main.go

/*
Copyright 2021.

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 (
	"flag"
	"fmt"
	"os"
	runt "runtime"
	"strings"

	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
	// to ensure that exec-entrypoint and run can make use of them.
	"k8s.io/client-go/kubernetes"
	_ "k8s.io/client-go/plugin/pkg/client/auth"

	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/cache"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"

	secv1 "github.com/openshift/api/security/v1"

	k8sv1alpha1 "github.com/nginxinc/nginx-ingress-operator/api/v1alpha1"
	"github.com/nginxinc/nginx-ingress-operator/controllers"
	"sigs.k8s.io/controller-runtime/pkg/client/config"
	//+kubebuilder:scaffold:imports
)

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

func printVersion() {
	setupLog.Info(fmt.Sprintf("Operator Version: %s", version))
	setupLog.Info(fmt.Sprintf("Go Version: %s", runt.Version()))
	setupLog.Info(fmt.Sprintf("Go OS/Arch: %s/%s", runt.GOOS, runt.GOARCH))
	setupLog.Info(fmt.Sprintf("Version of kubernetes: %v", controllers.RunningK8sVersion))
}

func init() {
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(k8sv1alpha1.AddToScheme(scheme))

	//+kubebuilder:scaffold:scheme
}

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	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.BoolVar(&enableLeaderElection, "leader-elect", false,
		"Enable leader election for controller manager. "+
			"Enabling this will ensure there is only one active controller manager.")
	opts := zap.Options{
		Development: false,
	}
	opts.BindFlags(flag.CommandLine)
	flag.Parse()

	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
	// Get a config to talk to the apiserver
	cfg, err := config.GetConfig()
	if err != nil {
		setupLog.Error(err, "problem getting k8s config")
		os.Exit(1)
	}
	clientset, err := kubernetes.NewForConfig(cfg)
	if err != nil {
		setupLog.Error(err, "problem creating clientset")
		os.Exit(1)
	}
	controllers.RunningK8sVersion, err = controllers.GetK8sVersion(clientset)
	if err != nil {
		setupLog.Error(err, "problem getting k8s version")
		os.Exit(1)
	}

	printVersion()

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

	options := ctrl.Options{
		Scheme:                 scheme,
		MetricsBindAddress:     metricsAddr,
		Port:                   9443,
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         enableLeaderElection,
		LeaderElectionID:       "ca5c10a7.nginx.org",
		Namespace:              watchNamespace,
	}

	// Add support for MultiNamespace set in WATCH_NAMESPACE (e.g ns1,ns2)
	if strings.Contains(watchNamespace, ",") {
		setupLog.Info("manager set up with multiple namespaces", "namespaces", watchNamespace)
		// configure cluster-scoped with MultiNamespacedCacheBuilder
		options.Namespace = ""
		options.NewCache = cache.MultiNamespacedCacheBuilder(strings.Split(watchNamespace, ","))
	}

	if options.Namespace != "" {
		setupLog.Info("manager set up with namespace", "namespace", options.Namespace)
	}

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

	// Setup Scheme for SCC if deployed in OpenShift
	sccAPIExists, err := controllers.VerifySCCAPIExists()
	if err != nil {
		setupLog.Error(err, "could not check if SCC API exists")
		os.Exit(1)
	}

	if sccAPIExists {
		utilruntime.Must(secv1.AddToScheme(scheme))
	}

	if err = (&controllers.NginxIngressControllerReconciler{
		Client:       mgr.GetClient(),
		Scheme:       mgr.GetScheme(),
		SccAPIExists: sccAPIExists,
		Mgr:          mgr,
	}).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "NginxIngressController")
		os.Exit(1)
	}
	//+kubebuilder:scaffold:builder
	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
		setupLog.Error(err, "unable to set up health check")
		os.Exit(1)
	}
	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
		setupLog.Error(err, "unable to set up ready check")
		os.Exit(1)
	}

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

// 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.
	watchNamespaceEnvVar := "WATCH_NAMESPACE"

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