main.go

/*
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you 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"
	"os"
	"strings"

	"github.com/datainfrahq/druid-operator/controllers/druid"
	// 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"
	"sigs.k8s.io/controller-runtime/pkg/cache"

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

	druidv1alpha1 "github.com/datainfrahq/druid-operator/apis/druid/v1alpha1"
	druidingestioncontrollers "github.com/datainfrahq/druid-operator/controllers/ingestion"
	//+kubebuilder:scaffold:imports
)

var (
	scheme         = runtime.NewScheme()
	setupLog       = ctrl.Log.WithName("setup")
	watchNamespace = os.Getenv("WATCH_NAMESPACE")
)

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

	utilruntime.Must(druidv1alpha1.AddToScheme(scheme))
	//+kubebuilder:scaffold:scheme
}

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	var disableIngestionController 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(&disableIngestionController, "disable-ingestion-controller", false,
		"Disable the DruidIngestion controller. Use this if the DruidIngestion CRD is not installed.")
	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,
		MetricsBindAddress:     metricsAddr,
		Port:                   9443,
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         enableLeaderElection,
		LeaderElectionID:       "e6946145.apache.org",
		Namespace:              os.Getenv("WATCH_NAMESPACE"),
		NewCache:               watchNamespaceCache(),
		// 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)
	}

	if err = (druid.NewDruidReconciler(mgr)).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "Druid")
		os.Exit(1)
	}

	if !disableIngestionController {
		if err = (druidingestioncontrollers.NewDruidIngestionReconciler(mgr)).SetupWithManager(mgr); err != nil {
			setupLog.Error(err, "unable to create controller", "controller", "DruidIngestion")
			os.Exit(1)
		}
	} else {
		setupLog.Info("DruidIngestion controller is disabled")
	}

	//+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)
	}
}

func watchNamespaceCache() cache.NewCacheFunc {
	var managerWatchCache cache.NewCacheFunc
	ns := strings.Split(watchNamespace, ",")

	if len(ns) > 1 {
		for i := range ns {
			ns[i] = strings.TrimSpace(ns[i])
		}
		managerWatchCache = cache.MultiNamespacedCacheBuilder(ns)
		return managerWatchCache
	}
	managerWatchCache = (cache.NewCacheFunc)(nil)
	return managerWatchCache
}