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			258 lines
		
	
	
		
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			258 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| /*
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| Copyright 2016 The Kubernetes Authors.
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| 
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| Licensed under the Apache License, Version 2.0 (the "License");
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| you may not use this file except in compliance with the License.
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| You may obtain a copy of the License at
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| 
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|     http://www.apache.org/licenses/LICENSE-2.0
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| 
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| Unless required by applicable law or agreed to in writing, software
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| distributed under the License is distributed on an "AS IS" BASIS,
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| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| See the License for the specific language governing permissions and
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| limitations under the License.
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| */
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| 
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| package certificates
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| 
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| import (
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| 	"fmt"
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| 	"reflect"
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| 	"strings"
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| 	"time"
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| 
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| 	"k8s.io/kubernetes/pkg/api"
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| 	"k8s.io/kubernetes/pkg/apis/certificates"
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| 	"k8s.io/kubernetes/pkg/client/cache"
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| 	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
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| 	unversionedcore "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset/typed/core/unversioned"
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| 	"k8s.io/kubernetes/pkg/client/record"
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| 	"k8s.io/kubernetes/pkg/controller"
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| 	"k8s.io/kubernetes/pkg/controller/framework"
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| 	"k8s.io/kubernetes/pkg/runtime"
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| 	utilcertificates "k8s.io/kubernetes/pkg/util/certificates"
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| 	utilruntime "k8s.io/kubernetes/pkg/util/runtime"
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| 	"k8s.io/kubernetes/pkg/util/wait"
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| 	"k8s.io/kubernetes/pkg/util/workqueue"
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| 	"k8s.io/kubernetes/pkg/watch"
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| 
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| 	"github.com/cloudflare/cfssl/config"
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| 	"github.com/cloudflare/cfssl/signer"
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| 	"github.com/cloudflare/cfssl/signer/local"
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| 	"github.com/golang/glog"
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| )
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| 
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| type CertificateController struct {
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| 	kubeClient clientset.Interface
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| 
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| 	// CSR framework and store
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| 	csrController *framework.Controller
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| 	csrStore      cache.StoreToCertificateRequestLister
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| 
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| 	// To allow injection of updateCertificateRequestStatus for testing.
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| 	updateHandler func(csr *certificates.CertificateSigningRequest) error
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| 	syncHandler   func(csrKey string) error
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| 
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| 	approveAllKubeletCSRsForGroup string
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| 
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| 	signer *local.Signer
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| 
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| 	queue *workqueue.Type
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| }
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| 
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| func NewCertificateController(kubeClient clientset.Interface, syncPeriod time.Duration, caCertFile, caKeyFile string, approveAllKubeletCSRsForGroup string) (*CertificateController, error) {
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| 	// Send events to the apiserver
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| 	eventBroadcaster := record.NewBroadcaster()
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| 	eventBroadcaster.StartLogging(glog.Infof)
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| 	eventBroadcaster.StartRecordingToSink(&unversionedcore.EventSinkImpl{Interface: kubeClient.Core().Events("")})
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| 
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| 	// Configure cfssl signer
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| 	// TODO: support non-default policy and remote/pkcs11 signing
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| 	policy := &config.Signing{
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| 		Default: config.DefaultConfig(),
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| 	}
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| 	ca, err := local.NewSignerFromFile(caCertFile, caKeyFile, policy)
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| 	if err != nil {
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| 		return nil, err
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| 	}
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| 
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| 	cc := &CertificateController{
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| 		kubeClient: kubeClient,
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| 		queue:      workqueue.NewNamed("certificate"),
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| 		signer:     ca,
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| 		approveAllKubeletCSRsForGroup: approveAllKubeletCSRsForGroup,
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| 	}
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| 
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| 	// Manage the addition/update of certificate requests
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| 	cc.csrStore.Store, cc.csrController = framework.NewInformer(
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| 		&cache.ListWatch{
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| 			ListFunc: func(options api.ListOptions) (runtime.Object, error) {
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| 				return cc.kubeClient.Certificates().CertificateSigningRequests().List(options)
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| 			},
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| 			WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
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| 				return cc.kubeClient.Certificates().CertificateSigningRequests().Watch(options)
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| 			},
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| 		},
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| 		&certificates.CertificateSigningRequest{},
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| 		syncPeriod,
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| 		framework.ResourceEventHandlerFuncs{
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| 			AddFunc: func(obj interface{}) {
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| 				csr := obj.(*certificates.CertificateSigningRequest)
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| 				glog.V(4).Infof("Adding certificate request %s", csr.Name)
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| 				cc.enqueueCertificateRequest(obj)
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| 			},
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| 			UpdateFunc: func(old, new interface{}) {
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| 				oldCSR := old.(*certificates.CertificateSigningRequest)
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| 				glog.V(4).Infof("Updating certificate request %s", oldCSR.Name)
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| 				cc.enqueueCertificateRequest(new)
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| 			},
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| 			DeleteFunc: func(obj interface{}) {
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| 				csr := obj.(*certificates.CertificateSigningRequest)
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| 				glog.V(4).Infof("Deleting certificate request %s", csr.Name)
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| 				cc.enqueueCertificateRequest(obj)
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| 			},
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| 		},
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| 	)
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| 	cc.syncHandler = cc.maybeSignCertificate
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| 	return cc, nil
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| }
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| 
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| // Run the main goroutine responsible for watching and syncing jobs.
