Introduces all API changes needed for Configurable HPA PR

api/api-rules/violation_exceptions.list

@@ -83,6 +83,7 @@ API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta1,HorizontalP
 API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta1,HorizontalPodAutoscalerSpec,Metrics
 API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta1,HorizontalPodAutoscalerStatus,Conditions
 API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta1,HorizontalPodAutoscalerStatus,CurrentMetrics
+API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta2,HPAScalingRules,Policies
 API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta2,HorizontalPodAutoscalerList,Items
 API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta2,HorizontalPodAutoscalerSpec,Metrics
 API rule violation: list_type_missing,k8s.io/api/autoscaling/v2beta2,HorizontalPodAutoscalerStatus,Conditions

pkg/apis/autoscaling/annotations.go

@@ -32,3 +32,7 @@ const HorizontalPodAutoscalerConditionsAnnotation = "autoscaling.alpha.kubernete
 // metrics are present.  This is here because it's used by both the v2beta1 defaulting
 // logic, and the pseudo-defaulting done in v1 conversion.
 const DefaultCPUUtilization = 80
+
+// BehaviorSpecsAnnotation is the annotation which holds the HPA constraints specs
+// when converting the `Behavior` field from autoscaling/v2beta2
+const BehaviorSpecsAnnotation = "autoscaling.alpha.kubernetes.io/behavior"

pkg/apis/autoscaling/types.go

@@ -95,6 +95,90 @@ type HorizontalPodAutoscalerSpec struct {
 	// more information about how each type of metric must respond.
 	// +optional
 	Metrics []MetricSpec
+
+	// behavior configures the scaling behavior of the target
+	// in both Up and Down directions (scaleUp and scaleDown fields respectively).
+	// If not set, the default HPAScalingRules for scale up and scale down are used.
+	// +optional
+	Behavior *HorizontalPodAutoscalerBehavior
+}
+
+// HorizontalPodAutoscalerBehavior configures a scaling behavior for Up and Down direction
+// (scaleUp and scaleDown fields respectively).
+type HorizontalPodAutoscalerBehavior struct {
+	// scaleUp is scaling policy for scaling Up.
+	// If not set, the default value is the higher of:
+	//   * increase no more than 4 pods per 60 seconds
+	//   * double the number of pods per 60 seconds
+	// No stabilization is used.
+	// +optional
+	ScaleUp *HPAScalingRules
+	// scaleDown is scaling policy for scaling Down.
+	// If not set, the default value is to allow to scale down to minReplicas pods, with a
+	// 300 second stabilization window (i.e., the highest recommendation for
+	// the last 300sec is used).
+	// +optional
+	ScaleDown *HPAScalingRules
+}
+
+// ScalingPolicySelect is used to specify which policy should be used while scaling in a certain direction
+type ScalingPolicySelect string
+
+const (
+	// MaxPolicySelect selects the policy with the highest possible change.
+	MaxPolicySelect ScalingPolicySelect = "Max"
+	// MinPolicySelect selects the policy with the lowest possible change.
+	MinPolicySelect ScalingPolicySelect = "Min"
+	// DisabledPolicySelect disables the scaling in this direction.
+	DisabledPolicySelect ScalingPolicySelect = "Disabled"
+)
+
+// HPAScalingRules configures the scaling behavior for one direction.
+// These Rules are applied after calculating DesiredReplicas from metrics for the HPA.
+// They can limit the scaling velocity by specifying scaling policies.
+// They can prevent flapping by specifying the stabilization window, so that the
+// number of replicas is not set instantly, instead, the safest value from the stabilization
+// window is chosen.
+type HPAScalingRules struct {
+	// StabilizationWindowSeconds is the number of seconds for which past recommendations should be
+	// considered while scaling up or scaling down.
+	// StabilizationWindowSeconds must be greater than or equal to zero and less than or equal to 3600 (one hour).
+	// If not set, use the default values:
+	// - For scale up: 0 (i.e. no stabilization is done).
+	// - For scale down: 300 (i.e. the stabilization window is 300 seconds long).
+	// +optional
+	StabilizationWindowSeconds *int32
+	// selectPolicy is used to specify which policy should be used.
+	// If not set, the default value MaxPolicySelect is used.
+	// +optional
+	SelectPolicy *ScalingPolicySelect
+	// policies is a list of potential scaling polices which can used during scaling.
+	// At least one policy must be specified, otherwise the HPAScalingRules will be discarded as invalid
+	// +optional
+	Policies []HPAScalingPolicy
+}
+
+// HPAScalingPolicyType is the type of the policy which could be used while making scaling decisions.
+type HPAScalingPolicyType string
+
+const (
+	// PodsScalingPolicy is a policy used to specify a change in absolute number of pods.
+	PodsScalingPolicy HPAScalingPolicyType = "Pods"
+	// PercentScalingPolicy is a policy used to specify a relative amount of change with respect to
+	// the current number of pods.
+	PercentScalingPolicy HPAScalingPolicyType = "Percent"
+)
+
+// HPAScalingPolicy is a single policy which must hold true for a specified past interval.
+type HPAScalingPolicy struct {
+	// Type is used to specify the scaling policy.
+	Type HPAScalingPolicyType
+	// Value contains the amount of change which is permitted by the policy.
+	// It must be greater than zero
+	Value int32
+	// PeriodSeconds specifies the window of time for which the policy should hold true.
+	// PeriodSeconds must be greater than zero and less than or equal to 1800 (30 min).
+	PeriodSeconds int32
 }
 
