You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: circuitbreakerrules_controller.go
    path of file: ./repos/sentinel-golang/pkg/datasource/k8s/controllers
    
    the code of the file until where you have to start completion: /*


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 controllers

import (
	"context"
	"net/http"

	"github.com/alibaba/sentinel-golang/core/circuitbreaker"
	"github.com/alibaba/sentinel-golang/logging"
	"github.com/go-logr/logr"
	"github.com/pkg/errors"
	k8sApiError "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"

	datasourcev1 "github.com/alibaba/sentinel-golang/pkg/datasource/k8s/api/v1alpha1"
)

// CircuitBreakerRulesReconciler reconciles a CircuitBreakerRules
    
func (r *CircuitBreakerRulesReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
	ctx := context.Background()
	log := r.Logger.WithValues("expectedNamespace", r.Namespace, "expectedCrName", r.ExpectedCrName, "req", req.String())

	if req.Namespace != r.Namespace {
		log.V(int(logging.DebugLevel)).Info("ignore unmatched namespace")
		return ctrl.Result{
			Requeue:      false,
			RequeueAfter: 0,
		}, nil
	}

	if req.Name != r.ExpectedCrName {
		return ctrl.Result{
			Requeue:      false,
			RequeueAfter: 0,
		}, nil
	}

	cbRulesCR := &datasourcev1.CircuitBreakerRules{}
	if err := r.Get(ctx, req.NamespacedName, cbRulesCR); err != nil {
		k8sApiErr, ok := err.(*k8sApiError.StatusError)
		if !ok {
			log.Error(err, "Fail to get datasourcev1.CircuitBreakerRules.")
			return ctrl.Result{
				Requeue:      false,
				RequeueAfter: 0,
			}, nil
		}
		if k8sApiErr.Status().Code != http.StatusNotFound {
			log.Error(err, "Fail to get datasourcev1.CircuitBreakerRules.")
			return ctrl.Result{
				Requeue:      false,
				RequeueAfter: 0,
			}, nil
		}
		log.Info("datasourcev1.CircuitBreakerRules had been deleted.")
		cbRulesCR = nil
	}

	var cbRules []*circuitbreaker.Rule
	if cbRulesCR != nil {
		log.Info("Get datasourcev1.CircuitBreakerRules", "rules:", cbRulesCR.Spec.Rules)
		cbRules = r.assembleCircuitBreakerRules(cbRulesCR)
	}
	_, err := circuitbreaker.LoadRules(cbRules)
	if err != nil {
		log.Error(err, "Fail to Load circuitbreaker.Rules")
		return ctrl.Result{
			Requeue:      false,
			RequeueAfter: 0,
		}, err
	}
	return ctrl.Result{}, nil
}