main.go

/*
Copyright 2022.

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"
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"runtime"
	"strings"

	bookkeeperv1alpha1 "github.com/pravega/bookkeeper-operator/api/v1alpha1"
	"github.com/pravega/bookkeeper-operator/controllers"
	controllerconfig "github.com/pravega/bookkeeper-operator/pkg/controller/config"
	"github.com/pravega/bookkeeper-operator/pkg/util"
	"github.com/pravega/bookkeeper-operator/pkg/version"
	"github.com/sirupsen/logrus"
	apimachineryruntime "k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	_ "k8s.io/client-go/plugin/pkg/client/auth"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
	_ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client/config"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	//+kubebuilder:scaffold:imports
)

var (
	versionFlag bool
	webhookFlag bool
	log         = ctrl.Log.WithName("cmd")
	scheme      = apimachineryruntime.NewScheme()
)

func init() {
	flag.BoolVar(&versionFlag, "version", false, "Show version and quit")
	flag.BoolVar(&controllerconfig.TestMode, "test", false, "Enable test mode. Do not use this flag in production")
	flag.BoolVar(&controllerconfig.DisableFinalizer, "disableFinalizer", false, "Disable finalizers for bookkeeperclusters. Use this flag with awareness of the consequences")
	flag.BoolVar(&webhookFlag, "webhook", true, "Enable webhook, the default is enabled.")
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(bookkeeperv1alpha1.AddToScheme(scheme))
}

func printVersion() {
	log.Info(fmt.Sprintf("bookkeeper-operator Version: %v", version.Version))
	log.Info(fmt.Sprintf("Git SHA: %s", version.GitSHA))
	log.Info(fmt.Sprintf("Go Version: %s", runtime.Version()))
	log.Info(fmt.Sprintf("Go OS/Arch: %s/%s", runtime.GOOS, runtime.GOARCH))
}

func main() {
	var metricsAddr string
	flag.StringVar(&metricsAddr, "metrics-bind-address", "127.0.0.1:6000", "The address the metric endpoint binds to.")

	flag.Parse()

	ctrl.SetLogger(zap.New(zap.UseDevMode(false)))

	printVersion()

	if versionFlag {
		os.Exit(0)
	}

	if controllerconfig.TestMode {
		logrus.Warn("----- Running in test mode. Make sure you are NOT in production -----")
	}

	if controllerconfig.DisableFinalizer {
		logrus.Warn("----- Running with finalizer disabled. -----")
	}

	// Get a config to talk to the apiserver
	cfg, err := config.GetConfig()
	if err != nil {
		logrus.Fatal(err)
	}

	operatorNs, err := GetOperatorNamespace()
	if err != nil {
		log.Error(err, "failed to get operator namespace")
		os.Exit(1)
	}

	namespaces, err := getWatchNamespace()
	if err != nil {
		log.Error(err, "unable to get WatchNamespace, "+
			"the manager will watch and manage resources in all namespaces")
	}

	// Become the leader before proceeding
	err = util.BecomeLeader(context.TODO(), cfg, "bookkeeper-operator-lock", operatorNs)
	if err != nil {
		log.Error(err, "")
		os.Exit(1)
	}

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme:             scheme,
		Namespace:          namespaces,
		MetricsBindAddress: metricsAddr,
		Port:               9443,
	})
	if err != nil {
		log.Error(err, "unable to start manager")
		os.Exit(1)
	}

	log.Info("Registering Components")

	if err = (&controllers.BookkeeperClusterReconciler{
		Client: mgr.GetClient(),
		Scheme: mgr.GetScheme(),
	}).SetupWithManager(mgr); err != nil {
		log.Error(err, "unable to create controller", "controller", "BookkeeperCluster")
		os.Exit(1)
	}

	bookkeeperv1alpha1.Mgr = mgr
	if webhookFlag {
		if err = (&bookkeeperv1alpha1.BookkeeperCluster{}).SetupWebhookWithManager(mgr); err != nil {
			log.Error(err, "unable to create webhook", "webhook", "BookkeeperCluster")
			os.Exit(1)
		}
	}
	//+kubebuilder:scaffold:builder

	log.Info("Webhook Setup completed")
	log.Info("Starting the Cmd")

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

func GetOperatorNamespace() (string, error) {
	nsBytes, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
	if err != nil {
		if os.IsNotExist(err) {
			return "", errors.New("file does not exist")
		}
		return "", err
	}
	ns := strings.TrimSpace(string(nsBytes))
	return ns, nil
}

// getWatchNamespace returns the Namespace the operator should be watching for changes
func getWatchNamespace() (string, error) {
	// WatchNamespaceEnvVar is the constant for env variable WATCH_NAMESPACE
	// which specifies the Namespace to watch.
	// An empty value means the operator is running with cluster scope.
	var watchNamespaceEnvVar = "WATCH_NAMESPACE"

	ns, found := os.LookupEnv(watchNamespaceEnvVar)
	if !found {
		return "", fmt.Errorf("%s must be set", watchNamespaceEnvVar)
	}
	return ns, nil
}