 // MetricSourceType indicates the type of metric.

pkg/apis/autoscaling/v1/conversion.go

@@ -289,9 +289,9 @@ func Convert_autoscaling_HorizontalPodAutoscaler_To_v1_HorizontalPodAutoscaler(i
 		}
 	}
 
-	if len(otherMetrics) > 0 || len(in.Status.CurrentMetrics) > 0 || len(currentConditions) > 0 {
+	if len(otherMetrics) > 0 || len(in.Status.CurrentMetrics) > 0 || len(currentConditions) > 0 || in.Spec.Behavior != nil {
 		old := out.Annotations
-		out.Annotations = make(map[string]string, len(old)+3)
+		out.Annotations = make(map[string]string, len(old)+4)
 		for k, v := range old {
 			out.Annotations[k] = v
 		}
@@ -313,6 +313,14 @@ func Convert_autoscaling_HorizontalPodAutoscaler_To_v1_HorizontalPodAutoscaler(i
 		out.Annotations[autoscaling.MetricStatusesAnnotation] = string(currentMetricsEnc)
 	}
 
+	if in.Spec.Behavior != nil {
+		behaviorEnc, err := json.Marshal(in.Spec.Behavior)
+		if err != nil {
+			return err
+		}
+		out.Annotations[autoscaling.BehaviorSpecsAnnotation] = string(behaviorEnc)
+	}
+
 	if len(in.Status.Conditions) > 0 {
 		currentConditionsEnc, err := json.Marshal(currentConditions)
 		if err != nil {
@@ -349,6 +357,15 @@ func Convert_v1_HorizontalPodAutoscaler_To_autoscaling_HorizontalPodAutoscaler(i
 		delete(out.Annotations, autoscaling.MetricSpecsAnnotation)
 	}
 
+	if behaviorEnc, hasConstraints := out.Annotations[autoscaling.BehaviorSpecsAnnotation]; hasConstraints {
+		var behavior autoscaling.HorizontalPodAutoscalerBehavior
+		if err := json.Unmarshal([]byte(behaviorEnc), &behavior); err != nil {
+			return err
+		}
+		out.Spec.Behavior = &behavior
+		delete(out.Annotations, autoscaling.BehaviorSpecsAnnotation)
+	}
+
 	if currentMetricsEnc, hasCurrentMetrics := out.Annotations[autoscaling.MetricStatusesAnnotation]; hasCurrentMetrics {
 		// ignore any existing status values -- the ones here have more information
 		var currentMetrics []autoscalingv1.MetricStatus

pkg/apis/autoscaling/v2beta1/conversion.go

@@ -17,6 +17,8 @@ limitations under the License.
 package v2beta1
 
 import (
+	"encoding/json"
+
 	autoscalingv2beta1 "k8s.io/api/autoscaling/v2beta1"
 