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| func (cc *CertificateController) Run(workers int, stopCh <-chan struct{}) {
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| 	defer utilruntime.HandleCrash()
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| 	go cc.csrController.Run(stopCh)
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| 	glog.Infof("Starting certificate controller manager")
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| 	for i := 0; i < workers; i++ {
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| 		go wait.Until(cc.worker, time.Second, stopCh)
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| 	}
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| 	<-stopCh
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| 	glog.Infof("Shutting down certificate controller")
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| 	cc.queue.ShutDown()
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| }
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| 
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| // worker runs a thread that dequeues CSRs, handles them, and marks them done.
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| func (cc *CertificateController) worker() {
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| 	for {
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| 		func() {
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| 			key, quit := cc.queue.Get()
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| 			if quit {
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| 				return
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| 			}
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| 			defer cc.queue.Done(key)
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| 			err := cc.syncHandler(key.(string))
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| 			if err != nil {
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| 				glog.Errorf("Error syncing CSR: %v", err)
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| 			}
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| 		}()
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| 	}
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| }
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| 
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| func (cc *CertificateController) enqueueCertificateRequest(obj interface{}) {
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| 	key, err := controller.KeyFunc(obj)
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| 	if err != nil {
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| 		glog.Errorf("Couldn't get key for object %+v: %v", obj, err)
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| 		return
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| 	}
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| 	cc.queue.Add(key)
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| }
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| 
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| func (cc *CertificateController) updateCertificateRequestStatus(csr *certificates.CertificateSigningRequest) error {
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| 	_, updateErr := cc.kubeClient.Certificates().CertificateSigningRequests().UpdateStatus(csr)
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| 	if updateErr == nil {
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| 		// success!
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| 		return nil
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| 	}
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| 
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| 	// retry on failure
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| 	cc.enqueueCertificateRequest(csr)
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| 	return updateErr
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| }
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| 
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| // maybeSignCertificate will inspect the certificate request and, if it has
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| // been approved and meets policy expectations, generate an X509 cert using the
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| // cluster CA assets. If successful it will update the CSR approve subresource
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| // with the signed certificate.
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| func (cc *CertificateController) maybeSignCertificate(key string) error {
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| 	startTime := time.Now()
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| 	defer func() {
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| 		glog.V(4).Infof("Finished syncing certificate request %q (%v)", key, time.Now().Sub(startTime))
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| 	}()
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| 	obj, exists, err := cc.csrStore.Store.GetByKey(key)
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| 	if err != nil {
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| 		cc.queue.Add(key)
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| 		return err
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| 	}
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| 	if !exists {
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| 		glog.V(3).Infof("csr has been deleted: %v", key)
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| 		return nil
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| 	}
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| 	csr := obj.(*certificates.CertificateSigningRequest)
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| 
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| 	csr, err = cc.maybeAutoApproveCSR(csr)
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| 	if err != nil {
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| 		return fmt.Errorf("error auto approving csr: %v", err)
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| 	}
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| 
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| 	// At this point, the controller needs to:
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| 	// 1. Check the approval conditions
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| 	// 2. Generate a signed certificate
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| 	// 3. Update the Status subresource
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| 
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| 	if csr.Status.Certificate == nil && IsCertificateRequestApproved(csr) {
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| 		pemBytes := csr.Spec.Request
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| 		req := signer.SignRequest{Request: string(pemBytes)}
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| 		certBytes, err := cc.signer.Sign(req)
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| 		if err != nil {
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| 			return err
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| 		}
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| 		csr.Status.Certificate = certBytes
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| 	}
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| 
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| 	return cc.updateCertificateRequestStatus(csr)
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| }
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| 
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| func (cc *CertificateController) maybeAutoApproveCSR(csr *certificates.CertificateSigningRequest) (*certificates.CertificateSigningRequest, error) {
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| 	// short-circuit if we're not auto-approving
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| 	if cc.approveAllKubeletCSRsForGroup == "" {
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| 		return csr, nil
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| 	}
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| 	// short-circuit if we're already approved or denied
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| 	if approved, denied := getCertApprovalCondition(&csr.Status); approved || denied {
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| 		return csr, nil
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| 	}
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| 
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| 	isKubeletBootstrapGroup := false
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| 	for _, g := range csr.Spec.Groups {
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| 		if g == cc.approveAllKubeletCSRsForGroup {
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| 			isKubeletBootstrapGroup = true
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| 			break
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| 		}
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| 	}
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| 	if !isKubeletBootstrapGroup {
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| 		return csr, nil
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| 	}
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| 
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| 	x509cr, err := utilcertificates.ParseCertificateRequestObject(csr)
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| 	if err != nil {
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| 		glog.Errorf("unable to parse csr %q: %v", csr.ObjectMeta.Name, err)
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| 		return csr, nil
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| 	}
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| 	if !reflect.DeepEqual([]string{"system:nodes"}, x509cr.Subject.Organization) {
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| 		return csr, nil
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| 	}
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| 	if !strings.HasPrefix(x509cr.Subject.CommonName, "system:node:") {
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| 		return csr, nil
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| 	}
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| 	if len(x509cr.DNSNames)+len(x509cr.EmailAddresses)+len(x509cr.IPAddresses) != 0 {
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| 		return csr, nil
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| 	}
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| 
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| 	csr.Status.Conditions = append(csr.Status.Conditions, certificates.CertificateSigningRequestCondition{
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| 		Type:    certificates.CertificateApproved,
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| 		Reason:  "AutoApproved",
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| 		Message: "Auto approving of all kubelet CSRs is enabled on the controller manager",
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| 	})
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| 	return cc.kubeClient.Certificates().CertificateSigningRequests().UpdateApproval(csr)
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| }
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