mirror of
https://github.com/prometheus/prometheus.git
synced 2024-11-10 07:34:04 -08:00
367 lines
10 KiB
Go
367 lines
10 KiB
Go
// Copyright 2016 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package kubernetes
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import (
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"encoding/json"
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"fmt"
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"io/ioutil"
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"net"
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"net/http"
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"sync"
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"time"
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"github.com/prometheus/common/log"
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"github.com/prometheus/common/model"
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"github.com/prometheus/prometheus/config"
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"github.com/prometheus/prometheus/util/strutil"
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"golang.org/x/net/context"
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)
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type serviceDiscovery struct {
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mtx sync.RWMutex
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services map[string]map[string]*Service
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retryInterval time.Duration
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kd *Discovery
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}
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func (d *serviceDiscovery) run(ctx context.Context, ch chan<- []*config.TargetGroup) {
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update := make(chan interface{}, 10)
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go d.startServiceWatch(update, ctx.Done(), d.retryInterval)
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for {
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tgs := []*config.TargetGroup{}
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select {
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case <-ctx.Done():
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return
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case event := <-update:
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switch e := event.(type) {
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case *endpointsEvent:
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log.Debugf("k8s discovery received endpoint event (EventType=%s, Endpoint Name=%s)", e.EventType, e.Endpoints.ObjectMeta.Name)
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tgs = append(tgs, d.updateServiceEndpoints(e.Endpoints, e.EventType))
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case *serviceEvent:
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log.Debugf("k8s discovery received service event (EventType=%s, Service Name=%s)", e.EventType, e.Service.ObjectMeta.Name)
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tgs = append(tgs, d.updateService(e.Service, e.EventType))
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}
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}
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if tgs == nil {
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continue
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}
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for _, tg := range tgs {
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select {
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case ch <- []*config.TargetGroup{tg}:
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case <-ctx.Done():
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return
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}
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}
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}
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}
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func (d *serviceDiscovery) getServices() (map[string]map[string]*Service, string, error) {
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res, err := d.kd.queryAPIServerPath(servicesURL)
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if err != nil {
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// If we can't list services then we can't watch them. Assume this is a misconfiguration
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// & return error.
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return nil, "", fmt.Errorf("unable to list Kubernetes services: %s", err)
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}
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defer res.Body.Close()
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if res.StatusCode != http.StatusOK {
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return nil, "", fmt.Errorf("unable to list Kubernetes services; unexpected response: %d %s", res.StatusCode, res.Status)
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}
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var services ServiceList
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if err := json.NewDecoder(res.Body).Decode(&services); err != nil {
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body, _ := ioutil.ReadAll(res.Body)
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return nil, "", fmt.Errorf("unable to list Kubernetes services; unexpected response body: %s", string(body))
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}
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serviceMap := map[string]map[string]*Service{}
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for idx, service := range services.Items {
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namespace, ok := serviceMap[service.ObjectMeta.Namespace]
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if !ok {
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namespace = map[string]*Service{}
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serviceMap[service.ObjectMeta.Namespace] = namespace
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}
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namespace[service.ObjectMeta.Name] = &services.Items[idx]
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}
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return serviceMap, services.ResourceVersion, nil
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}
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// watchServices watches services as they come & go.
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func (d *serviceDiscovery) startServiceWatch(events chan<- interface{}, done <-chan struct{}, retryInterval time.Duration) {
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until(func() {
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// We use separate target groups for each discovered service so we'll need to clean up any if they've been deleted
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// in Kubernetes while we couldn't connect - small chance of this, but worth dealing with.
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d.mtx.Lock()
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existingServices := d.services
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// Reset the known services.
