main.go

/*
Copyright 2020.

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"
	"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/plugin/pkg/client/auth"

	routev1 "github.com/openshift/api/route/v1"
	apimachineryruntime "k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	apiregistrationv1 "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/cache"
	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
	"sigs.k8s.io/controller-runtime/pkg/webhook"

	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"

	kedav1alpha1 "github.com/kedacore/keda-olm-operator/apis/keda/v1alpha1"
	kedacontrollers "github.com/kedacore/keda-olm-operator/controllers/keda"
	"github.com/kedacore/keda-olm-operator/version"
	//+kubebuilder:scaffold:imports
)

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

const (
	serviceAccountNamespaceFile = "/var/run/secrets/kubernetes.io/serviceaccount/namespace"
)

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

	utilruntime.Must(routev1.AddToScheme(scheme))
	utilruntime.Must(kedav1alpha1.AddToScheme(scheme))
	utilruntime.Must(apiregistrationv1.AddToScheme(scheme))
	//+kubebuilder:scaffold:scheme
}

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	var certDir 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.StringVar(&certDir, "cert-dir", "/certs", "Directory where gRPC client certs secret is mounted.")
	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: true,
	}
	opts.BindFlags(flag.CommandLine)
	flag.Parse()

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

	installNamespace := getWatchNamespace()
	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:       "olm-operator.keda.sh",
		Cache:                  cache.Options{DefaultNamespaces: map[string]cache.Config{getWatchNamespace(): {}}},
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	if err = (&kedacontrollers.KedaControllerReconciler{
		Client:         mgr.GetClient(),
		Scheme:         mgr.GetScheme(),
		CertDir:        certDir,
		LeaderElection: enableLeaderElection,
	}).SetupWithManager(mgr, installNamespace, setupLog); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "KedaController")
		os.Exit(1)
	}
	if err = (&kedacontrollers.ConfigMapReconciler{
		Client: mgr.GetClient(),
		Log:    ctrl.Log.WithName("controllers").WithName("ConfigMap"),
		Scheme: mgr.GetScheme(),
	}).SetupWithManager(mgr, installNamespace); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "ConfigMap")
		os.Exit(1)
	}
	if err = (&kedacontrollers.SecretReconciler{
		Client: mgr.GetClient(),
		Log:    ctrl.Log.WithName("controllers").WithName("Secret"),
		Scheme: mgr.GetScheme(),
	}).SetupWithManager(mgr, installNamespace); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "Secret")
		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")
	setupLog.Info(fmt.Sprintf("KEDA Version: %s", version.Version))
	setupLog.Info(fmt.Sprintf("Git Commit: %s", version.GitCommit))
	setupLog.Info(fmt.Sprintf("Go Version: %s", runtime.Version()))
	setupLog.Info(fmt.Sprintf("Go OS/Arch: %s/%s", runtime.GOOS, runtime.GOARCH))

	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
// It tries to read this information from env variable `WATCH_NAMESPACE`. If not set
// or empty, it attempts to determine which namespace it is running in via the
// automounted service account data. If unavailable, namespace `keda` is used
func getWatchNamespace() string {
	var ns string
	var found bool
	if ns, found = os.LookupEnv("WATCH_NAMESPACE"); found && len(ns) > 0 {
		setupLog.Info(fmt.Sprintf("Using watch namespace '%s' from environment variable WATCH_NAMESPACE", ns))
	} else if nsBytes, err := os.ReadFile(serviceAccountNamespaceFile); err == nil {
		ns = strings.TrimSpace(string(nsBytes))
		setupLog.Info(fmt.Sprintf("Using watch namespace '%s' from service account namespace specified in %s", ns, serviceAccountNamespaceFile))
	} else {
		ns = "keda"
		setupLog.Info(fmt.Sprintf("Using default watch namespace '%s'", ns))
	}
	return ns
}