main.go

// Copyright © 2023 Ory Corp
// SPDX-License-Identifier: Apache-2.0

package main

import (
	"flag"
	"fmt"
	"os"
	"regexp"
	"strings"

	"github.com/ory/oathkeeper-maester/internal/validation"

	oathkeeperv1alpha1 "github.com/ory/oathkeeper-maester/api/v1alpha1"
	"github.com/ory/oathkeeper-maester/controllers"
	apiv1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/log/zap"
	// +kubebuilder:scaffold:imports
)

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

func init() {

	apiv1.AddToScheme(scheme)
	oathkeeperv1alpha1.AddToScheme(scheme)
	// +kubebuilder:scaffold:scheme
}

func main() {
	var metricsAddr string
	var enableLeaderElection bool
	var rulesConfigmapName string
	var rulesConfigmapNamespace string
	var rulesFileName string
	var rulesFilePath string

	var operator controllers.OperatorMode

	controllerCommand := flag.NewFlagSet("controller", flag.ExitOnError)
	sidecarCommand := flag.NewFlagSet("sidecar", flag.ExitOnError)

	flag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
	flag.BoolVar(&enableLeaderElection, "enable-leader-election", false,
		"Enable leader election for controller manager. Enabling this will ensure there is only one active controller manager.")

	controllerCommand.StringVar(&rulesConfigmapName, "rulesConfigmapName", "oathkeeper-rules", "Name of the Configmap that stores Oathkeeper rules.")
	controllerCommand.StringVar(&rulesConfigmapNamespace, "rulesConfigmapNamespace", "oathkeeper-maester-system", "Namespace of the Configmap that stores Oathkeeper rules.")
	controllerCommand.StringVar(&rulesFileName, "rulesFileName", "access-rules.json", "Name of the key in ConfigMap containing the rules.json")

	sidecarCommand.StringVar(&rulesFilePath, "rulesFilePath", "/etc/config/access-rules.json", "Path to the file with converted Oathkeeper rules")

	flag.Parse()

	ctrl.SetLogger(zap.New(zap.UseDevMode(true)))

	sideCarMode, err := selectMode(flag.Args(), controllerCommand, sidecarCommand)
	if err != nil {
		setupLog.Error(err, "problem parsing flags")
		os.Exit(1)
	}

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
		Scheme:             scheme,
		MetricsBindAddress: metricsAddr,
		LeaderElection:     enableLeaderElection,
		// Defaults to "" which means all namespaces
		Namespace: os.Getenv("NAMESPACE"),
	})
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		os.Exit(1)
	}

	if err := validateRulesFileName(rulesFileName); err != nil {
		setupLog.Error(err, "Validation error")
		os.Exit(1)
	}

	validationConfig := initValidationConfig()

	if sideCarMode {
		operator = &controllers.FilesOperator{
			Log:           ctrl.Log.WithName("controllers").WithName("Rule"),
			RulesFilePath: rulesFilePath,
		}
	} else {
		operator = &controllers.ConfigMapOperator{
			Client: mgr.GetClient(),
			Log:    ctrl.Log.WithName("controllers").WithName("Rule"),
			DefaultConfigMap: types.NamespacedName{
				Name:      rulesConfigmapName,
				Namespace: rulesConfigmapNamespace,
			},
			RulesFileName: rulesFileName,
		}
	}

	ruleReconciler := &controllers.RuleReconciler{
		Client:           mgr.GetClient(),
		Log:              ctrl.Log.WithName("controllers").WithName("Rule"),
		ValidationConfig: validationConfig,
		OperatorMode:     operator,
	}

	if err := ruleReconciler.SetupWithManager(mgr); err != nil {
		setupLog.Error(err, "unable to create controller", "controller", "Rule")
		os.Exit(1)
	}
	// +kubebuilder:scaffold:builder

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

func parseListOrDefault(list string, defaultArr []string, name string) []string {
	if list == "" {
		setupLog.Info(fmt.Sprintf("using default values for %s", name))
		return defaultArr
	}
	return parseList(list)
}

func parseList(list string) []string {
	return removeEmptyStrings(strings.Split(list, ","))
}

func removeEmptyStrings(list []string) []string {
	result := make([]string, 0)
	for _, s := range list {
		ts := strings.TrimSpace(s)
		if ts != "" {
			result = append(result, ts)
		}
	}

	return result
}

func initValidationConfig() validation.Config {
	authenticatorsAvailable := os.Getenv(oathkeeperv1alpha1.AuthenticatorsAvailableEnv)
	authorizersAvailable := os.Getenv(oathkeeperv1alpha1.AuthorizersAvailableEnv)
	mutatorsAvailable := os.Getenv(oathkeeperv1alpha1.MutatorsAvailableEnv)
	errorsAvailable := os.Getenv(oathkeeperv1alpha1.ErrorsAvailableEnv)
	return validation.Config{
		AuthenticatorsAvailable: parseListOrDefault(authenticatorsAvailable, oathkeeperv1alpha1.DefaultAuthenticatorsAvailable[:], oathkeeperv1alpha1.AuthenticatorsAvailableEnv),
		AuthorizersAvailable:    parseListOrDefault(authorizersAvailable, oathkeeperv1alpha1.DefaultAuthorizersAvailable[:], oathkeeperv1alpha1.AuthorizersAvailableEnv),
		MutatorsAvailable:       parseListOrDefault(mutatorsAvailable, oathkeeperv1alpha1.DefaultMutatorsAvailable[:], oathkeeperv1alpha1.MutatorsAvailableEnv),
		ErrorsAvailable:         parseListOrDefault(errorsAvailable, oathkeeperv1alpha1.DefaultErrorsAvailable[:], oathkeeperv1alpha1.ErrorsAvailableEnv),
	}
}

func validateRulesFileName(rfn string) error {
	match, _ := regexp.MatchString(oathkeeperv1alpha1.RulesFileNameRegexp, rfn)
	if match {
		return nil
	}
	return fmt.Errorf("rulesFileName: %s is not a valid name", rfn)
}

func selectMode(args []string, controllerCommand *flag.FlagSet, sidecarCommand *flag.FlagSet) (bool, error) {
	if len(args) < 1 {
		setupLog.Info("running in controller mode")
		return false, nil
	}

	switch args[0] {
	case "controller":
		if err := controllerCommand.Parse(args[1:]); err != nil {
			return false, err
		}
		setupLog.Info("running in controller mode")
		return false, nil
	case "sidecar":
		if err := sidecarCommand.Parse(args[1:]); err != nil {
			return false, err
		}
		setupLog.Info("running in sidecar mode")
		return true, nil
	default:
		return false, fmt.Errorf(`modes "controller" and "sidecar" are supported but got: %s`, args[0])
	}
}