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d.services = map[string]map[string]*Service{}
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d.mtx.Unlock()
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services, resourceVersion, err := d.getServices()
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if err != nil {
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log.Errorf("Cannot initialize services collection: %s", err)
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return
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}
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// Now let's loop through the old services & see if they still exist in here
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for oldNSName, oldNS := range existingServices {
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if ns, ok := services[oldNSName]; !ok {
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for _, service := range existingServices[oldNSName] {
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events <- &serviceEvent{Deleted, service}
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}
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} else {
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for oldServiceName, oldService := range oldNS {
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if _, ok := ns[oldServiceName]; !ok {
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events <- &serviceEvent{Deleted, oldService}
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}
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}
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}
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}
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// Discard the existing services map for GC.
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existingServices = nil
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for _, ns := range services {
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for _, service := range ns {
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events <- &serviceEvent{Added, service}
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}
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}
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var wg sync.WaitGroup
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wg.Add(2)
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go func() {
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d.watchServices(resourceVersion, events, done)
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wg.Done()
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}()
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go func() {
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d.watchServiceEndpoints(resourceVersion, events, done)
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wg.Done()
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}()
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wg.Wait()
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}, retryInterval, done)
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}
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func (d *serviceDiscovery) watchServices(resourceVersion string, events chan<- interface{}, done <-chan struct{}) {
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req, err := http.NewRequest("GET", servicesURL, nil)
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if err != nil {
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log.Errorf("Failed to create services request: %s", err)
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return
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}
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values := req.URL.Query()
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values.Add("watch", "true")
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values.Add("resourceVersion", resourceVersion)
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req.URL.RawQuery = values.Encode()
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res, err := d.kd.queryAPIServerReq(req)
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if err != nil {
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log.Errorf("Failed to watch services: %s", err)
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return
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}
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defer res.Body.Close()
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if res.StatusCode != http.StatusOK {
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log.Errorf("Failed to watch services: %d", res.StatusCode)
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return
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}
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dec := json.NewDecoder(res.Body)
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for {
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var event serviceEvent
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if err := dec.Decode(&event); err != nil {
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log.Errorf("Watch services unexpectedly closed: %s", err)
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return
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}
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select {
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case events <- &event:
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case <-done:
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return
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}
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}
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}
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// watchServiceEndpoints watches service endpoints as they come & go.
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func (d *serviceDiscovery) watchServiceEndpoints(resourceVersion string, events chan<- interface{}, done <-chan struct{}) {
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req, err := http.NewRequest("GET", endpointsURL, nil)
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if err != nil {
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log.Errorf("Failed to create service endpoints request: %s", err)
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return
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}
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values := req.URL.Query()
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values.Add("watch", "true")
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values.Add("resourceVersion", resourceVersion)
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req.URL.RawQuery = values.Encode()
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res, err := d.kd.queryAPIServerReq(req)
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if err != nil {
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log.Errorf("Failed to watch service endpoints: %s", err)
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return
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}
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defer res.Body.Close()
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if res.StatusCode != http.StatusOK {
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log.Errorf("Failed to watch service endpoints: %d", res.StatusCode)
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return
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}
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dec := json.NewDecoder(res.Body)
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for {
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var event endpointsEvent
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if err := dec.Decode(&event); err != nil {
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log.Errorf("Watch service endpoints unexpectedly closed: %s", err)
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return
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}
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select {
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case events <- &event:
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case <-done:
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}
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}
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}
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func (d *serviceDiscovery) updateService(service *Service, eventType EventType) *config.TargetGroup {
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d.mtx.Lock()
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defer d.mtx.Unlock()
