Example #1
0
// Main manages the startup and shutdown lifecycle of the entire Prometheus server.
func Main() int {
	if err := parse(os.Args[1:]); err != nil {
		log.Error(err)
		return 2
	}

	if cfg.printVersion {
		fmt.Fprintln(os.Stdout, version.Print("prometheus"))
		return 0
	}

	log.Infoln("Starting prometheus", version.Info())
	log.Infoln("Build context", version.BuildContext())

	var reloadables []Reloadable

	var (
		memStorage     = local.NewMemorySeriesStorage(&cfg.storage)
		remoteStorage  = remote.New(&cfg.remote)
		sampleAppender = storage.Fanout{memStorage}
	)
	if remoteStorage != nil {
		sampleAppender = append(sampleAppender, remoteStorage)
		reloadables = append(reloadables, remoteStorage)
	}

	var (
		notifier      = notifier.New(&cfg.notifier)
		targetManager = retrieval.NewTargetManager(sampleAppender)
		queryEngine   = promql.NewEngine(memStorage, &cfg.queryEngine)
	)

	ruleManager := rules.NewManager(&rules.ManagerOptions{
		SampleAppender: sampleAppender,
		Notifier:       notifier,
		QueryEngine:    queryEngine,
		ExternalURL:    cfg.web.ExternalURL,
	})

	flags := map[string]string{}
	cfg.fs.VisitAll(func(f *flag.Flag) {
		flags[f.Name] = f.Value.String()
	})

	version := &web.PrometheusVersion{
		Version:   version.Version,
		Revision:  version.Revision,
		Branch:    version.Branch,
		BuildUser: version.BuildUser,
		BuildDate: version.BuildDate,
		GoVersion: version.GoVersion,
	}

	webHandler := web.New(memStorage, queryEngine, targetManager, ruleManager, version, flags, &cfg.web)

	reloadables = append(reloadables, targetManager, ruleManager, webHandler, notifier)

	if !reloadConfig(cfg.configFile, reloadables...) {
		return 1
	}

	// Wait for reload or termination signals. Start the handler for SIGHUP as
	// early as possible, but ignore it until we are ready to handle reloading
	// our config.
	hup := make(chan os.Signal)
	hupReady := make(chan bool)
	signal.Notify(hup, syscall.SIGHUP)
	go func() {
		<-hupReady
		for {
			select {
			case <-hup:
			case <-webHandler.Reload():
			}
			reloadConfig(cfg.configFile, reloadables...)
		}
	}()

	// Start all components. The order is NOT arbitrary.

	if err := memStorage.Start(); err != nil {
		log.Errorln("Error opening memory series storage:", err)
		return 1
	}
	defer func() {
		if err := memStorage.Stop(); err != nil {
			log.Errorln("Error stopping storage:", err)
		}
	}()

	if remoteStorage != nil {
		prometheus.MustRegister(remoteStorage)

		go remoteStorage.Run()
		defer remoteStorage.Stop()
	}
	// The storage has to be fully initialized before registering.
	prometheus.MustRegister(memStorage)
	prometheus.MustRegister(notifier)
	prometheus.MustRegister(configSuccess)
	prometheus.MustRegister(configSuccessTime)

	// The notifieris a dependency of the rule manager. It has to be
	// started before and torn down afterwards.
	go notifier.Run()
	defer notifier.Stop()

	go ruleManager.Run()
	defer ruleManager.Stop()

	go targetManager.Run()
	defer targetManager.Stop()

	// Shutting down the query engine before the rule manager will cause pending queries
	// to be canceled and ensures a quick shutdown of the rule manager.
	defer queryEngine.Stop()

	go webHandler.Run()

	// Wait for reload or termination signals.
	close(hupReady) // Unblock SIGHUP handler.

	term := make(chan os.Signal)
	signal.Notify(term, os.Interrupt, syscall.SIGTERM)
	select {
	case <-term:
		log.Warn("Received SIGTERM, exiting gracefully...")
	case <-webHandler.Quit():
		log.Warn("Received termination request via web service, exiting gracefully...")
	case err := <-webHandler.ListenError():
		log.Errorln("Error starting web server, exiting gracefully:", err)
	}

	log.Info("See you next time!")
	return 0
}
Example #2
0
// Main manages the startup and shutdown lifecycle of the entire Prometheus server.
func Main() int {
	if err := parse(os.Args[1:]); err != nil {
		log.Error(err)
		return 2
	}

	if cfg.printVersion {
		fmt.Fprintln(os.Stdout, version.Print("prometheus"))
		return 0
	}

	log.Infoln("Starting prometheus", version.Info())
	log.Infoln("Build context", version.BuildContext())

	var (
		sampleAppender = storage.Fanout{}
		reloadables    []Reloadable
	)

