main.go

package main

import (
	"flag"
	"os"

	// 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/plugin/pkg/client/auth"

	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	"k8s.io/client-go/discovery"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	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"
	"sigs.k8s.io/controller-runtime/pkg/webhook"

	bsv1 "redhat-developer/red-hat-developer-hub-operator/api/v1alpha2"
	controller "redhat-developer/red-hat-developer-hub-operator/controllers"

	openshift "github.com/openshift/api/route/v1"
	//+kubebuilder:scaffold:imports
)

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

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

	utilruntime.Must(bsv1.AddToScheme(scheme))

	utilruntime.Must(openshift.Install(scheme))
	//+kubebuilder:scaffold:scheme
}

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	var ownRuntime bool
	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.")
	flag.BoolVar(&ownRuntime, "own-runtime", true, "Making Backstage Controller own runtime objects. "+
		"If 'true' - all runtime objects created by Controller will be syncing with desired state configured by Controller")

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

	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme: scheme,
		Metrics: metricsserver.Options{
			BindAddress: metricsAddr,
		},
		WebhookServer: webhook.NewServer(webhook.Options{
			Port: 9443,
		}),
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         enableLeaderElection,
		LeaderElectionID:       "06bdbdd5.rhdh.redhat.com",
		// LeaderElectionReleaseOnCancel defines if the leader should step down voluntarily
		// when the Manager ends. This requires the binary to immediately end when the
		// Manager is stopped, otherwise, this setting is unsafe. Setting this significantly
		// speeds up voluntary leader transitions as the new leader don't have to wait
		// LeaseDuration time first.
		//
		// In the default scaffold provided, the program ends immediately after
		// the manager stops, so would be fine to enable this option. However,
		// if you are doing or is intended to do any operation such as perform cleanups
		// after the manager stops then its usage might be unsafe.
		// LeaderElectionReleaseOnCancel: true,
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	isOpenShift, err := isOpenshift()
	if err != nil {
		setupLog.Error(err, "unable to detect if a cluster is OpenShift. Make sure your cluster is running and accessible")
		os.Exit(1)
	}

	if err = (&controller.BackstageReconciler{
		Client:      mgr.GetClient(),
		Scheme:      mgr.GetScheme(),
		OwnsRuntime: ownRuntime,
		IsOpenShift: isOpenShift,
	}).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "Backstage")
		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 with parameters: ",
		"own-runtime", ownRuntime,
		"env.LOCALBIN", os.Getenv("LOCALBIN"),
		"isOpenShift", isOpenShift,
	)
	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
		setupLog.Error(err, "problem running manager")
		os.Exit(1)
	}
}

// Automatically detects if the cluster the operator running on is OpenShift
func isOpenshift() (bool, error) {
	restConfig := ctrl.GetConfigOrDie()
	dcl, err := discovery.NewDiscoveryClientForConfig(restConfig)
	if err != nil {
		return false, err
	}

	apiList, err := dcl.ServerGroups()
	if err != nil {
		return false, err
	}

	apiGroups := apiList.Groups
	for i := 0; i < len(apiGroups); i++ {
		if apiGroups[i].Name == "route.openshift.io" {
			return true, nil
		}
	}

	return false, nil
}