main.go

/*
Copyright © 2024 Keyfactor
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"
	"os"

	"github.com/Keyfactor/ejbca-k8s-csr-signer/internal/controllers"
	"github.com/Keyfactor/ejbca-k8s-csr-signer/internal/ejbca"
	"github.com/Keyfactor/ejbca-k8s-csr-signer/internal/util"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	"k8s.io/utils/clock"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
)

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

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

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var probeAddr string
	var clusterResourceNamespace string
	var printVersion bool
	var disableApprovedCheck bool
	var credsSecretName, configMapName, caCertConfigmapName string

	flag.StringVar(&credsSecretName, "credential-secret-name", "", "The name of the secret containing the EJBCA credentials")
	flag.StringVar(&configMapName, "configmap-name", "", "The name of the configmap containing the signer configuration")
	flag.StringVar(&caCertConfigmapName, "ca-cert-configmap-name", "", "The name of the configmap containing the root CAs of the EJBCA API server")

	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.StringVar(&clusterResourceNamespace, "cluster-resource-namespace", "", "The namespace for secrets in which cluster-scoped resources are found.")
	flag.BoolVar(&printVersion, "version", false, "Print version to stdout and exit")
	flag.BoolVar(&disableApprovedCheck, "disable-approved-check", false,
		"Disables waiting for CertificateRequests to have an approved condition before signing.")

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

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

	if clusterResourceNamespace == "" {
		var err error
		clusterResourceNamespace, err = util.GetInClusterNamespace()
		if err != nil {
			if errors.Is(err, errors.New("not running in-cluster")) {
				setupLog.Error(err, "please supply --cluster-resource-namespace")
			} else {
				setupLog.Error(err, "unexpected error while getting in-cluster Namespace")
			}
			os.Exit(1)
		}
	}

	if credsSecretName == "" {
		setupLog.Error(errors.New("please supply --credential-secret-name"), "")
		os.Exit(1)
	}

	if configMapName == "" {
		setupLog.Error(errors.New("please supply --configmap-name"), "")
		os.Exit(1)
	}

	ctx := context.Background()
	configClient, err := util.NewConfigClient(ctx)
	if err != nil {
		setupLog.Error(err, "error creating config client")
	}

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme:                 scheme,
		HealthProbeBindAddress: probeAddr,
		LeaderElection:         enableLeaderElection,
		LeaderElectionID:       "b68cef23.keyfactor.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.
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	credsSecret := types.NamespacedName{
		Namespace: clusterResourceNamespace,
		Name:      credsSecretName,
	}
	configMap := types.NamespacedName{
		Namespace: clusterResourceNamespace,
		Name:      configMapName,
	}
	caCertConfigmap := types.NamespacedName{
		Namespace: clusterResourceNamespace,
		Name:      caCertConfigmapName,
	}

	if err = (&controllers.CertificateSigningRequestReconciler{
		ConfigClient:             configClient,
		Client:                   mgr.GetClient(),
		Scheme:                   mgr.GetScheme(),
		SignerBuilder:            ejbca.NewSigner,
		ClusterResourceNamespace: clusterResourceNamespace,
		Clock:                    clock.RealClock{},
		CheckApprovedCondition:   !disableApprovedCheck,
		CheckServiceAccountScope: true,
		CredsSecret:              credsSecret,
		ConfigMap:                configMap,
		CaCertConfigmap:          caCertConfigmap,
	}).SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "CertificateSigningRequest")
		os.Exit(1)
	}

	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)
	}
}