main.go

/*
Copyright 2022 Nutanix

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.
*/

package main

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

	"github.com/go-logr/logr"
	"github.com/spf13/pflag"
	"go.uber.org/zap/zapcore"
	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	"k8s.io/client-go/informers"
	coreinformers "k8s.io/client-go/informers/core/v1"
	"k8s.io/client-go/kubernetes"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	_ "k8s.io/client-go/plugin/pkg/client/auth"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/cache"
	capiv1 "sigs.k8s.io/cluster-api/api/v1beta1"
	bootstrapv1 "sigs.k8s.io/cluster-api/bootstrap/kubeadm/api/v1beta1"
	capiflags "sigs.k8s.io/cluster-api/util/flags"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	"sigs.k8s.io/controller-runtime/pkg/manager"

	infrav1alpha4 "github.com/nutanix-cloud-native/cluster-api-provider-nutanix/api/v1alpha4" //nolint:staticcheck // deprecated package; will be removed in one of the next releases
	infrav1 "github.com/nutanix-cloud-native/cluster-api-provider-nutanix/api/v1beta1"
	"github.com/nutanix-cloud-native/cluster-api-provider-nutanix/controllers"
	//+kubebuilder:scaffold:imports
)

var scheme = runtime.NewScheme()

// gitCommitHash is the git commit hash of the code that is running.
var gitCommitHash string

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(capiv1.AddToScheme(scheme))
	utilruntime.Must(bootstrapv1.AddToScheme(scheme))
	utilruntime.Must(infrav1alpha4.AddToScheme(scheme))
	utilruntime.Must(infrav1.AddToScheme(scheme))
	//+kubebuilder:scaffold:scheme
}

const (
	// DefaultMaxConcurrentReconciles is the default maximum number of concurrent reconciles
	defaultMaxConcurrentReconciles = 10
)

type managerConfig struct {
	enableLeaderElection               bool
	probeAddr                          string
	concurrentReconcilesNutanixCluster int
	concurrentReconcilesNutanixMachine int
	diagnosticsOptions                 capiflags.DiagnosticsOptions

	logger     logr.Logger
	restConfig *rest.Config
}

func parseFlags(config *managerConfig) {
	capiflags.AddDiagnosticsOptions(pflag.CommandLine, &config.diagnosticsOptions)
	pflag.StringVar(&config.probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
	pflag.BoolVar(&config.enableLeaderElection, "leader-elect", false,
		"Enable leader election for controller manager. Enabling this will ensure there is only one active controller manager.")
	var maxConcurrentReconciles int
	pflag.IntVar(&maxConcurrentReconciles, "max-concurrent-reconciles", defaultMaxConcurrentReconciles,
		"The maximum number of allowed, concurrent reconciles.")

	opts := zap.Options{
		TimeEncoder: zapcore.RFC3339TimeEncoder,
	}
	opts.BindFlags(flag.CommandLine)

	logger := zap.New(zap.UseFlagOptions(&opts))
	ctrl.SetLogger(logger)
	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
	pflag.Parse()

	config.concurrentReconcilesNutanixCluster = maxConcurrentReconciles
	config.concurrentReconcilesNutanixMachine = maxConcurrentReconciles
}

func setupLogger() logr.Logger {
	return ctrl.Log.WithName("setup")
}

func addHealthChecks(mgr manager.Manager) error {
	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
		return fmt.Errorf("unable to set up health check: %w", err)
	}

	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
		return fmt.Errorf("unable to set up ready check: %w", err)
	}

	return nil
}

func createInformers(ctx context.Context, mgr manager.Manager) (coreinformers.SecretInformer, coreinformers.ConfigMapInformer, error) {
	// Create a secret informer for the Nutanix client
	clientset, err := kubernetes.NewForConfig(mgr.GetConfig())
	if err != nil {
		return nil, nil, fmt.Errorf("unable to create clientset for management cluster: %w", err)
	}

	informerFactory := informers.NewSharedInformerFactory(clientset, time.Minute)
	secretInformer := informerFactory.Core().V1().Secrets()
	informer := secretInformer.Informer()
	go informer.Run(ctx.Done())
	cache.WaitForCacheSync(ctx.Done(), informer.HasSynced)

