issuer_controller.go

/*
Copyright 2023 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:https://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 controllers

import (
	"context"
	"errors"
	"fmt"
	"github.com/Keyfactor/ejbca-issuer/internal/issuer/signer"
	issuerutil "github.com/Keyfactor/ejbca-issuer/internal/issuer/util"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/types"
	utilerrors "k8s.io/apimachinery/pkg/util/errors"
	"time"

	ejbcaissuer "github.com/Keyfactor/ejbca-issuer/api/v1alpha1"
	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
)

const (
	issuerReadyConditionReason = "ejbca-issuer.IssuerController.Reconcile"
	defaultHealthCheckInterval = time.Minute
)

var (
	errGetAuthSecret        = errors.New("failed to get Secret containing credentials")
	errGetCaSecret          = errors.New("caSecretName specified a name, but failed to get Secret containing CA certificate")
	errHealthCheckerBuilder = errors.New("failed to build the healthchecker")
	errHealthCheckerCheck   = errors.New("healthcheck failed")
)

// IssuerReconciler reconciles a Issuer object
type IssuerReconciler struct {
	client.Client
	Kind                              string
	Scheme                            *runtime.Scheme
	ClusterResourceNamespace          string
	HealthCheckerBuilder              signer.HealthCheckerBuilder
	SecretAccessGrantedAtClusterLevel bool
}

//+kubebuilder:rbac:groups=ejbca-issuer.keyfactor.com,resources=issuers;clusterissuers,verbs=get;list;watch
//+kubebuilder:rbac:groups=ejbca-issuer.keyfactor.com,resources=issuers/status;clusterissuers/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ejbca-issuer.keyfactor.com,resources=issuers/finalizers,verbs=update

func (r *IssuerReconciler) newIssuer() (client.Object, error) {
	issuerGVK := ejbcaissuer.GroupVersion.WithKind(r.Kind)
	ro, err := r.Scheme.New(issuerGVK)
	if err != nil {
		return nil, err
	}
	return ro.(client.Object), nil
}

func (r *IssuerReconciler) Reconcile(ctx context.Context, req ctrl.Request) (result ctrl.Result, err error) {
	log := ctrl.LoggerFrom(ctx)

	issuer, err := r.newIssuer()
	if err != nil {
		log.Error(err, "Unrecognised issuer type")
		return ctrl.Result{}, nil
	}
	if err := r.Get(ctx, req.NamespacedName, issuer); err != nil {
		if err := client.IgnoreNotFound(err); err != nil {
			return ctrl.Result{}, fmt.Errorf("unexpected get error: %v", err)
		}
		log.Info("Not found. Ignoring.")
		return ctrl.Result{}, nil
	}

	issuerSpec, issuerStatus, err := issuerutil.GetSpecAndStatus(issuer)
	if err != nil {
		log.Error(err, "Unexpected error while getting issuer spec and status. Not retrying.")
		return ctrl.Result{}, nil
	}

	name, err := issuerutil.GetName(issuer)
	if err != nil {
		return ctrl.Result{}, err
	}

	// Always attempt to update the Ready condition
	defer func() {
		if err != nil {
			issuerutil.SetIssuerReadyCondition(ctx, name, r.Kind, issuerStatus, ejbcaissuer.ConditionFalse, issuerReadyConditionReason, err.Error())
		}
		if updateErr := r.Status().Update(ctx, issuer); updateErr != nil {
			err = utilerrors.NewAggregate([]error{err, updateErr})
			result = ctrl.Result{}
		}
	}()

	if ready := issuerutil.GetReadyCondition(issuerStatus); ready == nil {
		issuerutil.SetIssuerReadyCondition(ctx, name, r.Kind, issuerStatus, ejbcaissuer.ConditionUnknown, issuerReadyConditionReason, "First seen")
		return ctrl.Result{}, nil
	}

	secretName := types.NamespacedName{
		Name: issuerSpec.EjbcaSecretName,
	}

	switch issuer.(type) {
	case *ejbcaissuer.Issuer:
		secretName.Namespace = req.Namespace
	case *ejbcaissuer.ClusterIssuer:
		secretName.Namespace = r.ClusterResourceNamespace
	default:
		log.Error(fmt.Errorf("unexpected issuer type: %t", issuer), "Not retrying.")
		return ctrl.Result{}, nil
	}

	// If SecretAccessGrantedAtClusterLevel is false, we always look for the Secret in the same namespace as the Issuer
	if !r.SecretAccessGrantedAtClusterLevel {
		secretName.Namespace = r.ClusterResourceNamespace
	}

	var authSecret corev1.Secret
	if err := r.Get(ctx, secretName, &authSecret); err != nil {
		return ctrl.Result{}, fmt.Errorf("%w, secret name: %s, reason: %v", errGetAuthSecret, secretName, err)
	}

	// Retrieve the CA certificate secret
	caSecretName := types.NamespacedName{
		Name:      issuerSpec.CaBundleSecretName,
		Namespace: secretName.Namespace,
	}

	var caSecret corev1.Secret
	if issuerSpec.CaBundleSecretName != "" {
		// If the CA secret name is not specified, we will not attempt to retrieve it
		err = r.Get(ctx, caSecretName, &caSecret)
		if err != nil {
			return ctrl.Result{}, fmt.Errorf("%w, secret name: %s, reason: %v", errGetCaSecret, caSecretName, err)
		}
	}

	checker, err := r.HealthCheckerBuilder(ctx, issuerSpec, authSecret.Data, caSecret.Data)
	if err != nil {
		return ctrl.Result{}, fmt.Errorf("%w: %v", errHealthCheckerBuilder, err)
	}

	if err := checker.Check(); err != nil {
		return ctrl.Result{}, fmt.Errorf("%w: %v", errHealthCheckerCheck, err)
	}

	issuerutil.SetIssuerReadyCondition(ctx, name, r.Kind, issuerStatus, ejbcaissuer.ConditionTrue, issuerReadyConditionReason, "Success")
	return ctrl.Result{RequeueAfter: defaultHealthCheckInterval}, nil
}

func (r *IssuerReconciler) SetupWithManager(mgr ctrl.Manager) error {
	issuerType, err := r.newIssuer()
	if err != nil {
		return err
	}
	return ctrl.NewControllerManagedBy(mgr).
		For(issuerType).
		Complete(r)
}