 	v1 "k8s.io/api/core/v1"
@@ -257,3 +259,45 @@ func Convert_v2beta1_PodsMetricStatus_To_autoscaling_PodsMetricStatus(in *autosc
 	}
 	return nil
 }
+
+func Convert_autoscaling_HorizontalPodAutoscaler_To_v2beta1_HorizontalPodAutoscaler(in *autoscaling.HorizontalPodAutoscaler, out *autoscalingv2beta1.HorizontalPodAutoscaler, s conversion.Scope) error {
+	if err := autoConvert_autoscaling_HorizontalPodAutoscaler_To_v2beta1_HorizontalPodAutoscaler(in, out, s); err != nil {
+		return err
+	}
+	if in.Spec.Behavior != nil {
+		old := out.Annotations
+		out.Annotations = make(map[string]string, len(old)+1)
+		for k, v := range old {
+			out.Annotations[k] = v
+		}
+
+		behaviorEnc, err := json.Marshal(in.Spec.Behavior)
+		if err != nil {
+			return err
+		}
+		// Even if the annotation for behavior exists, we will just overwrite it
+		out.Annotations[autoscaling.BehaviorSpecsAnnotation] = string(behaviorEnc)
+	}
+
+	return nil
+}
+
+func Convert_v2beta1_HorizontalPodAutoscaler_To_autoscaling_HorizontalPodAutoscaler(in *autoscalingv2beta1.HorizontalPodAutoscaler, out *autoscaling.HorizontalPodAutoscaler, s conversion.Scope) error {
+	if err := autoConvert_v2beta1_HorizontalPodAutoscaler_To_autoscaling_HorizontalPodAutoscaler(in, out, s); err != nil {
+		return err
+	}
+
+	if behaviorEnc, hasBehaviors := out.Annotations[autoscaling.BehaviorSpecsAnnotation]; hasBehaviors {
+		var behavior autoscaling.HorizontalPodAutoscalerBehavior
+		if err := json.Unmarshal([]byte(behaviorEnc), &behavior); err != nil {
+			return err
+		}
+		out.Spec.Behavior = &behavior
+		delete(out.Annotations, autoscaling.BehaviorSpecsAnnotation)
+	}
+	return nil
+}
+
+func Convert_autoscaling_HorizontalPodAutoscalerSpec_To_v2beta1_HorizontalPodAutoscalerSpec(in *autoscaling.HorizontalPodAutoscalerSpec, out *autoscalingv2beta1.HorizontalPodAutoscalerSpec, s conversion.Scope) error {
+	return autoConvert_autoscaling_HorizontalPodAutoscalerSpec_To_v2beta1_HorizontalPodAutoscalerSpec(in, out, s)
+}

staging/src/k8s.io/api/autoscaling/v2beta2/types.go

@@ -72,6 +72,12 @@ type HorizontalPodAutoscalerSpec struct {
 	// If not set, the default metric will be set to 80% average CPU utilization.
 	// +optional
 	Metrics []MetricSpec `json:"metrics,omitempty" protobuf:"bytes,4,rep,name=metrics"`
+
+	// behavior configures the scaling behavior of the target
+	// in both Up and Down directions (scaleUp and scaleDown fields respectively).
+	// If not set, the default HPAScalingRules for scale up and scale down are used.
+	// +optional
+	Behavior *HorizontalPodAutoscalerBehavior `json:"behavior,omitempty" protobuf:"bytes,5,opt,name=behavior"`
 }
 
 // CrossVersionObjectReference contains enough information to let you identify the referred resource.
@@ -117,6 +123,84 @@ type MetricSpec struct {
 	External *ExternalMetricSource `json:"external,omitempty" protobuf:"bytes,5,opt,name=external"`
 }
 
