func main()

in main.go [87:169]
65 lines of code
9 McCabe index (conditional complexity)

func main() {
	var configFile string
	flag.StringVar(&configFile, "config", "",
		"The controller will load its initial configuration from this file. "+
			"Omit this flag to use the default configuration values. ")

	var featureGates string
	flag.StringVar(&featureGates, "feature-gates", "", "A set of key=value pairs that describe feature gates for alpha/experimental features.")

	opts := zap.Options{
		TimeEncoder: zapcore.RFC3339NanoTimeEncoder,
		ZapOpts:     []zaplog.Option{zaplog.AddCaller()},
	}
	opts.BindFlags(flag.CommandLine)
	flag.Parse()

	if err := utilfeature.DefaultMutableFeatureGate.Set(featureGates); err != nil {
		setupLog.Error(err, "Unable to set flag gates for known features")
		os.Exit(1)
	}

	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
	setupLog.Info("Initializing", "gitVersion", version.GitVersion, "gitCommit", version.GitCommit)

	options, cfg, err := apply(configFile)
	if err != nil {
		setupLog.Error(err, "Unable to load the configuration")
		os.Exit(1)
	}

	metrics.Register()

	kubeConfig := ctrl.GetConfigOrDie()
	if kubeConfig.UserAgent == "" {
		kubeConfig.UserAgent = useragent.Default()
	}
	kubeConfig.QPS = *cfg.ClientConnection.QPS
	kubeConfig.Burst = int(*cfg.ClientConnection.Burst)
	setupLog.V(2).Info("K8S Client", "qps", kubeConfig.QPS, "burst", kubeConfig.Burst)
	mgr, err := ctrl.NewManager(kubeConfig, options)
	if err != nil {
		setupLog.Error(err, "Unable to start manager")
		os.Exit(1)
	}

	certsReady := make(chan struct{})

	if cfg.InternalCertManagement != nil && *cfg.InternalCertManagement.Enable {
		if err = cert.ManageCerts(mgr, cfg, certsReady); err != nil {
			setupLog.Error(err, "Unable to set up cert rotation")
			os.Exit(1)
		}
	} else {
		close(certsReady)
	}

	cCache := cache.New(mgr.GetClient(), cache.WithPodsReadyTracking(blockForPodsReady(&cfg)))
	queues := queue.NewManager(mgr.GetClient(), cCache)

	ctx := ctrl.SetupSignalHandler()
	setupIndexes(ctx, mgr, &cfg)

	setupProbeEndpoints(mgr)
	// Cert won't be ready until manager starts, so start a goroutine here which
	// will block until the cert is ready before setting up the controllers.
	// Controllers who register after manager starts will start directly.
	go setupControllers(mgr, cCache, queues, certsReady, &cfg)

	go func() {
		queues.CleanUpOnContext(ctx)
	}()
	go func() {
		cCache.CleanUpOnContext(ctx)
	}()

	setupScheduler(mgr, cCache, queues, &cfg)

	setupLog.Info("Starting manager")
	if err := mgr.Start(ctx); err != nil {
		setupLog.Error(err, "Could not run manager")
		os.Exit(1)
	}
}