258 lines
8.0 KiB
Go
258 lines
8.0 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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package certificates
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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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"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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"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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type CertificateController struct {
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kubeClient clientset.Interface
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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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// 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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approveAllKubeletCSRsForGroup string
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signer *local.Signer
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queue *workqueue.Type
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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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// 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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cc := &CertificateController{
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kubeClient: kubeClient,
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queue: workqueue.New(),
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signer: ca,
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approveAllKubeletCSRsForGroup: approveAllKubeletCSRsForGroup,
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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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// 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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// 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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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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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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// retry on failure
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cc.enqueueCertificateRequest(csr)
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return updateErr
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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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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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// 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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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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return cc.updateCertificateRequestStatus(csr)
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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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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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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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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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