main.go

/*
Copyright 2023 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// main is the main package for the Cluster API Core Provider.
package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"time"

	"github.com/spf13/pflag"
	corev1 "k8s.io/api/core/v1"
	rbacv1 "k8s.io/api/rbac/v1"
	"k8s.io/apimachinery/pkg/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	"k8s.io/client-go/tools/leaderelection/resourcelock"
	cliflag "k8s.io/component-base/cli/flag"
	"k8s.io/component-base/logs"
	logsv1 "k8s.io/component-base/logs/api/v1"
	_ "k8s.io/component-base/logs/json/register"
	"k8s.io/klog/v2"
	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
	"sigs.k8s.io/cluster-api/controllers/remote"
	"sigs.k8s.io/cluster-api/feature"
	"sigs.k8s.io/cluster-api/util/flags"
	"sigs.k8s.io/cluster-api/version"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/cache"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/webhook"

	infrav1 "github.com/fabriziopandini/cluster-api-provider-goofy/api/v1alpha1"
	// +kubebuilder:scaffold:imports
	"github.com/fabriziopandini/cluster-api-provider-goofy/controllers"
	"github.com/fabriziopandini/cluster-api-provider-goofy/internal/cloud"
	cloudv1 "github.com/fabriziopandini/cluster-api-provider-goofy/internal/cloud/api/v1alpha1"
	"github.com/fabriziopandini/cluster-api-provider-goofy/internal/server"
)

var (
	scheme      = runtime.NewScheme()
	cloudScheme = runtime.NewScheme()
	setupLog    = ctrl.Log.WithName("setup")

	// flags.
	metricsBindAddr             string
	enableLeaderElection        bool
	leaderElectionLeaseDuration time.Duration
	leaderElectionRenewDeadline time.Duration
	leaderElectionRetryPeriod   time.Duration
	watchNamespace              string
	watchFilterValue            string
	profilerAddress             string
	clusterConcurrency          int
	machineConcurrency          int
	syncPeriod                  time.Duration
	restConfigQPS               float32
	restConfigBurst             int
	webhookPort                 int
	webhookCertDir              string
	healthAddr                  string
	tlsOptions                  = flags.TLSOptions{}
	logOptions                  = logs.NewOptions()
)

func init() {
	// scheme used for operating on the management cluster.
	_ = clientgoscheme.AddToScheme(scheme)
	_ = clusterv1.AddToScheme(scheme)
	_ = infrav1.AddToScheme(scheme)

	// scheme used for operating on the cloud resource.
	_ = cloudv1.AddToScheme(cloudScheme)
	_ = corev1.AddToScheme(cloudScheme)
	_ = rbacv1.AddToScheme(cloudScheme)
}

// InitFlags initializes the flags.
func InitFlags(fs *pflag.FlagSet) {
	logsv1.AddFlags(logOptions, fs)

	fs.StringVar(&metricsBindAddr, "metrics-bind-addr", "localhost:8080",
		"The address the metric endpoint binds to.")

	fs.BoolVar(&enableLeaderElection, "leader-elect", false,
		"Enable leader election for controller manager. Enabling this will ensure there is only one active controller manager.")

	fs.DurationVar(&leaderElectionLeaseDuration, "leader-elect-lease-duration", 15*time.Second,
		"Interval at which non-leader candidates will wait to force acquire leadership (duration string)")

	fs.DurationVar(&leaderElectionRenewDeadline, "leader-elect-renew-deadline", 10*time.Second,
		"Duration that the leading controller manager will retry refreshing leadership before giving up (duration string)")

	fs.DurationVar(&leaderElectionRetryPeriod, "leader-elect-retry-period", 2*time.Second,
		"Duration the LeaderElector clients should wait between tries of actions (duration string)")

	fs.StringVar(&watchNamespace, "namespace", "",
		"Namespace that the controller watches to reconcile cluster-api objects. If unspecified, the controller watches for cluster-api objects across all namespaces.")

	fs.StringVar(&watchFilterValue, "watch-filter", "",
		fmt.Sprintf("Label value that the controller watches to reconcile cluster-api objects. Label key is always %s. If unspecified, the controller watches for all cluster-api objects.", clusterv1.WatchLabel))

	fs.StringVar(&profilerAddress, "profiler-address", "",
		"Bind address to expose the pprof profiler (e.g. localhost:6060)")

	fs.IntVar(&clusterConcurrency, "cluster-concurrency", 10,
		"Number of clusters to process simultaneously")

	fs.IntVar(&machineConcurrency, "machine-concurrency", 10,
		"Number of machines to process simultaneously")

	fs.DurationVar(&syncPeriod, "sync-period", 10*time.Minute,
		"The minimum interval at which watched resources are reconciled (e.g. 15m)")

	fs.Float32Var(&restConfigQPS, "kube-api-qps", 20,
		"Maximum queries per second from the controller client to the Kubernetes API server. Defaults to 20")

	fs.IntVar(&restConfigBurst, "kube-api-burst", 30,
		"Maximum number of queries that should be allowed in one burst from the controller client to the Kubernetes API server. Default 30")

	fs.IntVar(&webhookPort, "webhook-port", 9443,
		"Webhook Server port")

	fs.StringVar(&webhookCertDir, "webhook-cert-dir", "/tmp/k8s-webhook-server/serving-certs/",
		"Webhook cert dir, only used when webhook-port is specified.")

