func fetchMetricFamilies(url string, ch chan<- *dto.MetricFamily) {
defer close(ch)
req, err := http.NewRequest("GET", url, nil)
if err != nil {
log.Fatalf("creating GET request for URL %q failed: %s", url, err)
}
req.Header.Add("Accept", acceptHeader)
resp, err := http.DefaultClient.Do(req)
if err != nil {
log.Fatalf("executing GET request for URL %q failed: %s", url, err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
log.Fatalf("GET request for URL %q returned HTTP status %s", url, resp.Status)
}
mediatype, params, err := mime.ParseMediaType(resp.Header.Get("Content-Type"))
if err == nil && mediatype == "application/vnd.google.protobuf" &&
params["encoding"] == "delimited" &&
params["proto"] == "io.prometheus.client.MetricFamily" {
for {
mf := &dto.MetricFamily{}
if _, err = pbutil.ReadDelimited(resp.Body, mf); err != nil {
if err == io.EOF {
break
}
log.Fatalln("reading metric family protocol buffer failed:", err)
}
ch <- mf
}
} else {
// We could do further content-type checks here, but the
// fallback for now will anyway be the text format
// version 0.0.4, so just go for it and see if it works.
var parser expfmt.TextParser
metricFamilies, err := parser.TextToMetricFamilies(resp.Body)
if err != nil {
log.Fatalln("reading text format failed:", err)
}
for _, mf := range metricFamilies {
ch <- mf
}
}
}
func main() {
runtime.GOMAXPROCS(2)
if len(os.Args) != 2 {
log.Fatalf("Usage: %s METRICS_URL", os.Args[0])
}
mfChan := make(chan *dto.MetricFamily, 1024)
go fetchMetricFamilies(os.Args[1], mfChan)
result := []*metricFamily{}
for mf := range mfChan {
result = append(result, newMetricFamily(mf))
}
json, err := json.Marshal(result)
if err != nil {
log.Fatalln("error marshaling JSON:", err)
}
if _, err := os.Stdout.Write(json); err != nil {
log.Fatalln("error writing to stdout:", err)
}
fmt.Println()
}
func main() {
flag.Parse()
if !strings.HasPrefix(*pathPrefix, "/") {
*pathPrefix = "/" + *pathPrefix
}
if !strings.HasSuffix(*pathPrefix, "/") {
*pathPrefix = *pathPrefix + "/"
}
versionInfoTmpl.Execute(os.Stdout, BuildInfo)
conf := config.MustLoadFromFile(*configFile)
silencer := manager.NewSilencer()
defer silencer.Close()
err := silencer.LoadFromFile(*silencesFile)
if err != nil {
log.Warn("Couldn't load silences, starting up with empty silence list: ", err)
}
saveSilencesTicker := time.NewTicker(10 * time.Second)
go func() {
for range saveSilencesTicker.C {
if err := silencer.SaveToFile(*silencesFile); err != nil {
log.Error("Error saving silences to file: ", err)
}
}
}()
defer saveSilencesTicker.Stop()
amURL, err := alertmanagerURL(*hostname, *pathPrefix, *listenAddress, *externalURL)
if err != nil {
log.Fatalln("Error building Alertmanager URL:", err)
}
notifier := manager.NewNotifier(conf.NotificationConfig, amURL)
defer notifier.Close()
inhibitor := new(manager.Inhibitor)
inhibitor.SetInhibitRules(conf.InhibitRules())
options := &manager.MemoryAlertManagerOptions{
Inhibitor: inhibitor,
Silencer: silencer,
Notifier: notifier,
MinRefreshInterval: *minRefreshPeriod,
}
alertManager := manager.NewMemoryAlertManager(options)
alertManager.SetAggregationRules(conf.AggregationRules())
go alertManager.Run()
// Web initialization.
flags := map[string]string{}
flag.VisitAll(func(f *flag.Flag) {
flags[f.Name] = f.Value.String()
})
statusHandler := &web.StatusHandler{
Config: conf.String(),
Flags: flags,
BuildInfo: BuildInfo,
Birth: time.Now(),
PathPrefix: *pathPrefix,
}
webService := &web.WebService{
// REST API Service.
AlertManagerService: &api.AlertManagerService{
Manager: alertManager,
Silencer: silencer,
PathPrefix: *pathPrefix,
},
// Template-based page handlers.
AlertsHandler: &web.AlertsHandler{
Manager: alertManager,
IsSilencedInterrogator: silencer,
PathPrefix: *pathPrefix,
},
SilencesHandler: &web.SilencesHandler{
Silencer: silencer,
PathPrefix: *pathPrefix,
},
StatusHandler: statusHandler,
}
go webService.ServeForever(*listenAddress, *pathPrefix)
// React to configuration changes.
watcher := config.NewFileWatcher(*configFile)
go watcher.Watch(func(conf *config.Config) {
inhibitor.SetInhibitRules(conf.InhibitRules())
notifier.SetNotificationConfigs(conf.NotificationConfig)
alertManager.SetAggregationRules(conf.AggregationRules())
statusHandler.UpdateConfig(conf.String())
})
log.Info("Running notification dispatcher...")
notifier.Dispatch()
}