	configMapInformer := informerFactory.Core().V1().ConfigMaps()
	cmInformer := configMapInformer.Informer()
	go cmInformer.Run(ctx.Done())
	cache.WaitForCacheSync(ctx.Done(), cmInformer.HasSynced)

	return secretInformer, configMapInformer, nil
}

func setupNutanixClusterController(ctx context.Context, mgr manager.Manager, secretInformer coreinformers.SecretInformer,
	configMapInformer coreinformers.ConfigMapInformer, opts ...controllers.ControllerConfigOpts,
) error {
	clusterCtrl, err := controllers.NewNutanixClusterReconciler(
		mgr.GetClient(),
		secretInformer,
		configMapInformer,
		mgr.GetScheme(),
		opts...,
	)
	if err != nil {
		return fmt.Errorf("unable to create NutanixCluster controller: %w", err)
	}

	if err := clusterCtrl.SetupWithManager(ctx, mgr); err != nil {
		return fmt.Errorf("unable to setup NutanixCluster controller with manager: %w", err)
	}

	return nil
}

func setupNutanixMachineController(ctx context.Context, mgr manager.Manager, secretInformer coreinformers.SecretInformer,
	configMapInformer coreinformers.ConfigMapInformer, opts ...controllers.ControllerConfigOpts,
) error {
	machineCtrl, err := controllers.NewNutanixMachineReconciler(
		mgr.GetClient(),
		secretInformer,
		configMapInformer,
		mgr.GetScheme(),
		opts...,
	)
	if err != nil {
		return fmt.Errorf("unable to create NutanixMachine controller: %w", err)
	}

	if err := machineCtrl.SetupWithManager(ctx, mgr); err != nil {
		return fmt.Errorf("unable to setup NutanixMachine controller with manager: %w", err)
	}

	return nil
}

func runManager(ctx context.Context, mgr manager.Manager, config *managerConfig) error {
	secretInformer, configMapInformer, err := createInformers(ctx, mgr)
	if err != nil {
		return fmt.Errorf("unable to create informers: %w", err)
	}

	clusterControllerOpts := []controllers.ControllerConfigOpts{
		controllers.WithMaxConcurrentReconciles(config.concurrentReconcilesNutanixCluster),
	}

	if err := setupNutanixClusterController(ctx, mgr, secretInformer, configMapInformer, clusterControllerOpts...); err != nil {
		return fmt.Errorf("unable to setup controllers: %w", err)
	}

	machineControllerOpts := []controllers.ControllerConfigOpts{
		controllers.WithMaxConcurrentReconciles(config.concurrentReconcilesNutanixMachine),
	}

	if err := setupNutanixMachineController(ctx, mgr, secretInformer, configMapInformer, machineControllerOpts...); err != nil {
		return fmt.Errorf("unable to setup controllers: %w", err)
	}

	config.logger.Info("starting CAPX Controller Manager")
	if err := mgr.Start(ctx); err != nil {
		return fmt.Errorf("problem running manager: %w", err)
	}

	return nil
}

func initializeManager(config *managerConfig) (manager.Manager, error) {
	mgr, err := ctrl.NewManager(config.restConfig, ctrl.Options{
		Scheme:                 scheme,
		Metrics:                capiflags.GetDiagnosticsOptions(config.diagnosticsOptions),
		HealthProbeBindAddress: config.probeAddr,
		LeaderElection:         config.enableLeaderElection,
		LeaderElectionID:       "f265110d.cluster.x-k8s.io",
	})
	if err != nil {
		return nil, fmt.Errorf("unable to create manager: %w", err)
	}

	if err := addHealthChecks(mgr); err != nil {
		return nil, fmt.Errorf("unable to add health checks to manager: %w", err)
	}

	return mgr, nil
}

func main() {
	logger := setupLogger()

	restConfig := ctrl.GetConfigOrDie()

	config := &managerConfig{
		logger:     logger,
		restConfig: restConfig,
	}
	parseFlags(config)

	logger.Info("Initializing Nutanix Cluster API Infrastructure Provider", "Git Hash", gitCommitHash)
	mgr, err := initializeManager(config)
	if err != nil {
		logger.Error(err, "unable to create manager")
		os.Exit(1)
	}

	// Set up the context that's going to be used in controllers and for the manager.
	ctx := ctrl.SetupSignalHandler()
	if err := runManager(ctx, mgr, config); err != nil {
		logger.Error(err, "problem running manager")
		os.Exit(1)
	}
}