+// HorizontalPodAutoscalerBehavior configures the scaling behavior of the target
+// in both Up and Down directions (scaleUp and scaleDown fields respectively).
+type HorizontalPodAutoscalerBehavior struct {
+	// scaleUp is scaling policy for scaling Up.
+	// If not set, the default value is the higher of:
+	//   * increase no more than 4 pods per 60 seconds
+	//   * double the number of pods per 60 seconds
+	// No stabilization is used.
+	// +optional
+	ScaleUp *HPAScalingRules `json:"scaleUp,omitempty" protobuf:"bytes,1,opt,name=scaleUp"`
+	// scaleDown is scaling policy for scaling Down.
+	// If not set, the default value is to allow to scale down to minReplicas pods, with a
+	// 300 second stabilization window (i.e., the highest recommendation for
+	// the last 300sec is used).
+	// +optional
+	ScaleDown *HPAScalingRules `json:"scaleDown,omitempty" protobuf:"bytes,2,opt,name=scaleDown"`
+}
+
+// ScalingPolicySelect is used to specify which policy should be used while scaling in a certain direction
+type ScalingPolicySelect string
+
+const (
+	// MaxPolicySelect selects the policy with the highest possible change.
+	MaxPolicySelect ScalingPolicySelect = "Max"
+	// MinPolicySelect selects the policy with the lowest possible change.
+	MinPolicySelect ScalingPolicySelect = "Min"
+	// DisabledPolicySelect disables the scaling in this direction.
+	DisabledPolicySelect ScalingPolicySelect = "Disabled"
+)
+
+// HPAScalingRules configures the scaling behavior for one direction.
+// These Rules are applied after calculating DesiredReplicas from metrics for the HPA.
+// They can limit the scaling velocity by specifying scaling policies.
+// They can prevent flapping by specifying the stabilization window, so that the
+// number of replicas is not set instantly, instead, the safest value from the stabilization
+// window is chosen.
+type HPAScalingRules struct {
+	// StabilizationWindowSeconds is the number of seconds for which past recommendations should be
+	// considered while scaling up or scaling down.
+	// StabilizationWindowSeconds must be greater than or equal to zero and less than or equal to 3600 (one hour).
+	// If not set, use the default values:
+	// - For scale up: 0 (i.e. no stabilization is done).
+	// - For scale down: 300 (i.e. the stabilization window is 300 seconds long).
+	// +optional
+	StabilizationWindowSeconds *int32 `json:"stabilizationWindowSeconds" protobuf:"varint,3,opt,name=stabilizationWindowSeconds"`
+	// selectPolicy is used to specify which policy should be used.
+	// If not set, the default value MaxPolicySelect is used.
+	// +optional
+	SelectPolicy *ScalingPolicySelect `json:"selectPolicy,omitempty" protobuf:"bytes,1,opt,name=selectPolicy"`
+	// policies is a list of potential scaling polices which can be used during scaling.
+	// At least one policy must be specified, otherwise the HPAScalingRules will be discarded as invalid
+	// +optional
+	Policies []HPAScalingPolicy `json:"policies,omitempty" protobuf:"bytes,2,rep,name=policies"`
+}
+
+// HPAScalingPolicyType is the type of the policy which could be used while making scaling decisions.
+type HPAScalingPolicyType string
+
+const (
+	// PodsScalingPolicy is a policy used to specify a change in absolute number of pods.
+	PodsScalingPolicy HPAScalingPolicyType = "Pods"
+	// PercentScalingPolicy is a policy used to specify a relative amount of change with respect to
+	// the current number of pods.
+	PercentScalingPolicy HPAScalingPolicyType = "Percent"
+)
+
+// HPAScalingPolicy is a single policy which must hold true for a specified past interval.
+type HPAScalingPolicy struct {
+	// Type is used to specify the scaling policy.
+	Type HPAScalingPolicyType `json:"type" protobuf:"bytes,1,opt,name=type,casttype=HPAScalingPolicyType"`
+	// Value contains the amount of change which is permitted by the policy.
+	// It must be greater than zero
+	Value int32 `json:"value" protobuf:"varint,2,opt,name=value"`
+	// PeriodSeconds specifies the window of time for which the policy should hold true.
+	// PeriodSeconds must be greater than zero and less than or equal to 1800 (30 min).
+	PeriodSeconds int32 `json:"periodSeconds" protobuf:"varint,3,opt,name=periodSeconds"`
+}
+
 // MetricSourceType indicates the type of metric.
 type MetricSourceType string