prefix = "/horizontalpodautoscalers"
+	store := &etcdgeneric.Etcd{
+		NewFunc: func() runtime.Object { return &expapi.HorizontalPodAutoscaler{} },
+		// NewListFunc returns an object capable of storing results of an etcd list.
+		NewListFunc: func() runtime.Object { return &expapi.HorizontalPodAutoscalerList{} },
+		// Produces a path that etcd understands, to the root of the resource
+		// by combining the namespace in the context with the given prefix
+		KeyRootFunc: func(ctx api.Context) string {
+			return etcdgeneric.NamespaceKeyRootFunc(ctx, prefix)
+		},
+		// Produces a path that etcd understands, to the resource by combining
+		// the namespace in the context with the given prefix
+		KeyFunc: func(ctx api.Context, name string) (string, error) {
+			return etcdgeneric.NamespaceKeyFunc(ctx, prefix, name)
+		},
+		// Retrieve the name field of an autoscaler
+		ObjectNameFunc: func(obj runtime.Object) (string, error) {
+			return obj.(*expapi.HorizontalPodAutoscaler).Name, nil
+		},
+		// Used to match objects based on labels/fields for list
+		PredicateFunc: func(label labels.Selector, field fields.Selector) generic.Matcher {
+			return horizontalpodautoscaler.MatchAutoscaler(label, field)
+		},
+		EndpointName: "horizontalPodAutoscalers",
+
+		// Used to validate autoscaler creation
+		CreateStrategy: horizontalpodautoscaler.Strategy,
+
+		// Used to validate autoscaler updates
+		UpdateStrategy: horizontalpodautoscaler.Strategy,
+
+		Storage: s,
+	}
+
+	return &REST{store}
+}

pkg/registry/horizontalpodautoscaler/etcd/etcd_test.go

@@ -0,0 +1,231 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 etcd
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/api/rest/resttest"
+	"k8s.io/kubernetes/pkg/api/testapi"
+	"k8s.io/kubernetes/pkg/expapi"
+	"k8s.io/kubernetes/pkg/expapi/v1"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/runtime"
+	"k8s.io/kubernetes/pkg/storage"
+	etcdstorage "k8s.io/kubernetes/pkg/storage/etcd"
+	"k8s.io/kubernetes/pkg/tools"
+	"k8s.io/kubernetes/pkg/tools/etcdtest"
+
+	"github.com/coreos/go-etcd/etcd"
+)
+
+var scheme *runtime.Scheme
+var codec runtime.Codec
+
+func init() {
+	// Ensure that expapi/v1 packege is used, so that it will get initialized and register HorizontalPodAutoscaler object.
+	dummy := v1.HorizontalPodAutoscaler{}
+	dummy.Spec = v1.HorizontalPodAutoscalerSpec{}
+}
+
+func newStorage(t *testing.T) (*REST, *tools.FakeEtcdClient, storage.Interface) {
+	fakeEtcdClient := tools.NewFakeEtcdClient(t)
+	fakeEtcdClient.TestIndex = true
+	etcdStorage := etcdstorage.NewEtcdStorage(fakeEtcdClient, testapi.Codec(), etcdtest.PathPrefix())
+	storage := NewREST(etcdStorage)
+	return storage, fakeEtcdClient, etcdStorage
+}
+
+func validNewHorizontalPodAutoscaler(name string) *expapi.HorizontalPodAutoscaler {
+	return &expapi.HorizontalPodAutoscaler{
+		ObjectMeta: api.ObjectMeta{
+			Name:      name,
+			Namespace: api.NamespaceDefault,
+		},
+		Spec: expapi.HorizontalPodAutoscalerSpec{
+			ScaleRef: &expapi.SubresourceReference{
+				Subresource: "scale",
+			},
+			MinCount: 1,
+			MaxCount: 5,
+			Target:   expapi.TargetConsumption{api.ResourceCPU, resource.MustParse("0.8")},
+		},
+	}
+}
+
