mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-11 14:53:49 +00:00
281 lines
7.9 KiB
Go
281 lines
7.9 KiB
Go
package consulagent
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"errors"
|
|
"flag"
|
|
"fmt"
|
|
"net/url"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discovery/consul"
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape/discoveryutils"
|
|
"github.com/VictoriaMetrics/metrics"
|
|
)
|
|
|
|
// SDCheckInterval is check interval for Consul Agent service discovery.
|
|
var SDCheckInterval = flag.Duration("promscrape.consulagentSDCheckInterval", 30*time.Second, "Interval for checking for changes in Consul Agent. "+
|
|
"This works only if consulagent_sd_configs is configured in '-promscrape.config' file. "+
|
|
"See https://docs.victoriametrics.com/sd_configs.html#consulagent_sd_configs for details")
|
|
|
|
// consulAgentWatcher is a watcher for consul api, updates services map in background with long-polling.
|
|
type consulAgentWatcher struct {
|
|
client *discoveryutils.Client
|
|
|
|
servicesQueryArgs string
|
|
|
|
watchServices []string
|
|
watchDatacenter string
|
|
|
|
// servicesLock protects services
|
|
servicesLock sync.Mutex
|
|
services map[string]*serviceWatcher
|
|
|
|
stoppedCh chan struct{}
|
|
}
|
|
|
|
type serviceWatcher struct {
|
|
serviceName string
|
|
serviceNodes []consul.ServiceNode
|
|
|
|
stoppedCh chan struct{}
|
|
|
|
requestCtx context.Context
|
|
requestCancel context.CancelFunc
|
|
}
|
|
|
|
// newConsulAgentWatcher creates new watcher and starts background service discovery for Consul.
|
|
func newConsulAgentWatcher(client *discoveryutils.Client, sdc *SDConfig, datacenter, namespace string) *consulAgentWatcher {
|
|
var qv = url.Values{}
|
|
if namespace != "" {
|
|
qv.Set("ns", namespace)
|
|
}
|
|
if len(sdc.Filter) > 0 {
|
|
qv.Set("filter", sdc.Filter)
|
|
}
|
|
|
|
cw := &consulAgentWatcher{
|
|
client: client,
|
|
servicesQueryArgs: "?" + qv.Encode(),
|
|
watchServices: sdc.Services,
|
|
watchDatacenter: datacenter,
|
|
services: make(map[string]*serviceWatcher),
|
|
stoppedCh: make(chan struct{}),
|
|
}
|
|
initCh := make(chan struct{})
|
|
go func() {
|
|
cw.watchForServicesUpdates(initCh)
|
|
close(cw.stoppedCh)
|
|
}()
|
|
// wait for initialization to complete
|
|
<-initCh
|
|
return cw
|
|
}
|
|
|
|
func (cw *consulAgentWatcher) mustStop() {
|
|
cw.client.Stop()
|
|
<-cw.stoppedCh
|
|
}
|
|
|
|
func (cw *consulAgentWatcher) updateServices(serviceNames []string) {
|
|
var initWG sync.WaitGroup
|
|
|
|
// Start watchers for new services.
|
|
cw.servicesLock.Lock()
|
|
for _, serviceName := range serviceNames {
|
|
if _, ok := cw.services[serviceName]; ok {
|
|
// The watcher for serviceName already exists.
|
|
continue
|
|
}
|
|
ctx, cancel := context.WithCancel(cw.client.Context())
|
|
sw := &serviceWatcher{
|
|
serviceName: serviceName,
|
|
stoppedCh: make(chan struct{}),
|
|
requestCtx: ctx,
|
|
requestCancel: cancel,
|
|
}
|
|
cw.services[serviceName] = sw
|
|
serviceWatchersCreated.Inc()
|
|
initWG.Add(1)
|
|
go func() {
|
|
serviceWatchersCount.Inc()
|
|
sw.watchForServiceNodesUpdates(cw, &initWG)
|
|
serviceWatchersCount.Dec()
|
|
close(sw.stoppedCh)
|
|
}()
|
|
}
|
|
|
|
// Stop watchers for removed services.
|
|
newServiceNamesMap := make(map[string]struct{}, len(serviceNames))
|
|
for _, serviceName := range serviceNames {
|
|
newServiceNamesMap[serviceName] = struct{}{}
|
|
}
|
|
var swsStopped []*serviceWatcher
|
|
for serviceName, sw := range cw.services {
|
|
if _, ok := newServiceNamesMap[serviceName]; ok {
|
|
continue
|
|
}
|
|
sw.requestCancel()
|
|
delete(cw.services, serviceName)
|
|
swsStopped = append(swsStopped, sw)
|
|
}
|
|
cw.servicesLock.Unlock()
|
|
|
|
// Wait until deleted service watchers are stopped.
|
|
for _, sw := range swsStopped {
|
|
<-sw.stoppedCh
|
|
serviceWatchersStopped.Inc()
|
|
}
|
|
|
|
// Wait until added service watchers are initialized.
|
|
initWG.Wait()
|
|
}
|
|
|
|
// watchForServicesUpdates watches for new services and updates it in cw.
|
|
//
|
|
// watchForServicesUpdates closes the initCh once the initialization is complete and first discovery iteration is done.
