prometheus/discovery/kubernetes/service.go
Paulin Todev 27bb57a37b
Define metric label values in one place
Signed-off-by: Paulin Todev <paulin.todev@gmail.com>
2023-12-11 13:39:01 +00:00

204 lines
5.5 KiB
Go

// Copyright 2016 The Prometheus Authors
// 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 kubernetes
import (
"context"
"errors"
"fmt"
"net"
"strconv"
"github.com/go-kit/log"
"github.com/go-kit/log/level"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/model"
apiv1 "k8s.io/api/core/v1"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/util/workqueue"
"github.com/prometheus/prometheus/discovery/targetgroup"
)
// Service implements discovery of Kubernetes services.
type Service struct {
logger log.Logger
informer cache.SharedInformer
store cache.Store
queue *workqueue.Type
}
// NewService returns a new service discovery.
func NewService(l log.Logger, inf cache.SharedInformer, eventCount *prometheus.CounterVec) *Service {
if l == nil {
l = log.NewNopLogger()
}
svcAddCount := eventCount.WithLabelValues(RoleService.String(), MetricLabelRoleAdd)
svcUpdateCount := eventCount.WithLabelValues(RoleService.String(), MetricLabelRoleUpdate)
svcDeleteCount := eventCount.WithLabelValues(RoleService.String(), MetricLabelRoleDelete)
s := &Service{
logger: l,
informer: inf,
store: inf.GetStore(),
queue: workqueue.NewNamed(RoleService.String()),
}
_, err := s.informer.AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(o interface{}) {
svcAddCount.Inc()
s.enqueue(o)
},
DeleteFunc: func(o interface{}) {
svcDeleteCount.Inc()
s.enqueue(o)
},
UpdateFunc: func(_, o interface{}) {
svcUpdateCount.Inc()
s.enqueue(o)
},
})
if err != nil {
level.Error(l).Log("msg", "Error adding services event handler.", "err", err)
}
return s
}
func (s *Service) enqueue(obj interface{}) {
key, err := cache.DeletionHandlingMetaNamespaceKeyFunc(obj)
if err != nil {
return
}
s.queue.Add(key)
}
// Run implements the Discoverer interface.
func (s *Service) Run(ctx context.Context, ch chan<- []*targetgroup.Group) {
defer s.queue.ShutDown()
if !cache.WaitForCacheSync(ctx.Done(), s.informer.HasSynced) {
if !errors.Is(ctx.Err(), context.Canceled) {
level.Error(s.logger).Log("msg", "service informer unable to sync cache")
}
return
}
go func() {
for s.process(ctx, ch) {
}
}()
// Block until the target provider is explicitly canceled.
<-ctx.Done()
}
func (s *Service) process(ctx context.Context, ch chan<- []*targetgroup.Group) bool {
keyObj, quit := s.queue.Get()
if quit {
return false
}
defer s.queue.Done(keyObj)
key := keyObj.(string)
namespace, name, err := cache.SplitMetaNamespaceKey(key)
if err != nil {
return true
}
o, exists, err := s.store.GetByKey(key)
if err != nil {
return true
}
if !exists {
send(ctx, ch, &targetgroup.Group{Source: serviceSourceFromNamespaceAndName(namespace, name)})
return true
}
eps, err := convertToService(o)
if err != nil {
level.Error(s.logger).Log("msg", "converting to Service object failed", "err", err)
return true
}
send(ctx, ch, s.buildService(eps))
return true
}
func convertToService(o interface{}) (*apiv1.Service, error) {
service, ok := o.(*apiv1.Service)
if ok {
return service, nil
}
return nil, fmt.Errorf("received unexpected object: %v", o)
}
func serviceSource(s *apiv1.Service) string {
return serviceSourceFromNamespaceAndName(s.Namespace, s.Name)
}
func serviceSourceFromNamespaceAndName(namespace, name string) string {
return "svc/" + namespace + "/" + name
}
const (
servicePortNameLabel = metaLabelPrefix + "service_port_name"
servicePortNumberLabel = metaLabelPrefix + "service_port_number"
servicePortProtocolLabel = metaLabelPrefix + "service_port_protocol"
serviceClusterIPLabel = metaLabelPrefix + "service_cluster_ip"
serviceLoadBalancerIP = metaLabelPrefix + "service_loadbalancer_ip"
serviceExternalNameLabel = metaLabelPrefix + "service_external_name"
serviceType = metaLabelPrefix + "service_type"
)
func serviceLabels(svc *apiv1.Service) model.LabelSet {
ls := make(model.LabelSet)
ls[namespaceLabel] = lv(svc.Namespace)
addObjectMetaLabels(ls, svc.ObjectMeta, RoleService)
return ls
}
func (s *Service) buildService(svc *apiv1.Service) *targetgroup.Group {
tg := &targetgroup.Group{
Source: serviceSource(svc),
}
tg.Labels = serviceLabels(svc)
for _, port := range svc.Spec.Ports {
addr := net.JoinHostPort(svc.Name+"."+svc.Namespace+".svc", strconv.FormatInt(int64(port.Port), 10))
labelSet := model.LabelSet{
model.AddressLabel: lv(addr),
servicePortNameLabel: lv(port.Name),
servicePortNumberLabel: lv(strconv.FormatInt(int64(port.Port), 10)),
servicePortProtocolLabel: lv(string(port.Protocol)),
serviceType: lv(string(svc.Spec.Type)),
}
if svc.Spec.Type == apiv1.ServiceTypeExternalName {
labelSet[serviceExternalNameLabel] = lv(svc.Spec.ExternalName)
} else {
labelSet[serviceClusterIPLabel] = lv(svc.Spec.ClusterIP)
}
if svc.Spec.Type == apiv1.ServiceTypeLoadBalancer {
labelSet[serviceLoadBalancerIP] = lv(svc.Spec.LoadBalancerIP)
}
tg.Targets = append(tg.Targets, labelSet)
}
return tg
}