prometheus/discovery/kubernetes/endpoints.go

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// 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
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import (
"fmt"
"net"
"strconv"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/common/log"
"github.com/prometheus/common/model"
"golang.org/x/net/context"
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apiv1 "k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/cache"
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)
// Endpoints discovers new endpoint targets.
type Endpoints struct {
logger log.Logger
endpointsInf cache.SharedInformer
serviceInf cache.SharedInformer
podInf cache.SharedInformer
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podStore cache.Store
endpointsStore cache.Store
serviceStore cache.Store
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}
// NewEndpoints returns a new endpoints discovery.
func NewEndpoints(l log.Logger, svc, eps, pod cache.SharedInformer) *Endpoints {
ep := &Endpoints{
logger: l,
endpointsInf: eps,
endpointsStore: eps.GetStore(),
serviceInf: svc,
serviceStore: svc.GetStore(),
podInf: pod,
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podStore: pod.GetStore(),
}
return ep
}
// Run implements the retrieval.TargetProvider interface.
func (e *Endpoints) Run(ctx context.Context, ch chan<- []*config.TargetGroup) {
// Send full initial set of endpoint targets.
var initial []*config.TargetGroup
for _, o := range e.endpointsStore.List() {
tg := e.buildEndpoints(o.(*apiv1.Endpoints))
initial = append(initial, tg)
}
select {
case <-ctx.Done():
return
case ch <- initial:
}
// Send target groups for pod updates.
send := func(tg *config.TargetGroup) {
if tg == nil {
return
}
e.logger.With("tg", fmt.Sprintf("%#v", tg)).Debugln("endpoints update")
select {
case <-ctx.Done():
case ch <- []*config.TargetGroup{tg}:
}
}
e.endpointsInf.AddEventHandler(cache.ResourceEventHandlerFuncs{
AddFunc: func(o interface{}) {
eventCount.WithLabelValues("endpoints", "add").Inc()
eps, err := convertToEndpoints(o)
if err != nil {
e.logger.With("err", err).Errorln("converting to Endpoints object failed")
return
}
send(e.buildEndpoints(eps))
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},
UpdateFunc: func(_, o interface{}) {
eventCount.WithLabelValues("endpoints", "update").Inc()
eps, err := convertToEndpoints(o)
if err != nil {
e.logger.With("err", err).Errorln("converting to Endpoints object failed")
return
}
send(e.buildEndpoints(eps))
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},
DeleteFunc: func(o interface{}) {
eventCount.WithLabelValues("endpoints", "delete").Inc()
eps, err := convertToEndpoints(o)
if err != nil {
e.logger.With("err", err).Errorln("converting to Endpoints object failed")
return
}
send(&config.TargetGroup{Source: endpointsSource(eps)})
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},
})
serviceUpdate := func(o interface{}) {
svc, err := convertToService(o)
if err != nil {
e.logger.With("err", err).Errorln("converting to Service object failed")
return
}
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ep := &apiv1.Endpoints{}
ep.Namespace = svc.Namespace
ep.Name = svc.Name
obj, exists, err := e.endpointsStore.Get(ep)
if exists && err != nil {
send(e.buildEndpoints(obj.(*apiv1.Endpoints)))
}
if err != nil {
e.logger.With("err", err).Errorln("retrieving endpoints failed")
}
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}
e.serviceInf.AddEventHandler(cache.ResourceEventHandlerFuncs{
// TODO(fabxc): potentially remove add and delete event handlers. Those should
// be triggered via the endpoint handlers already.
AddFunc: func(o interface{}) {
eventCount.WithLabelValues("service", "add").Inc()
serviceUpdate(o)
},
UpdateFunc: func(_, o interface{}) {
eventCount.WithLabelValues("service", "update").Inc()
serviceUpdate(o)
},
DeleteFunc: func(o interface{}) {
eventCount.WithLabelValues("service", "delete").Inc()
serviceUpdate(o)
},
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})
// Block until the target provider is explicitly canceled.
