func run()

in main.go [99:193]
75 lines of code
21 McCabe index (conditional complexity)

func run(ctx context.Context) {
	// Setup logging.
	opts := logger.LogOpts{LoggerName: "OSConfigAgent", UserAgent: agentconfig.UserAgent(), DisableLocalLogging: agentconfig.DisableLocalLogging()}
	if agentconfig.Stdout() {
		opts.Writers = []io.Writer{os.Stdout}
	}
	if runtime.GOOS == "windows" {
		opts.Writers = append(opts.Writers, &serialPort{"COM1"})
	}

	// If this call to WatchConfig fails (like a metadata error) we can't continue.
	if err := agentconfig.WatchConfig(ctx); err != nil {
		logger.Init(ctx, opts)
		logger.Fatalf("Error parsing metadata, agent cannot start: %v", err.Error())
	}
	opts.Debug = agentconfig.Debug()
	clog.DebugEnabled = agentconfig.Debug()
	opts.ProjectName = agentconfig.ProjectID()

	if err := logger.Init(ctx, opts); err != nil {
		fmt.Printf("Error initializing logger: %v", err)
		os.Exit(1)
	}
	ctx = clog.WithLabels(ctx, map[string]string{"instance_name": agentconfig.Name()})

	// Remove any existing restart file.
	if err := os.Remove(agentconfig.RestartFile()); err != nil && !os.IsNotExist(err) {
		clog.Errorf(ctx, "Error removing restart signal file: %v", err)
	}

	// On shutdown if the old restart file exists, and there is nothing else in that old directory,
	// cleanup that directory ignoring all errors.
	// This ensures we only cleanup this directory if we were using it with an old version of the agent.
	deferredFuncs = append(deferredFuncs, func() {
		if runtime.GOOS == "linux" && util.Exists(agentconfig.OldRestartFile()) {
			os.Remove(agentconfig.OldRestartFile())

			files, err := ioutil.ReadDir(filepath.Dir(agentconfig.OldRestartFile()))
			if err != nil || len(files) > 0 {
				return
			}
			os.RemoveAll(filepath.Dir(agentconfig.OldRestartFile()))
		}
	})

	deferredFuncs = append(deferredFuncs, logger.Close, func() { clog.Infof(ctx, "OSConfig Agent (version %s) shutting down.", agentconfig.Version()) })

	obtainLock()

	// obtainLock adds functions to clear the lock at close.
	logger.DeferredFatalFuncs = append(logger.DeferredFatalFuncs, deferredFuncs...)

	clog.Infof(ctx, "OSConfig Agent (version %s) started.", agentconfig.Version())

	// Call RegisterAgent at least once every day, on start calling
	// of RegisterAgent is handled in the service loop.
	go func() {
		c := time.Tick(24 * time.Hour)
		for range c {
			if agentconfig.TaskNotificationEnabled() || agentconfig.GuestPoliciesEnabled() {
				registerAgent(ctx)
			}
		}
	}()

	switch action := flag.Arg(0); action {
	case "", "run", "noservice":
		runServiceLoop(ctx)
	case "inventory", "osinventory":
		client, err := agentendpoint.NewClient(ctx)
		if err != nil {
			logger.Fatalf("%v", err.Error())
		}
		tasker.Enqueue(ctx, "Report OSInventory", func() {
			client.ReportInventory(ctx)
		})
		tasker.Close()
		return
	case "gp", "policies", "guestpolicies", "ospackage":
		policies.Run(ctx)
		tasker.Close()
		return
	case "w", "waitfortasknotification", "ospatch":
		client, err := agentendpoint.NewClient(ctx)
		if err != nil {
			logger.Fatalf("%v", err.Error())
		}
		client.WaitForTaskNotification(ctx)
		select {
		case <-ctx.Done():
		}
	default:
		logger.Fatalf("Unknown arg %q", action)
	}
}