func runAgent()

in cmd/telegraf/telegraf.go [205:329]
102 lines of code
37 McCabe index (conditional complexity)

func runAgent(ctx context.Context,
	inputFilters []string,
	outputFilters []string,
) error {
	// If no other options are specified, load the config file and run.
	c := config.NewConfig()
	c.OutputFilters = outputFilters
	c.InputFilters = inputFilters
	var err error
	// providing no "config" flag should load default config
	if len(fConfigs) == 0 {
		err = c.LoadConfig("")
		if err != nil {
			return err
		}
	}
	for _, fConfig := range fConfigs {
		err = c.LoadConfig(fConfig)
		if err != nil {
			return err
		}
	}

	for _, fConfigDirectory := range fConfigDirs {
		err = c.LoadDirectory(fConfigDirectory)
		if err != nil {
			return err
		}
	}

	if !*fTest && len(c.Outputs) == 0 {
		return errors.New("Error: no outputs found, did you provide a valid config file?")
	}
	if *fPlugins == "" && len(c.Inputs) == 0 {
		return errors.New("Error: no inputs found, did you provide a valid config file?")
	}

	if int64(c.Agent.Interval) <= 0 {
		return fmt.Errorf("Agent interval must be positive, found %v", c.Agent.Interval)
	}

	if int64(c.Agent.FlushInterval) <= 0 {
		return fmt.Errorf("Agent flush_interval must be positive; found %v", c.Agent.Interval)
	}

	// Setup logging as configured.
	telegraf.Debug = c.Agent.Debug || *fDebug
	logConfig := logger.LogConfig{
		Debug:               telegraf.Debug,
		Quiet:               c.Agent.Quiet || *fQuiet,
		LogTarget:           c.Agent.LogTarget,
		Logfile:             c.Agent.Logfile,
		RotationInterval:    c.Agent.LogfileRotationInterval,
		RotationMaxSize:     c.Agent.LogfileRotationMaxSize,
		RotationMaxArchives: c.Agent.LogfileRotationMaxArchives,
		LogWithTimezone:     c.Agent.LogWithTimezone,
	}

	logger.SetupLogging(logConfig)

	log.Printf("I! Starting Telegraf %s", version)
	log.Printf("I! Loaded inputs: %s", strings.Join(c.InputNames(), " "))
	log.Printf("I! Loaded aggregators: %s", strings.Join(c.AggregatorNames(), " "))
	log.Printf("I! Loaded processors: %s", strings.Join(c.ProcessorNames(), " "))
	if !*fRunOnce && (*fTest || *fTestWait != 0) {
		log.Print("W! " + color.RedString("Outputs are not used in testing mode!"))
	} else {
		log.Printf("I! Loaded outputs: %s", strings.Join(c.OutputNames(), " "))
	}
	log.Printf("I! Tags enabled: %s", c.ListTags())

	if count, found := c.Deprecations["inputs"]; found && (count[0] > 0 || count[1] > 0) {
		log.Printf("W! Deprecated inputs: %d and %d options", count[0], count[1])
	}
	if count, found := c.Deprecations["aggregators"]; found && (count[0] > 0 || count[1] > 0) {
		log.Printf("W! Deprecated aggregators: %d and %d options", count[0], count[1])
	}
	if count, found := c.Deprecations["processors"]; found && (count[0] > 0 || count[1] > 0) {
		log.Printf("W! Deprecated processors: %d and %d options", count[0], count[1])
	}
	if count, found := c.Deprecations["outputs"]; found && (count[0] > 0 || count[1] > 0) {
		log.Printf("W! Deprecated outputs: %d and %d options", count[0], count[1])
	}

	ag, err := agent.NewAgent(c)
	if err != nil {
		return err
	}

	// Notify systemd that telegraf is ready
	// SdNotify() only tries to notify if the NOTIFY_SOCKET environment is set, so it's safe to call when systemd isn't present.
	// Ignore the return values here because they're not valid for platforms that don't use systemd.
	// For platforms that use systemd, telegraf doesn't log if the notification failed.
	_, _ = daemon.SdNotify(false, daemon.SdNotifyReady)

	if *fRunOnce {
		wait := time.Duration(*fTestWait) * time.Second
		return ag.Once(ctx, wait)
	}

	if *fTest || *fTestWait != 0 {
		wait := time.Duration(*fTestWait) * time.Second
		return ag.Test(ctx, wait)
	}

	if *fPidfile != "" {
		f, err := os.OpenFile(*fPidfile, os.O_CREATE|os.O_WRONLY, 0644)
		if err != nil {
			log.Printf("E! Unable to create pidfile: %s", err)
		} else {
			fmt.Fprintf(f, "%d\n", os.Getpid())

			f.Close()

			defer func() {
				err := os.Remove(*fPidfile)
				if err != nil {
					log.Printf("E! Unable to remove pidfile: %s", err)
				}
			}()
		}
	}

	return ag.Run(ctx)
}