	fs.StringVar(&healthAddr, "health-addr", ":9440",
		"The address the health endpoint binds to.")

	flags.AddTLSOptions(fs, &tlsOptions)

	feature.MutableGates.AddFlag(fs)
}

func main() {
	InitFlags(pflag.CommandLine)
	pflag.CommandLine.SetNormalizeFunc(cliflag.WordSepNormalizeFunc)
	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
	pflag.Parse()

	if err := logsv1.ValidateAndApply(logOptions, nil); err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	// klog.Background will automatically use the right logger.
	ctrl.SetLogger(klog.Background())

	restConfig := ctrl.GetConfigOrDie()
	restConfig.QPS = restConfigQPS
	restConfig.Burst = restConfigBurst
	restConfig.UserAgent = remote.DefaultClusterAPIUserAgent("cluster-api-goofy-controller-manager")

	tlsOptionOverrides, err := flags.GetTLSOptionOverrideFuncs(tlsOptions)
	if err != nil {
		setupLog.Error(err, "unable to add TLS settings to the webhook server")
		os.Exit(1)
	}

	var watchNamespaces []string
	if watchNamespace != "" {
		watchNamespaces = []string{watchNamespace}
	}

	ctrlOptions := ctrl.Options{
		Scheme:                     scheme,
		MetricsBindAddress:         metricsBindAddr,
		LeaderElection:             enableLeaderElection,
		LeaderElectionID:           "goofy-controller-leader-election-capi",
		LeaseDuration:              &leaderElectionLeaseDuration,
		RenewDeadline:              &leaderElectionRenewDeadline,
		RetryPeriod:                &leaderElectionRetryPeriod,
		LeaderElectionResourceLock: resourcelock.LeasesResourceLock,
		HealthProbeBindAddress:     healthAddr,
		PprofBindAddress:           profilerAddress,
		Cache: cache.Options{
			Namespaces: watchNamespaces,
			SyncPeriod: &syncPeriod,
		},
		Client: client.Options{
			Cache: &client.CacheOptions{
				DisableFor: []client.Object{
					&corev1.ConfigMap{},
					&corev1.Secret{},
				},
			},
		},
		WebhookServer: webhook.NewServer(
			webhook.Options{
				Port:    webhookPort,
				CertDir: webhookCertDir,
				TLSOpts: tlsOptionOverrides,
			},
		),
	}

	mgr, err := ctrl.NewManager(restConfig, ctrlOptions)
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	// Setup the context that's going to be used in controllers and for the manager.
	ctx := ctrl.SetupSignalHandler()

	setupChecks(mgr)
	setupIndexes(ctx, mgr)
	setupReconcilers(ctx, mgr)
	setupWebhooks(mgr)

	// +kubebuilder:scaffold:builder
	setupLog.Info("starting manager", "version", version.Get().String())
	if err := mgr.Start(ctx); err != nil {
		setupLog.Error(err, "problem running manager")
		os.Exit(1)
	}
}

func setupChecks(mgr ctrl.Manager) {
	if err := mgr.AddReadyzCheck("webhook", mgr.GetWebhookServer().StartedChecker()); err != nil {
		setupLog.Error(err, "unable to create ready check")
		os.Exit(1)
	}

	if err := mgr.AddHealthzCheck("webhook", mgr.GetWebhookServer().StartedChecker()); err != nil {
		setupLog.Error(err, "unable to create health check")
		os.Exit(1)
	}
}

func setupIndexes(_ context.Context, _ ctrl.Manager) {
}

func setupReconcilers(ctx context.Context, mgr ctrl.Manager) {
	// Start cloud manager
	cloudMgr := cloud.NewManager(cloudScheme)
	if err := cloudMgr.Start(ctx); err != nil {
		setupLog.Error(err, "unable to start a cloud manager")
		os.Exit(1)
	}

	// Start an http server
	podIP := os.Getenv("POD_IP")
	apiServerMux := server.NewWorkloadClustersMux(cloudMgr, podIP)

	// Setup reconcilers
	if err := (&controllers.GoofyClusterReconciler{
		Client:           mgr.GetClient(),
		CloudManager:     cloudMgr,
		APIServerMux:     apiServerMux,
		WatchFilterValue: watchFilterValue,
	}).SetupWithManager(ctx, mgr, concurrency(clusterConcurrency)); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "GoofyCluster")
		os.Exit(1)
	}

	if err := (&controllers.GoofyMachineReconciler{
		Client:           mgr.GetClient(),
		CloudManager:     cloudMgr,
		APIServerMux:     apiServerMux,
		WatchFilterValue: watchFilterValue,
	}).SetupWithManager(ctx, mgr, concurrency(machineConcurrency)); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "GoofyMachine")
		os.Exit(1)
	}
}

func setupWebhooks(mgr ctrl.Manager) {
	if err := (&infrav1.GoofyCluster{}).SetupWebhookWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create webhook", "webhook", "GoofyCluster")
		os.Exit(1)
	}

	if err := (&infrav1.GoofyMachine{}).SetupWebhookWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create webhook", "webhook", "GoofyMachine")
		os.Exit(1)
	}

	if err := (&infrav1.GoofyMachineTemplate{}).SetupWebhookWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create webhook", "webhook", "GoofyMachineTemplate")
		os.Exit(1)
	}
}

func concurrency(c int) controller.Options {
	return controller.Options{MaxConcurrentReconciles: c}
}