main.go

package main

import (
	"flag"
	"os"
	"time"

	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	"k8s.io/klog/v2"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
)

var scheme = runtime.NewScheme()

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
}

func main() {
	var (
		metricsAddr       string
		probeAddr         string
		leaderElectionID  string
		notReadyThreshold time.Duration
		reconcileInterval time.Duration
	)

	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
	flag.StringVar(&leaderElectionID, "leader-election-id", "node-taint-controller.example.com", "The ID of the leader election.")
	flag.DurationVar(&notReadyThreshold, "not-ready-threshold", 5*time.Minute, "Duration a node must be NotReady before tainting.")
	flag.DurationVar(&reconcileInterval, "reconcile-interval", 30*time.Second, "How often to re-check node status.")

	opts := zap.Options{Development: false}
	opts.BindFlags(flag.CommandLine)
	flag.Parse()

	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
	klog.SetLogger(ctrl.Log)
	log := ctrl.Log.WithName("setup")

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme:                 scheme,
		Metrics:                metricsserver.Options{BindAddress: metricsAddr},
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         true,
		LeaderElectionID:       leaderElectionID,
	})
	if err != nil {
		log.Error(err, "unable to create manager")
		os.Exit(1)
	}

	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
		log.Error(err, "unable to set up health check")
		os.Exit(1)
	}
	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
		log.Error(err, "unable to set up ready check")
		os.Exit(1)
	}

	notifier := NewNotifierFromEnv()
	if notifier != nil {
		log.Info("notifications enabled via SHOUTRRR_URLS")
	}

	reconciler := &NodeTaintReconciler{
		Client:            mgr.GetClient(),
		NotReadyThreshold: notReadyThreshold,
		ReconcileInterval: reconcileInterval,
		NotReadySince:     make(map[string]time.Time),
		Notifier:          notifier,
	}

	if err := ctrl.NewControllerManagedBy(mgr).
		For(&corev1.Node{}).
		Complete(reconciler); err != nil {
		log.Error(err, "unable to create controller")
		os.Exit(1)
	}

	log.Info("starting manager", "notReadyThreshold", notReadyThreshold, "reconcileInterval", reconcileInterval)
	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
		log.Error(err, "problem running manager")
		os.Exit(1)
	}
}