	var localStorage local.Storage
	switch cfg.localStorageEngine {
	case "persisted":
		localStorage = local.NewMemorySeriesStorage(&cfg.storage)
		sampleAppender = storage.Fanout{localStorage}
	case "none":
		localStorage = &local.NoopStorage{}
	default:
		log.Errorf("Invalid local storage engine %q", cfg.localStorageEngine)
		return 1
	}

	remoteStorage, err := remote.New(&cfg.remote)
	if err != nil {
		log.Errorf("Error initializing remote storage: %s", err)
		return 1
	}
	if remoteStorage != nil {
		sampleAppender = append(sampleAppender, remoteStorage)
		reloadables = append(reloadables, remoteStorage)
	}

	reloadableRemoteStorage := remote.NewConfigurable()
	sampleAppender = append(sampleAppender, reloadableRemoteStorage)
	reloadables = append(reloadables, reloadableRemoteStorage)

	var (
		notifier       = notifier.New(&cfg.notifier)
		targetManager  = retrieval.NewTargetManager(sampleAppender)
		queryEngine    = promql.NewEngine(localStorage, &cfg.queryEngine)
		ctx, cancelCtx = context.WithCancel(context.Background())
	)

	ruleManager := rules.NewManager(&rules.ManagerOptions{
		SampleAppender: sampleAppender,
		Notifier:       notifier,
		QueryEngine:    queryEngine,
		Context:        ctx,
		ExternalURL:    cfg.web.ExternalURL,
	})

	cfg.web.Context = ctx
	cfg.web.Storage = localStorage
	cfg.web.QueryEngine = queryEngine
	cfg.web.TargetManager = targetManager
	cfg.web.RuleManager = ruleManager

	cfg.web.Version = &web.PrometheusVersion{
		Version:   version.Version,
		Revision:  version.Revision,
		Branch:    version.Branch,
		BuildUser: version.BuildUser,
		BuildDate: version.BuildDate,
		GoVersion: version.GoVersion,
	}

	cfg.web.Flags = map[string]string{}
	cfg.fs.VisitAll(func(f *flag.Flag) {
		cfg.web.Flags[f.Name] = f.Value.String()
	})

	webHandler := web.New(&cfg.web)

	reloadables = append(reloadables, targetManager, ruleManager, webHandler, notifier)

	if err := reloadConfig(cfg.configFile, reloadables...); err != nil {
		log.Errorf("Error loading config: %s", err)
		return 1
	}

	// Wait for reload or termination signals. Start the handler for SIGHUP as
	// early as possible, but ignore it until we are ready to handle reloading
	// our config.
	hup := make(chan os.Signal)
	hupReady := make(chan bool)
	signal.Notify(hup, syscall.SIGHUP)
	go func() {
		<-hupReady
		for {
			select {
			case <-hup:
				if err := reloadConfig(cfg.configFile, reloadables...); err != nil {
					log.Errorf("Error reloading config: %s", err)
				}
			case rc := <-webHandler.Reload():
				if err := reloadConfig(cfg.configFile, reloadables...); err != nil {
					log.Errorf("Error reloading config: %s", err)
					rc <- err
				} else {
					rc <- nil
				}
			}
		}
	}()

	// Start all components. The order is NOT arbitrary.

	if err := localStorage.Start(); err != nil {
		log.Errorln("Error opening memory series storage:", err)
		return 1
	}
	defer func() {
		if err := localStorage.Stop(); err != nil {
			log.Errorln("Error stopping storage:", err)
		}
	}()

	if remoteStorage != nil {
		remoteStorage.Start()
		defer remoteStorage.Stop()
	}

	defer reloadableRemoteStorage.Stop()

	// The storage has to be fully initialized before registering.
	if instrumentedStorage, ok := localStorage.(prometheus.Collector); ok {
		prometheus.MustRegister(instrumentedStorage)
	}
	prometheus.MustRegister(notifier)
	prometheus.MustRegister(configSuccess)
	prometheus.MustRegister(configSuccessTime)

	// The notifier is a dependency of the rule manager. It has to be
	// started before and torn down afterwards.
	go notifier.Run()
	defer notifier.Stop()

	go ruleManager.Run()
	defer ruleManager.Stop()

	go targetManager.Run()
	defer targetManager.Stop()

	// Shutting down the query engine before the rule manager will cause pending queries
	// to be canceled and ensures a quick shutdown of the rule manager.
	defer cancelCtx()

	go webHandler.Run()

	// Wait for reload or termination signals.
	close(hupReady) // Unblock SIGHUP handler.

	term := make(chan os.Signal)
	signal.Notify(term, os.Interrupt, syscall.SIGTERM)
	select {
	case <-term:
		log.Warn("Received SIGTERM, exiting gracefully...")
	case <-webHandler.Quit():
		log.Warn("Received termination request via web service, exiting gracefully...")
	case err := <-webHandler.ListenError():
		log.Errorln("Error starting web server, exiting gracefully:", err)
	}

	log.Info("See you next time!")
	return 0
}