measure

Documentation

Overview

Package measure provides functionality for measuring/retrieving metrics from the K8s metrics server.

Package measure provides K8s metric gathering, in the same way that the Horizontal Pod Autoscaler gathers metrics, using the metrics APIs.

Index

• type ExternalMetricSource
• type Gather
  • func NewGather(metricsClient metricsclient.MetricsClient, podlister corelisters.PodLister, ...) *Gather
  • func (c *Gather) GetMetrics(resource metav1.Object, specs []MetricSpec, namespace string) ([]*Metric, error)
• type Gatherer
• type Metric
• type MetricSpec
• type MetricTarget
• type ObjectMetricSource
• type PodsMetricSource
• type ResourceMetricSource

Types

type ExternalMetricSource

type ExternalMetricSource struct {
	Metric autoscaling.MetricIdentifier `json:"metric"`
	Target MetricTarget                 `json:"target"`
}

ExternalMetricSource defines gathering metrics for a metric not associated with any Kubernetes object (for example length of queue in cloud messaging service, or QPS from loadbalancer running outside of cluster).

type Gather

type Gather struct {
	Resource resource.Gatherer
	Pods     pods.Gatherer
	Object   object.Gatherer
	External external.Gatherer
}

Gather provides functionality for retrieving metrics on supplied metric specs.

func NewGather

func NewGather(
	metricsClient metricsclient.MetricsClient,
	podlister corelisters.PodLister,
	cpuInitializationPeriod time.Duration,
	delayOfInitialReadinessStatus time.Duration) *Gather

NewGather sets up a new Metric Gatherer

func (*Gather) GetMetrics

func (c *Gather) GetMetrics(resource metav1.Object, specs []MetricSpec, namespace string) ([]*Metric, error)

GetMetrics processes each MetricSpec provided, calculating metric values for each and combining them into a slice before returning them. Error will only be returned if all metrics are invalid, otherwise it will return the valid metrics.

type Gatherer

type Gatherer interface {
	GetMetrics(resource metav1.Object, specs []MetricSpec, namespace string) ([]*Metric, error)
}

Gatherer allows retrieval of metrics.

type Metric

type Metric struct {
	CurrentReplicas int32            `json:"current_replicas"`
	Spec            MetricSpec       `json:"spec"`
	Resource        *resource.Metric `json:"resource,omitempty"`
	Pods            *pods.Metric     `json:"pods,omitempty"`
	Object          *object.Metric   `json:"object,omitempty"`
	External        *external.Metric `json:"external,omitempty"`
}

Metric is a metric that has been retrieved from the K8s metrics server

type MetricSpec

type MetricSpec struct {
	Type     autoscaling.MetricSourceType `json:"type"`
	Object   *ObjectMetricSource          `json:"object,omitempty"`
	Pods     *PodsMetricSource            `json:"pods,omitempty"`
	Resource *ResourceMetricSource        `json:"resource,omitempty"`
	External *ExternalMetricSource        `json:"external,omitempty"`
}

MetricSpec defines which metrics to query from the metrics server

type MetricTarget

type MetricTarget struct {
	Type autoscaling.MetricTargetType `json:"type"`
}

MetricTarget defines the type of metric gathering, either target value, average value, or average utilization of a specific metric

type ObjectMetricSource

type ObjectMetricSource struct {
	DescribedObject autoscaling.CrossVersionObjectReference `json:"describedObject"`
	Metric          autoscaling.MetricIdentifier            `json:"metric"`
	Target          MetricTarget                            `json:"target"`
}

ObjectMetricSource defines gathering metrics for a kubernetes object (for example, hits-per-second on an Ingress object).

type PodsMetricSource

type PodsMetricSource struct {
	Metric autoscaling.MetricIdentifier `json:"metric"`
	Target MetricTarget                 `json:"target"`
}

PodsMetricSource defines gathering metrics describing each pod in the current scale target (for example, transactions-processed-per-second).

type ResourceMetricSource

type ResourceMetricSource struct {
	Name   v1.ResourceName `json:"name" protobuf:"bytes,1,name=name"`
	Target MetricTarget    `json:"target"`
}

ResourceMetricSource defines gathering metrics for a resource metric known to Kubernetes, as specified in requests and limits, describing each pod in the current scale target (e.g. CPU or memory). Such metrics are built in to Kubernetes.