+func TestCreate(t *testing.T) {
+	storage, fakeEtcdClient, _ := newStorage(t)
+	test := resttest.New(t, storage, fakeEtcdClient.SetError)
+	autoscaler := validNewHorizontalPodAutoscaler("foo")
+	autoscaler.ObjectMeta = api.ObjectMeta{}
+	test.TestCreate(
+		// valid
+		autoscaler,
+		// invalid
+		&expapi.HorizontalPodAutoscaler{},
+	)
+}
+
+func TestUpdate(t *testing.T) {
+	storage, fakeEtcdClient, _ := newStorage(t)
+	test := resttest.New(t, storage, fakeEtcdClient.SetError)
+	key, err := storage.KeyFunc(test.TestContext(), "foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+	key = etcdtest.AddPrefix(key)
+	fakeEtcdClient.ExpectNotFoundGet(key)
+	fakeEtcdClient.ChangeIndex = 2
+	autoscaler := validNewHorizontalPodAutoscaler("foo")
+	existing := validNewHorizontalPodAutoscaler("exists")
+	existing.Namespace = test.TestNamespace()
+	obj, err := storage.Create(test.TestContext(), existing)
+	if err != nil {
+		t.Fatalf("unable to create object: %v", err)
+	}
+	older := obj.(*expapi.HorizontalPodAutoscaler)
+	older.ResourceVersion = "1"
+	test.TestUpdate(
+		autoscaler,
+		existing,
+		older,
+	)
+}
+
+func TestDelete(t *testing.T) {
+	ctx := api.NewDefaultContext()
+	storage, fakeEtcdClient, _ := newStorage(t)
+	test := resttest.New(t, storage, fakeEtcdClient.SetError)
+	autoscaler := validNewHorizontalPodAutoscaler("foo2")
+	key, _ := storage.KeyFunc(ctx, "foo2")
+	key = etcdtest.AddPrefix(key)
+	createFn := func() runtime.Object {
+		fakeEtcdClient.Data[key] = tools.EtcdResponseWithError{
+			R: &etcd.Response{
+				Node: &etcd.Node{
+					Value:         runtime.EncodeOrDie(testapi.Codec(), autoscaler),
+					ModifiedIndex: 1,
+				},
+			},
+		}
+		return autoscaler
+	}
+	gracefulSetFn := func() bool {
+		if fakeEtcdClient.Data[key].R.Node == nil {
+			return false
+		}
+		return fakeEtcdClient.Data[key].R.Node.TTL == 30
+	}
+	test.TestDeleteNoGraceful(createFn, gracefulSetFn)
+}
+
+func TestEtcdGet(t *testing.T) {
+	ctx := api.NewDefaultContext()
+	registry, fakeClient, _ := newStorage(t)
+	autoscaler := validNewHorizontalPodAutoscaler("foo3")
+	name := autoscaler.Name
+	key, _ := registry.KeyFunc(ctx, name)
+	key = etcdtest.AddPrefix(key)
+	fakeClient.Set(key, runtime.EncodeOrDie(testapi.Codec(), autoscaler), 0)
+	response, err := fakeClient.Get(key, false, false)
+	if err != nil {
+		t.Fatalf("Unexpected error %v", err)
+	}
+	var autoscalerOut expapi.HorizontalPodAutoscaler
+	err = testapi.Codec().DecodeInto([]byte(response.Node.Value), &autoscalerOut)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	obj, err := registry.Get(ctx, name)
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	got := obj.(*expapi.HorizontalPodAutoscaler)
+	autoscaler.ObjectMeta.ResourceVersion = got.ObjectMeta.ResourceVersion
+	if e, a := autoscaler, got; !api.Semantic.DeepEqual(*e, *a) {
+		t.Errorf("Unexpected autoscaler: %#v, expected %#v", e, a)
+	}
+}
+
+func TestEmptyList(t *testing.T) {
+	ctx := api.NewDefaultContext()
+	registry, fakeClient, _ := newStorage(t)
+	fakeClient.ChangeIndex = 1
+	key := registry.KeyRootFunc(ctx)
+	key = etcdtest.AddPrefix(key)
+	fakeClient.Data[key] = tools.EtcdResponseWithError{
+		R: &etcd.Response{},