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switch eventType {
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case Deleted:
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return d.deleteService(service)
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case Added, Modified:
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return d.addService(service)
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}
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return nil
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}
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func (d *serviceDiscovery) deleteService(service *Service) *config.TargetGroup {
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tg := &config.TargetGroup{Source: serviceSource(service)}
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delete(d.services[service.ObjectMeta.Namespace], service.ObjectMeta.Name)
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if len(d.services[service.ObjectMeta.Namespace]) == 0 {
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delete(d.services, service.ObjectMeta.Namespace)
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}
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return tg
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}
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func (d *serviceDiscovery) addService(service *Service) *config.TargetGroup {
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namespace, ok := d.services[service.ObjectMeta.Namespace]
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if !ok {
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namespace = map[string]*Service{}
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d.services[service.ObjectMeta.Namespace] = namespace
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}
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namespace[service.ObjectMeta.Name] = service
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endpointURL := fmt.Sprintf(serviceEndpointsURL, service.ObjectMeta.Namespace, service.ObjectMeta.Name)
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res, err := d.kd.queryAPIServerPath(endpointURL)
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if err != nil {
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log.Errorf("Error getting service endpoints: %s", err)
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return nil
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}
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defer res.Body.Close()
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if res.StatusCode != http.StatusOK {
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log.Errorf("Failed to get service endpoints: %d", res.StatusCode)
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return nil
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}
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var eps Endpoints
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if err := json.NewDecoder(res.Body).Decode(&eps); err != nil {
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log.Errorf("Error getting service endpoints: %s", err)
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return nil
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}
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return d.updateServiceTargetGroup(service, &eps)
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}
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func (d *serviceDiscovery) updateServiceTargetGroup(service *Service, eps *Endpoints) *config.TargetGroup {
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tg := &config.TargetGroup{
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Source: serviceSource(service),
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Labels: model.LabelSet{
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serviceNamespaceLabel: model.LabelValue(service.ObjectMeta.Namespace),
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serviceNameLabel: model.LabelValue(service.ObjectMeta.Name),
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},
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}
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for k, v := range service.ObjectMeta.Labels {
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labelName := strutil.SanitizeLabelName(serviceLabelPrefix + k)
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tg.Labels[model.LabelName(labelName)] = model.LabelValue(v)
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}
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for k, v := range service.ObjectMeta.Annotations {
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labelName := strutil.SanitizeLabelName(serviceAnnotationPrefix + k)
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tg.Labels[model.LabelName(labelName)] = model.LabelValue(v)
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}
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serviceAddress := service.ObjectMeta.Name + "." + service.ObjectMeta.Namespace + ".svc"
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// Append the first TCP service port if one exists.
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for _, port := range service.Spec.Ports {
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if port.Protocol == ProtocolTCP {
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serviceAddress += fmt.Sprintf(":%d", port.Port)
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break
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}
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}
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t := model.LabelSet{
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model.AddressLabel: model.LabelValue(serviceAddress),
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roleLabel: model.LabelValue("service"),
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}
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tg.Targets = append(tg.Targets, t)
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// Now let's loop through the endpoints & add them to the target group with appropriate labels.
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for _, ss := range eps.Subsets {
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epPort := ss.Ports[0].Port
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for _, addr := range ss.Addresses {
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ipAddr := addr.IP
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if len(ipAddr) == net.IPv6len {
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ipAddr = "[" + ipAddr + "]"
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}
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address := fmt.Sprintf("%s:%d", ipAddr, epPort)
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t := model.LabelSet{
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model.AddressLabel: model.LabelValue(address),
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roleLabel: model.LabelValue("endpoint"),
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}
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tg.Targets = append(tg.Targets, t)
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}
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}
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return tg
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}
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func (d *serviceDiscovery) updateServiceEndpoints(endpoints *Endpoints, eventType EventType) *config.TargetGroup {
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d.mtx.Lock()
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defer d.mtx.Unlock()
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serviceNamespace := endpoints.ObjectMeta.Namespace
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serviceName := endpoints.ObjectMeta.Name
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if service, ok := d.services[serviceNamespace][serviceName]; ok {
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return d.updateServiceTargetGroup(service, endpoints)
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}
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return nil
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}
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func serviceSource(service *Service) string {
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return sourceServicePrefix + ":" + service.ObjectMeta.Namespace + "/" + service.ObjectMeta.Name
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}
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