<-ctx.Done()
}
func convertToEndpoints(o interface{}) (*apiv1.Endpoints, error) {
endpoints, isEndpoints := o.(*apiv1.Endpoints)
if !isEndpoints {
deletedState, ok := o.(cache.DeletedFinalStateUnknown)
if !ok {
return nil, fmt.Errorf("Received unexpected object: %v", o)
}
endpoints, ok = deletedState.Obj.(*apiv1.Endpoints)
if !ok {
return nil, fmt.Errorf("DeletedFinalStateUnknown contained non-Endpoints object: %v", deletedState.Obj)
}
}
return endpoints, nil
}
func endpointsSource(ep *apiv1.Endpoints) string {
return "endpoints/" + ep.ObjectMeta.Namespace + "/" + ep.ObjectMeta.Name
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}
const (
endpointsNameLabel = metaLabelPrefix + "endpoints_name"
endpointReadyLabel = metaLabelPrefix + "endpoint_ready"
endpointPortNameLabel = metaLabelPrefix + "endpoint_port_name"
endpointPortProtocolLabel = metaLabelPrefix + "endpoint_port_protocol"
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)
func (e *Endpoints) buildEndpoints(eps *apiv1.Endpoints) *config.TargetGroup {
if len(eps.Subsets) == 0 {
return nil
}
tg := &config.TargetGroup{
Source: endpointsSource(eps),
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}
tg.Labels = model.LabelSet{
namespaceLabel: lv(eps.Namespace),
endpointsNameLabel: lv(eps.Name),
}
e.addServiceLabels(eps.Namespace, eps.Name, tg)
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type podEntry struct {
pod *apiv1.Pod
servicePorts []apiv1.EndpointPort
}
seenPods := map[string]*podEntry{}
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add := func(addr apiv1.EndpointAddress, port apiv1.EndpointPort, ready string) {
a := net.JoinHostPort(addr.IP, strconv.FormatUint(uint64(port.Port), 10))
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target := model.LabelSet{
model.AddressLabel: lv(a),
endpointPortNameLabel: lv(port.Name),
endpointPortProtocolLabel: lv(string(port.Protocol)),
endpointReadyLabel: lv(ready),
}
pod := e.resolvePodRef(addr.TargetRef)
if pod == nil {
// This target is not a Pod, so don't continue with Pod specific logic.
tg.Targets = append(tg.Targets, target)
return
}
s := pod.Namespace + "/" + pod.Name
sp, ok := seenPods[s]
if !ok {
sp = &podEntry{pod: pod}
seenPods[s] = sp
}
// Attach standard pod labels.
target = target.Merge(podLabels(pod))
// Attach potential container port labels matching the endpoint port.
for _, c := range pod.Spec.Containers {
for _, cport := range c.Ports {
if port.Port == cport.ContainerPort {
ports := strconv.FormatUint(uint64(port.Port), 10)
target[podContainerNameLabel] = lv(c.Name)
target[podContainerPortNameLabel] = lv(cport.Name)
target[podContainerPortNumberLabel] = lv(ports)
target[podContainerPortProtocolLabel] = lv(string(port.Protocol))
break
}
}
}
// Add service port so we know that we have already generated a target
// for it.
sp.servicePorts = append(sp.servicePorts, port)
tg.Targets = append(tg.Targets, target)
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}
for _, ss := range eps.Subsets {
for _, port := range ss.Ports {
for _, addr := range ss.Addresses {
add(addr, port, "true")
}
// Although this generates the same target again, as it was generated in
// the loop above, it causes the ready meta label to be overridden.
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for _, addr := range ss.NotReadyAddresses {
add(addr, port, "false")
}
}
}
// For all seen pods, check all container ports. If they were not covered
// by one of the service endpoints, generate targets for them.
for _, pe := range seenPods {
for _, c := range pe.pod.Spec.Containers {
for _, cport := range c.Ports {
hasSeenPort := func() bool {
for _, eport := range pe.servicePorts {
if cport.ContainerPort == eport.Port {
return true
}
}
return false
}
if hasSeenPort() {
continue
}
a := net.JoinHostPort(pe.pod.Status.PodIP, strconv.FormatUint(uint64(cport.ContainerPort), 10))
ports := strconv.FormatUint(uint64(cport.ContainerPort), 10)
target := model.LabelSet{
model.AddressLabel: lv(a),
podContainerNameLabel: lv(c.Name),
podContainerPortNameLabel: lv(cport.Name),
podContainerPortNumberLabel: lv(ports),
podContainerPortProtocolLabel: lv(string(cport.Protocol)),
}
tg.Targets = append(tg.Targets, target.Merge(podLabels(pe.pod)))
}
}
}
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return tg
}
func (e *Endpoints) resolvePodRef(ref *apiv1.ObjectReference) *apiv1.Pod {
if ref == nil || ref.Kind != "Pod" {
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return nil
}
p := &apiv1.Pod{}
p.Namespace = ref.Namespace
p.Name = ref.Name
obj, exists, err := e.podStore.Get(p)
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if err != nil || !exists {
return nil
}
if err != nil {
e.logger.With("err", err).Errorln("resolving pod ref failed")
}
return obj.(*apiv1.Pod)
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}
func (e *Endpoints) addServiceLabels(ns, name string, tg *config.TargetGroup) {
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svc := &apiv1.Service{}
svc.Namespace = ns
svc.Name = name
obj, exists, err := e.serviceStore.Get(svc)
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if !exists || err != nil {
return
}
if err != nil {
e.logger.With("err", err).Errorln("retrieving service failed")
}
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svc = obj.(*apiv1.Service)
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tg.Labels = tg.Labels.Merge(serviceLabels(svc))
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}