|
|
func (cw *consulAgentWatcher) watchForServicesUpdates(initCh chan struct{}) {
|
|
apiServer := cw.client.APIServer()
|
|
f := func() {
|
|
serviceNames, err := cw.getServiceNames()
|
|
if err != nil {
|
|
if !errors.Is(err, context.Canceled) {
|
|
logger.Errorf("cannot obtain Consul Agent services from %q: %s", apiServer, err)
|
|
}
|
|
return
|
|
}
|
|
cw.updateServices(serviceNames)
|
|
}
|
|
|
|
logger.Infof("started Consul Agent service watcher for %q", apiServer)
|
|
f()
|
|
|
|
// send signal that initialization is complete
|
|
close(initCh)
|
|
|
|
ticker := time.NewTicker(getCheckInterval())
|
|
defer ticker.Stop()
|
|
stopCh := cw.client.Context().Done()
|
|
for {
|
|
select {
|
|
case <-ticker.C:
|
|
f()
|
|
case <-stopCh:
|
|
logger.Infof("stopping Consul Agent service watchers for %q", apiServer)
|
|
startTime := time.Now()
|
|
var swsStopped []*serviceWatcher
|
|
|
|
cw.servicesLock.Lock()
|
|
for _, sw := range cw.services {
|
|
sw.requestCancel()
|
|
swsStopped = append(swsStopped, sw)
|
|
}
|
|
cw.servicesLock.Unlock()
|
|
|
|
for _, sw := range swsStopped {
|
|
<-sw.stoppedCh
|
|
serviceWatchersStopped.Inc()
|
|
}
|
|
logger.Infof("stopped Consul Agent service watcher for %q in %.3f seconds", apiServer, time.Since(startTime).Seconds())
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
var (
|
|
serviceWatchersCreated = metrics.NewCounter("vm_promscrape_discovery_consulagent_service_watchers_created_total")
|
|
serviceWatchersStopped = metrics.NewCounter("vm_promscrape_discovery_consulagent_service_watchers_stopped_total")
|
|
serviceWatchersCount = metrics.NewCounter("vm_promscrape_discovery_consulagent_service_watchers")
|
|
)
|
|
|
|
// getServiceNames obtains serviceNames via request to Consul Agent.
|
|
//
|
|
// It returns an empty serviceNames list if response contains the same index.
|
|
func (cw *consulAgentWatcher) getServiceNames() ([]string, error) {
|
|
path := "/v1/agent/services" + cw.servicesQueryArgs
|
|
data, err := cw.client.GetAPIResponse(path)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("cannot perform Consul Agent API request at %q: %w", path, err)
|
|
}
|
|
|
|
var m map[string]consul.Service
|
|
if err := json.Unmarshal(data, &m); err != nil {
|
|
return nil, fmt.Errorf("cannot parse response from %q: %w; data=%q", path, err, data)
|
|
}
|
|
serviceNames := make([]string, 0, len(m))
|
|
for _, service := range m {
|
|
serviceName := service.Service
|
|
if service.Datacenter != cw.watchDatacenter {
|
|
continue
|
|
}
|
|
if !consul.ShouldCollectServiceByName(cw.watchServices, serviceName) {
|
|
continue
|
|
}
|
|
serviceNames = append(serviceNames, serviceName)
|
|
}
|
|
return serviceNames, nil
|
|
}
|
|
|
|
// watchForServiceNodesUpdates watches for Consul serviceNode changes for the given serviceName.
|
|
//
|
|
// watchForServiceNodesUpdates calls initWG.Done() once the initialization is complete and the first discovery iteration is done.
|
|
func (sw *serviceWatcher) watchForServiceNodesUpdates(cw *consulAgentWatcher, initWG *sync.WaitGroup) {
|
|
apiServer := cw.client.APIServer()
|
|
path := "/v1/agent/health/service/name/" + sw.serviceName
|
|
f := func() {
|
|
data, err := cw.client.GetAPIResponseWithParamsCtx(sw.requestCtx, path, nil, nil)
|
|
if err != nil {
|
|
if !errors.Is(err, context.Canceled) {
|
|
logger.Errorf("cannot obtain Consul Agent serviceNodes for serviceName=%q from %q: %s", sw.serviceName, apiServer, err)
|
|
}
|
|
return
|
|
}
|
|
sns, err := consul.ParseServiceNodes(data)
|
|
if err != nil {
|
|
logger.Errorf("cannot parse Consul Agent serviceNodes response for serviceName=%q from %q: %s", sw.serviceName, apiServer, err)
|
|
return
|
|
}
|
|
|
|
cw.servicesLock.Lock()
|
|
sw.serviceNodes = sns
|
|
cw.servicesLock.Unlock()
|
|
}
|
|
|
|
f()
|
|
// Notify caller that initialization is complete
|
|
initWG.Done()
|
|
|
|
ticker := time.NewTicker(getCheckInterval())
|
|
defer ticker.Stop()
|
|
stopCh := sw.requestCtx.Done()
|
|
for {
|
|
select {
|
|
case <-ticker.C:
|
|
f()
|
|
case <-stopCh:
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// getServiceNodesSnapshot returns a snapshot of discovered ServiceNodes.
|
|
func (cw *consulAgentWatcher) getServiceNodesSnapshot() map[string][]consul.ServiceNode {
|
|
cw.servicesLock.Lock()
|
|
sns := make(map[string][]consul.ServiceNode, len(cw.services))
|
|
for svc, sw := range cw.services {
|
|
sns[svc] = sw.serviceNodes
|
|
}
|
|
cw.servicesLock.Unlock()
|
|
return sns
|
|
}
|
|
|
|
func getCheckInterval() time.Duration {
|
|
d := *SDCheckInterval
|
|
if d <= time.Second {
|
|
return time.Second
|
|
}
|
|
return d
|
|
}
|