+		E: fakeClient.NewError(tools.EtcdErrorCodeNotFound),
+	}
+	autoscalerList, err := registry.List(ctx, labels.Everything(), fields.Everything())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(autoscalerList.(*expapi.HorizontalPodAutoscalerList).Items) != 0 {
+		t.Errorf("Unexpected non-zero autoscaler list: %#v", autoscalerList)
+	}
+	if autoscalerList.(*expapi.HorizontalPodAutoscalerList).ResourceVersion != "1" {
+		t.Errorf("Unexpected resource version: %#v", autoscalerList)
+	}
+}
+
+func TestList(t *testing.T) {
+	ctx := api.NewDefaultContext()
+	registry, fakeClient, _ := newStorage(t)
+	fakeClient.ChangeIndex = 1
+	key := registry.KeyRootFunc(ctx)
+	key = etcdtest.AddPrefix(key)
+	fakeClient.Data[key] = tools.EtcdResponseWithError{
+		R: &etcd.Response{
+			Node: &etcd.Node{
+				Nodes: []*etcd.Node{
+					{
+						Value: runtime.EncodeOrDie(testapi.Codec(), &expapi.HorizontalPodAutoscaler{
+							ObjectMeta: api.ObjectMeta{Name: "foo"},
+						}),
+					},
+					{
+						Value: runtime.EncodeOrDie(testapi.Codec(), &expapi.HorizontalPodAutoscaler{
+							ObjectMeta: api.ObjectMeta{Name: "bar"},
+						}),
+					},
+				},
+			},
+		},
+	}
+	obj, err := registry.List(ctx, labels.Everything(), fields.Everything())
+	if err != nil {
+		t.Fatalf("Unexpected error %v", err)
+	}
+	autoscalerList := obj.(*expapi.HorizontalPodAutoscalerList)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if len(autoscalerList.Items) != 2 {
+		t.Errorf("Unexpected HorizontalPodAutoscaler list: %#v", autoscalerList)
+	}
+	if autoscalerList.Items[0].Name != "foo" {
+		t.Errorf("Unexpected HorizontalPodAutoscaler: %#v", autoscalerList.Items[0])
+	}
+	if autoscalerList.Items[1].Name != "bar" {
+		t.Errorf("Unexpected HorizontalPodAutoscaler: %#v", autoscalerList.Items[1])
+	}
+}

pkg/registry/horizontalpodautoscaler/registry.go

@@ -0,0 +1,80 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 horizontalpodautoscaler
+
+import (
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/rest"
+	"k8s.io/kubernetes/pkg/expapi"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+)
+
+// Registry is an interface implemented by things that know how to store HorizontalPodAutoscaler objects.
+type Registry interface {
+	// ListPersistentVolumes obtains a list of autoscalers having labels which match selector.
+	ListHorizontalPodAutoscaler(ctx api.Context, selector labels.Selector) (*expapi.HorizontalPodAutoscalerList, error)
+	// Get a specific autoscaler
+	GetHorizontalPodAutoscaler(ctx api.Context, autoscalerID string) (*expapi.HorizontalPodAutoscaler, error)
+	// Create an autoscaler based on a specification.
+	CreateHorizontalPodAutoscaler(ctx api.Context, autoscaler *expapi.HorizontalPodAutoscaler) error
+	// Update an existing autoscaler
+	UpdateHorizontalPodAutoscaler(ctx api.Context, autoscaler *expapi.HorizontalPodAutoscaler) error
+	// Delete an existing autoscaler
+	DeleteHorizontalPodAutoscaler(ctx api.Context, autoscalerID string) error
+}
+
+// storage puts strong typing around storage calls
+type storage struct {
+	rest.StandardStorage
+}
+
+// NewREST returns a new Registry interface for the given Storage. Any mismatched types will panic.
