Merge pull request #24 from kinvolk/invidian/main-cleanups

main.go fixes and improvements

Author: detiber

Diff for: go.mod

@@ -7,6 +7,7 @@ require (
 	k8s.io/api v0.17.16
 	k8s.io/apimachinery v0.17.16
 	k8s.io/client-go v0.17.16
+	k8s.io/klog v1.0.0
 	k8s.io/utils v0.0.0-20201110183641-67b214c5f920 // indirect
 	sigs.k8s.io/cluster-api v0.3.12
 	sigs.k8s.io/controller-runtime v0.5.14

Diff for: main.go

@@ -21,17 +21,18 @@ import (
 	"os"
 	"time"
 
-	"github.com/tinkerbell/cluster-api-provider-tinkerbell/controllers"
 	"k8s.io/apimachinery/pkg/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	"k8s.io/client-go/tools/record"
+	"k8s.io/klog"
+	"k8s.io/klog/klogr"
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1alpha3"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
-	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 
 	infrastructurev1alpha3 "github.com/tinkerbell/cluster-api-provider-tinkerbell/api/v1alpha3"
-	clusterv1 "sigs.k8s.io/cluster-api/api/v1alpha3"
+	"github.com/tinkerbell/cluster-api-provider-tinkerbell/controllers"
 	// +kubebuilder:scaffold:imports
 )
 
@@ -49,115 +50,105 @@ func init() {
 	// +kubebuilder:scaffold:scheme
 }
 
-//nolint:funlen,gomnd
-func main() {
-	var (
-		enableLeaderElection    bool
-		leaderElectionNamespace string
-		healthAddr              string
-		metricsAddr             string
-		webhookPort             int
-		syncPeriod              time.Duration
-		watchNamespace          string
-	)
+// optionsFromFlags parse CLI flags and converts them to controller runtime options.
+func optionsFromFlags() ctrl.Options {
+	klog.InitFlags(nil)
+
+	// Machine and cluster operations can create enough events to trigger the event recorder spam filter
+	// Setting the burst size higher ensures all events will be recorded and submitted to the API
+	broadcaster := record.NewBroadcasterWithCorrelatorOptions(record.CorrelatorOptions{
+		BurstSize: 100, //nolint:gomnd
+	})
+
+	var syncPeriod time.Duration
+
+	options := ctrl.Options{
+		Scheme:           scheme,
+		LeaderElectionID: "controller-leader-election-capt",
+		EventBroadcaster: broadcaster,
+		SyncPeriod:       &syncPeriod,
+	}
 
-	flag.BoolVar(&enableLeaderElection, "enable-leader-election", false,
+	flag.BoolVar(&options.LeaderElection, "enable-leader-election", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
 
-	flag.StringVar(
-		&leaderElectionNamespace,
-		"leader-election-namespace",
-		"",
+	flag.StringVar(&options.LeaderElectionNamespace, "leader-election-namespace", "",
 		"Namespace that the controller performs leader election in. "+
 			"If unspecified, the controller will discover which namespace it is running in.",
 	)
 
-	flag.StringVar(&healthAddr,
-		"health-addr",
-		":9440",
-		"The address the health endpoint binds to.",
-	)
+	flag.StringVar(&options.HealthProbeBindAddress, "health-addr", ":9440", "The address the health endpoint binds to.")
 
-	flag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
+	flag.StringVar(&options.MetricsBindAddress, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
 
-	flag.DurationVar(&syncPeriod,
-		"sync-period",
-		10*time.Minute,
+	flag.DurationVar(&syncPeriod, "sync-period", 10*time.Minute, //nolint:gomnd
 		"The minimum interval at which watched resources are reconciled (e.g. 15m)",
 	)
 
-	flag.StringVar(
-		&watchNamespace,
-		"namespace",
-		"",
+	flag.StringVar(&options.Namespace, "namespace", "",
 		"Namespace that the controller watches to reconcile cluster-api objects. "+
 			"If unspecified, the controller watches for cluster-api objects across all namespaces.",
 	)
 
-	flag.IntVar(&webhookPort,
-		"webhook-port",
-		0,
+	flag.IntVar(&options.Port, "webhook-port", 0,
 		"Webhook Server port, disabled by default. When enabled, the manager will only "+
 			"work as webhook server, no reconcilers are installed.",
 	)
 
 	flag.Parse()
 
