endpointslice.go

/*
Copyright 2022 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 store

import (
	"context"
	"strconv"

	basemetrics "k8s.io/component-base/metrics"

	"k8s.io/kube-state-metrics/v2/pkg/metric"
	generator "k8s.io/kube-state-metrics/v2/pkg/metric_generator"

	discoveryv1 "k8s.io/api/discovery/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/watch"
	clientset "k8s.io/client-go/kubernetes"
	"k8s.io/client-go/tools/cache"
)

var (
	descEndpointSliceAnnotationsName     = "kube_endpointslice_annotations"
	descEndpointSliceAnnotationsHelp     = "Kubernetes annotations converted to Prometheus labels."
	descEndpointSliceLabelsName          = "kube_endpointslice_labels"
	descEndpointSliceLabelsHelp          = "Kubernetes labels converted to Prometheus labels."
	descEndpointSliceLabelsDefaultLabels = []string{"endpointslice", "namespace"}
)

func endpointSliceMetricFamilies(allowAnnotationsList, allowLabelsList []string) []generator.FamilyGenerator {
	return []generator.FamilyGenerator{
		*generator.NewFamilyGeneratorWithStability(
			"kube_endpointslice_info",
			"Information about endpointslice.",
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(s *discoveryv1.EndpointSlice) *metric.Family {

				m := metric.Metric{
					LabelKeys:   []string{"addresstype"},
					LabelValues: []string{string(s.AddressType)},
					Value:       1,
				}
				return &metric.Family{Metrics: []*metric.Metric{&m}}
			}),
		),
		*generator.NewFamilyGeneratorWithStability(
			"kube_endpointslice_created",
			"Unix creation timestamp",
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(s *discoveryv1.EndpointSlice) *metric.Family {
				ms := []*metric.Metric{}
				if !s.CreationTimestamp.IsZero() {
					ms = append(ms, &metric.Metric{
						Value: float64(s.CreationTimestamp.Unix()),
					})
				}
				return &metric.Family{
					Metrics: ms,
				}
			}),
		),
		*generator.NewFamilyGeneratorWithStability(
			"kube_endpointslice_endpoints_hints",
			"Topology routing hints attached to endpoints",
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(e *discoveryv1.EndpointSlice) *metric.Family {
				m := []*metric.Metric{}
				for _, ep := range e.Endpoints {
					// Hint is populated when the endpoint is configured to be zone aware and preferentially route requests to its local zone.
					// If there is no hint, skip this metric
					if ep.Hints != nil && len(ep.Hints.ForZones) > 0 {
						var (
							labelKeys,
							labelValues []string
						)

						// Per Docs.
						// This must contain at least one address but no more than
						// 100. These are all assumed to be fungible and clients may choose to only
						// use the first element. Refer to: https://issue.k8s.io/106267
						labelKeys = append(labelKeys, "address")
						labelValues = append(labelValues, ep.Addresses[0])

						for _, zone := range ep.Hints.ForZones {
							m = append(m, &metric.Metric{
								LabelKeys:   append(labelKeys, "for_zone"),
								LabelValues: append(labelValues, zone.Name),
								Value:       1,
							})
						}
					}
				}
				return &metric.Family{
					Metrics: m,
				}
			}),
		),
		*generator.NewFamilyGeneratorWithStability(
			"kube_endpointslice_endpoints",
			"Endpoints attached to the endpointslice.",
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(e *discoveryv1.EndpointSlice) *metric.Family {
				m := []*metric.Metric{}
				for _, ep := range e.Endpoints {
					var (
						labelKeys,
						labelValues []string
					)

					if ep.Conditions.Ready != nil {
						labelKeys = append(labelKeys, "ready")
						labelValues = append(labelValues, strconv.FormatBool(*ep.Conditions.Ready))
					}
					if ep.Conditions.Serving != nil {
						labelKeys = append(labelKeys, "serving")
						labelValues = append(labelValues, strconv.FormatBool(*ep.Conditions.Serving))
					}
					if ep.Conditions.Terminating != nil {
						labelKeys = append(labelKeys, "terminating")
						labelValues = append(labelValues, strconv.FormatBool(*ep.Conditions.Terminating))
					}

					if ep.Hostname != nil {
						labelKeys = append(labelKeys, "hostname")
						labelValues = append(labelValues, *ep.Hostname)
					}