+func NewRegistry(s rest.StandardStorage) Registry {
+	return &storage{s}
+}
+
+func (s *storage) ListHorizontalPodAutoscaler(ctx api.Context, label labels.Selector) (*expapi.HorizontalPodAutoscalerList, error) {
+	obj, err := s.List(ctx, label, fields.Everything())
+	if err != nil {
+		return nil, err
+	}
+	return obj.(*expapi.HorizontalPodAutoscalerList), nil
+}
+
+func (s *storage) GetHorizontalPodAutoscaler(ctx api.Context, autoscalerID string) (*expapi.HorizontalPodAutoscaler, error) {
+	obj, err := s.Get(ctx, autoscalerID)
+	if err != nil {
+		return nil, err
+	}
+	return obj.(*expapi.HorizontalPodAutoscaler), nil
+}
+
+func (s *storage) CreateHorizontalPodAutoscaler(ctx api.Context, autoscaler *expapi.HorizontalPodAutoscaler) error {
+	_, err := s.Create(ctx, autoscaler)
+	return err
+}
+
+func (s *storage) UpdateHorizontalPodAutoscaler(ctx api.Context, autoscaler *expapi.HorizontalPodAutoscaler) error {
+	_, _, err := s.Update(ctx, autoscaler)
+	return err
+}
+
+func (s *storage) DeleteHorizontalPodAutoscaler(ctx api.Context, autoscalerID string) error {
+	_, err := s.Delete(ctx, autoscalerID, nil)
+	return err
+}

pkg/registry/horizontalpodautoscaler/rest.go

@@ -0,0 +1,86 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 horizontalpodautoscaler
+
+import (
+	"fmt"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/expapi"
+	"k8s.io/kubernetes/pkg/expapi/validation"
+	"k8s.io/kubernetes/pkg/fields"
+	"k8s.io/kubernetes/pkg/labels"
+	"k8s.io/kubernetes/pkg/registry/generic"
+	"k8s.io/kubernetes/pkg/runtime"
+	errs "k8s.io/kubernetes/pkg/util/fielderrors"
+)
+
+// autoscalerStrategy implements behavior for HorizontalPodAutoscalers
+type autoscalerStrategy struct {
+	runtime.ObjectTyper
+	api.NameGenerator
+}
+
+// Strategy is the default logic that applies when creating and updating HorizontalPodAutoscaler
+// objects via the REST API.
+var Strategy = autoscalerStrategy{api.Scheme, api.SimpleNameGenerator}
+
+// NamespaceScoped is true for autoscaler.
+func (autoscalerStrategy) NamespaceScoped() bool {
+	return true
+}
+
+// PrepareForCreate clears fields that are not allowed to be set by end users on creation.
+func (autoscalerStrategy) PrepareForCreate(obj runtime.Object) {
+	_ = obj.(*expapi.HorizontalPodAutoscaler)
+}
+
+// Validate validates a new autoscaler.
+func (autoscalerStrategy) Validate(ctx api.Context, obj runtime.Object) errs.ValidationErrorList {
+	autoscaler := obj.(*expapi.HorizontalPodAutoscaler)
+	return validation.ValidateHorizontalPodAutoscaler(autoscaler)
+}
+
+// AllowCreateOnUpdate is false for autoscalers.
+func (autoscalerStrategy) AllowCreateOnUpdate() bool {
+	return false
+}
+
+// PrepareForUpdate clears fields that are not allowed to be set by end users on update.
+func (autoscalerStrategy) PrepareForUpdate(obj, old runtime.Object) {
+	_ = obj.(*expapi.HorizontalPodAutoscaler)
+}
+
+// ValidateUpdate is the default update validation for an end user.
+func (autoscalerStrategy) ValidateUpdate(ctx api.Context, obj, old runtime.Object) errs.ValidationErrorList {
+	return validation.ValidateHorizontalPodAutoscalerUpdate(obj.(*expapi.HorizontalPodAutoscaler), old.(*expapi.HorizontalPodAutoscaler))
+}
+
+func (autoscalerStrategy) AllowUnconditionalUpdate() bool {
+	return true
+}
+
+// MatchAutoscaler returns a generic matcher for a given label and field selector.
+func MatchAutoscaler(label labels.Selector, field fields.Selector) generic.Matcher {
+	return generic.MatcherFunc(func(obj runtime.Object) (bool, error) {
+		autoscaler, ok := obj.(*expapi.HorizontalPodAutoscaler)
+		if !ok {
+			return false, fmt.Errorf("not a horizontal pod autoscaler")
+		}
+		return label.Matches(labels.Set(autoscaler.Labels)), nil
+	})
+}