-	ctrl.SetLogger(zap.New(zap.UseDevMode(true)))
+	return options
+}
 
-	if watchNamespace != "" {
-		setupLog.Info("Watching cluster-api objects only in namespace for reconciliation", "namespace", watchNamespace)
+func validateOptions(options ctrl.Options) error {
+	if options.Namespace != "" {
+		setupLog.Info("Watching cluster-api objects only in namespace for reconciliation", "namespace", options.Namespace)
 	}
 
-	// Machine and cluster operations can create enough events to trigger the event recorder spam filter
-	// Setting the burst size higher ensures all events will be recorded and submitted to the API
-	broadcaster := record.NewBroadcasterWithCorrelatorOptions(record.CorrelatorOptions{
-		BurstSize: 100,
-	})
+	if options.Port != 0 {
+		// TODO: add the webhook configuration
+		return errors.New("webhook not implemented")
+	}
 
-	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
-		Scheme:                  scheme,
-		MetricsBindAddress:      metricsAddr,
-		Port:                    webhookPort,
-		EventBroadcaster:        broadcaster,
-		LeaderElection:          enableLeaderElection,
-		LeaderElectionID:        "controller-leader-election-capt",
-		LeaderElectionNamespace: leaderElectionNamespace,
-		Namespace:               watchNamespace,
-		SyncPeriod:              &syncPeriod,
-		HealthProbeBindAddress:  healthAddr,
-	})
+	return nil
+}
+
+func main() {
+	ctrl.SetLogger(klogr.New())
+
+	options := optionsFromFlags()
+
+	if err := validateOptions(options); err != nil {
+		setupLog.Error(err, "validating controllers configuration")
+		os.Exit(1)
+	}
+
+	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), options)
 	if err != nil {
 		setupLog.Error(err, "unable to start manager")
 		os.Exit(1)
 	}
 
 	// TODO: Get a Tinkerbell client.
 
-	if webhookPort == 0 {
-		if err = (&controllers.TinkerbellClusterReconciler{
-			Client:   mgr.GetClient(),
-			Log:      ctrl.Log.WithName("controllers").WithName("TinerellCluster"),
-			Recorder: mgr.GetEventRecorderFor("tinerellcluster-controller"),
-			Scheme:   mgr.GetScheme(),
-		}).SetupWithManager(mgr); err != nil {
-			setupLog.Error(err, "unable to create controller", "controller", "TinkerbellCluster")
-			os.Exit(1)
-		}
-
-		if err = (&controllers.TinkerbellMachineReconciler{
-			Client:   mgr.GetClient(),
-			Log:      ctrl.Log.WithName("controllers").WithName("TinkerbellMachine"),
-			Scheme:   mgr.GetScheme(),
-			Recorder: mgr.GetEventRecorderFor("tinkerbellmachine-controller"),
-		}).SetupWithManager(mgr); err != nil {
-			setupLog.Error(err, "unable to create controller", "controller", "TinkerbellMachine")
-			os.Exit(1)
-		}
-	} else {
-		// TODO: add the webhook configuration
-		setupLog.Error(errors.New("webhook not implemented"), "webhook", "not available")
+	if err = (&controllers.TinkerbellClusterReconciler{
+		Client:   mgr.GetClient(),
+		Log:      ctrl.Log.WithName("controllers").WithName("TinerellCluster"),
+		Recorder: mgr.GetEventRecorderFor("tinerellcluster-controller"),
+		Scheme:   mgr.GetScheme(),
+	}).SetupWithManager(mgr); err != nil {
+		setupLog.Error(err, "unable to create controller", "controller", "TinkerbellCluster")
+		os.Exit(1)
+	}
+
+	if err = (&controllers.TinkerbellMachineReconciler{
+		Client:   mgr.GetClient(),
+		Log:      ctrl.Log.WithName("controllers").WithName("TinkerbellMachine"),
+		Scheme:   mgr.GetScheme(),
+		Recorder: mgr.GetEventRecorderFor("tinkerbellmachine-controller"),
+	}).SetupWithManager(mgr); err != nil {
+		setupLog.Error(err, "unable to create controller", "controller", "TinkerbellMachine")
 		os.Exit(1)
 	}
 	// +kubebuilder:scaffold:builder