kubeadm: fix dry-run for kubelet-wait-bootstrap phase

Author: chrischdi

cmd/kubeadm/app/cmd/join.go

@@ -609,7 +609,9 @@ func (j *joinData) Client() (clientset.Interface, error) {
 			AppendReactor(dryRun.GetKubeadmConfigReactor()).
 			AppendReactor(dryRun.GetKubeadmCertsReactor()).
 			AppendReactor(dryRun.GetKubeProxyConfigReactor()).
-			AppendReactor(dryRun.GetKubeletConfigReactor())
+			AppendReactor(dryRun.GetKubeletConfigReactor()).
+			AppendReactor(dryRun.GetNodeReactor()).
+			AppendReactor(dryRun.PatchNodeReactor())
 
 		j.client = dryRun.FakeClient()
 		return j.client, nil

cmd/kubeadm/app/cmd/phases/join/kubelet.go

@@ -293,44 +293,55 @@ func runKubeletWaitBootstrapPhase(c workflow.RunData) (returnErr error) {
 		return err
 	}
 
-	bootstrapKubeConfigFile := filepath.Join(data.KubeConfigDir(), kubeadmconstants.KubeletBootstrapKubeConfigFileName)
-	// Deletes the bootstrapKubeConfigFile, so the credential used for TLS bootstrap is removed from disk
-	defer func() {
-		_ = os.Remove(bootstrapKubeConfigFile)
-	}()
-
-	// Apply patches to the in-memory kubelet configuration so that any configuration changes like kubelet healthz
-	// address and port options are respected during the wait below. WriteConfigToDisk already applied patches to
-	// the kubelet.yaml written to disk. This should be done after WriteConfigToDisk because both use the same config
-	// in memory and we don't want patches to be applied two times to the config that is written to disk.
-	if err := kubeletphase.ApplyPatchesToConfig(&initCfg.ClusterConfiguration, data.PatchesDir()); err != nil {
-		return errors.Wrap(err, "could not apply patches to the in-memory kubelet configuration")
-	}
+	var client clientset.Interface
 
-	// Now the kubelet will perform the TLS Bootstrap, transforming /etc/kubernetes/bootstrap-kubelet.conf to /etc/kubernetes/kubelet.conf
-	// Wait for the kubelet to create the /etc/kubernetes/kubelet.conf kubeconfig file. If this process
-	// times out, display a somewhat user-friendly message.
-	waiter := apiclient.NewKubeWaiter(nil, 0, os.Stdout)
-	waiter.SetTimeout(cfg.Timeouts.KubeletHealthCheck.Duration)
-	kubeletConfig := initCfg.ClusterConfiguration.ComponentConfigs[componentconfigs.KubeletGroup].Get()
-	kubeletConfigTyped, ok := kubeletConfig.(*kubeletconfig.KubeletConfiguration)
-	if !ok {
-		return errors.New("could not convert the KubeletConfiguration to a typed object")
-	}
-	if err := waiter.WaitForKubelet(kubeletConfigTyped.HealthzBindAddress, *kubeletConfigTyped.HealthzPort); err != nil {
-		fmt.Printf(kubeadmJoinFailMsg, err)
-		return err
-	}
+	if data.DryRun() {
+		fmt.Println("[kubelet-wait] Would wait for the kubelet to be bootstrapped")
 
-	if err := waitForTLSBootstrappedClient(cfg.Timeouts.TLSBootstrap.Duration); err != nil {
-		fmt.Printf(kubeadmJoinFailMsg, err)
-		return err
-	}
+		// Use the dry-run client.
+		if client, err = data.Client(); err != nil {
+			return errors.Wrap(err, "could not get client for dry-run")
+		}
+	} else {
+		bootstrapKubeConfigFile := filepath.Join(data.KubeConfigDir(), kubeadmconstants.KubeletBootstrapKubeConfigFileName)
+		// Deletes the bootstrapKubeConfigFile, so the credential used for TLS bootstrap is removed from disk
+		defer func() {
+			_ = os.Remove(bootstrapKubeConfigFile)
+		}()
 
-	// When we know the /etc/kubernetes/kubelet.conf file is available, get the client
-	client, err := kubeconfigutil.ClientSetFromFile(kubeadmconstants.GetKubeletKubeConfigPath())
-	if err != nil {
-		return err
+		// Apply patches to the in-memory kubelet configuration so that any configuration changes like kubelet healthz
+		// address and port options are respected during the wait below. WriteConfigToDisk already applied patches to
+		// the kubelet.yaml written to disk. This should be done after WriteConfigToDisk because both use the same config
+		// in memory and we don't want patches to be applied two times to the config that is written to disk.
+		if err := kubeletphase.ApplyPatchesToConfig(&initCfg.ClusterConfiguration, data.PatchesDir()); err != nil {
+			return errors.Wrap(err, "could not apply patches to the in-memory kubelet configuration")
+		}
+
+		// Now the kubelet will perform the TLS Bootstrap, transforming /etc/kubernetes/bootstrap-kubelet.conf to /etc/kubernetes/kubelet.conf
+		// Wait for the kubelet to create the /etc/kubernetes/kubelet.conf kubeconfig file. If this process
+		// times out, display a somewhat user-friendly message.
+		waiter := apiclient.NewKubeWaiter(nil, 0, os.Stdout)
+		waiter.SetTimeout(cfg.Timeouts.KubeletHealthCheck.Duration)
+		kubeletConfig := initCfg.ClusterConfiguration.ComponentConfigs[componentconfigs.KubeletGroup].Get()
+		kubeletConfigTyped, ok := kubeletConfig.(*kubeletconfig.KubeletConfiguration)
+		if !ok {
+			return errors.New("could not convert the KubeletConfiguration to a typed object")
+		}
+		if err := waiter.WaitForKubelet(kubeletConfigTyped.HealthzBindAddress, *kubeletConfigTyped.HealthzPort); err != nil {
+			fmt.Printf(kubeadmJoinFailMsg, err)
+			return err
+		}
+
+		if err := waitForTLSBootstrappedClient(cfg.Timeouts.TLSBootstrap.Duration); err != nil {
+			fmt.Printf(kubeadmJoinFailMsg, err)
+			return err
+		}
+
+		// When we know the /etc/kubernetes/kubelet.conf file is available, get the client
+		client, err = kubeconfigutil.ClientSetFromFile(kubeadmconstants.GetKubeletKubeConfigPath())
+		if err != nil {
+			return err
+		}
 	}
 
 	if !features.Enabled(initCfg.ClusterConfiguration.FeatureGates, features.NodeLocalCRISocket) {