					if ep.TargetRef != nil {
						if ep.TargetRef.Kind != "" {
							labelKeys = append(labelKeys, "targetref_kind")
							labelValues = append(labelValues, ep.TargetRef.Kind)
						}
						if ep.TargetRef.Name != "" {
							labelKeys = append(labelKeys, "targetref_name")
							labelValues = append(labelValues, ep.TargetRef.Name)
						}
						if ep.TargetRef.Namespace != "" {
							labelKeys = append(labelKeys, "targetref_namespace")
							labelValues = append(labelValues, ep.TargetRef.Namespace)
						}
					}

					if ep.NodeName != nil {
						labelKeys = append(labelKeys, "endpoint_nodename")
						labelValues = append(labelValues, *ep.NodeName)
					}

					if ep.Zone != nil {
						labelKeys = append(labelKeys, "endpoint_zone")
						labelValues = append(labelValues, *ep.Zone)
					}
					labelKeys = append(labelKeys, "address")
					for _, address := range ep.Addresses {
						newlabelValues := make([]string, len(labelValues))
						copy(newlabelValues, labelValues)
						newlabelValues = append(newlabelValues, address)

						m = append(m, &metric.Metric{
							LabelKeys:   labelKeys,
							LabelValues: newlabelValues,
							Value:       1,
						})
					}
				}
				return &metric.Family{
					Metrics: m,
				}
			}),
		),

		*generator.NewFamilyGeneratorWithStability(
			"kube_endpointslice_ports",
			"Ports attached to the endpointslice.",
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(e *discoveryv1.EndpointSlice) *metric.Family {
				m := []*metric.Metric{}
				for _, port := range e.Ports {
					m = append(m, &metric.Metric{
						LabelValues: []string{*port.Name, string(*port.Protocol), strconv.FormatInt(int64(*port.Port), 10)},
						LabelKeys:   []string{"port_name", "port_protocol", "port_number"},
						Value:       1,
					})
				}
				return &metric.Family{
					Metrics: m,
				}
			}),
		),
		*generator.NewFamilyGeneratorWithStability(
			descEndpointSliceAnnotationsName,
			descEndpointSliceAnnotationsHelp,
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(s *discoveryv1.EndpointSlice) *metric.Family {
				if len(allowAnnotationsList) == 0 {
					return &metric.Family{}
				}
				annotationKeys, annotationValues := createPrometheusLabelKeysValues("annotation", s.Annotations, allowAnnotationsList)
				return &metric.Family{
					Metrics: []*metric.Metric{
						{
							LabelKeys:   annotationKeys,
							LabelValues: annotationValues,
							Value:       1,
						},
					},
				}
			}),
		),
		*generator.NewFamilyGeneratorWithStability(
			descEndpointSliceLabelsName,
			descEndpointSliceLabelsHelp,
			metric.Gauge,
			basemetrics.ALPHA,
			"",
			wrapEndpointSliceFunc(func(s *discoveryv1.EndpointSlice) *metric.Family {
				if len(allowLabelsList) == 0 {
					return &metric.Family{}
				}
				labelKeys, labelValues := createPrometheusLabelKeysValues("label", s.Labels, allowLabelsList)
				return &metric.Family{
					Metrics: []*metric.Metric{
						{
							LabelKeys:   labelKeys,
							LabelValues: labelValues,
							Value:       1,
						},
					},
				}
			}),
		),
	}
}

func wrapEndpointSliceFunc(f func(*discoveryv1.EndpointSlice) *metric.Family) func(interface{}) *metric.Family {
	return func(obj interface{}) *metric.Family {
		endpointSlice := obj.(*discoveryv1.EndpointSlice)

		metricFamily := f(endpointSlice)

		for _, m := range metricFamily.Metrics {
			m.LabelKeys, m.LabelValues = mergeKeyValues(descEndpointSliceLabelsDefaultLabels, []string{endpointSlice.Name, endpointSlice.Namespace}, m.LabelKeys, m.LabelValues)
		}

		return metricFamily
	}
}

func createEndpointSliceListWatch(kubeClient clientset.Interface, ns string, fieldSelector string) cache.ListerWatcher {
	return &cache.ListWatch{
		ListFunc: func(opts metav1.ListOptions) (runtime.Object, error) {
			opts.FieldSelector = fieldSelector
			return kubeClient.DiscoveryV1().EndpointSlices(ns).List(context.TODO(), opts)
		},
		WatchFunc: func(opts metav1.ListOptions) (watch.Interface, error) {
			opts.FieldSelector = fieldSelector
			return kubeClient.DiscoveryV1().EndpointSlices(ns).Watch(context.TODO(), opts)
		},
	}
}