Merge pull request #70512 from neolit123/phase-wait-control-plane

kubeadm: graduate wait-control-plane phase

cmd/kubeadm/app/cmd/BUILD

@@ -53,7 +53,6 @@ go_library(
         "//cmd/kubeadm/app/util:go_default_library",
         "//cmd/kubeadm/app/util/apiclient:go_default_library",
         "//cmd/kubeadm/app/util/config:go_default_library",
-        "//cmd/kubeadm/app/util/dryrun:go_default_library",
         "//cmd/kubeadm/app/util/kubeconfig:go_default_library",
         "//cmd/kubeadm/app/util/runtime:go_default_library",
         "//cmd/kubeadm/app/util/staticpod:go_default_library",

cmd/kubeadm/app/cmd/init.go

@@ -24,7 +24,6 @@ import (
 	"path/filepath"
 	"strings"
 	"text/template"
-	"time"
 
 	"github.com/golang/glog"
 	"github.com/pkg/errors"
@@ -57,7 +56,6 @@ import (
 	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/apiclient"
 	configutil "k8s.io/kubernetes/cmd/kubeadm/app/util/config"
-	dryrunutil "k8s.io/kubernetes/cmd/kubeadm/app/util/dryrun"
 	kubeconfigutil "k8s.io/kubernetes/cmd/kubeadm/app/util/kubeconfig"
 	utilsexec "k8s.io/utils/exec"
 )
@@ -128,6 +126,8 @@ type initData struct {
 	dryRunDir             string
 	externalCA            bool
 	client                clientset.Interface
+	waiter                apiclient.Waiter
+	outputWriter          io.Writer
 }
 
 // NewCmdInit returns "kubeadm init" command.
@@ -168,12 +168,13 @@ func NewCmdInit(out io.Writer) *cobra.Command {
 	initRunner.AppendPhase(phases.NewKubeConfigPhase())
 	initRunner.AppendPhase(phases.NewControlPlanePhase())
 	initRunner.AppendPhase(phases.NewEtcdPhase())
+	initRunner.AppendPhase(phases.NewWaitControlPlanePhase())
 	// TODO: add other phases to the runner.
 
 	// sets the data builder function, that will be used by the runner
 	// both when running the entire workflow or single phases
 	initRunner.SetDataInitializer(func() (workflow.RunData, error) {
-		return newInitData(cmd, options)
+		return newInitData(cmd, options, out)
 	})
 
 	// binds the Runner to kubeadm init command by altering
@@ -270,7 +271,7 @@ func newInitOptions() *initOptions {
 // newInitData returns a new initData struct to be used for the execution of the kubeadm init workflow.
 // This func takes care of validating initOptions passed to the command, and then it converts
 // options into the internal InitConfiguration type that is used as input all the phases in the kubeadm init workflow
-func newInitData(cmd *cobra.Command, options *initOptions) (initData, error) {
+func newInitData(cmd *cobra.Command, options *initOptions, out io.Writer) (initData, error) {
 	// Re-apply defaults to the public kubeadm API (this will set only values not exposed/not set as a flags)
 	kubeadmscheme.Scheme.Default(options.externalcfg)
 
@@ -324,6 +325,7 @@ func newInitData(cmd *cobra.Command, options *initOptions) (initData, error) {
 		dryRunDir:             dryRunDir,
 		ignorePreflightErrors: ignorePreflightErrorsSet,
 		externalCA:            externalCA,
+		outputWriter:          out,
 	}, nil
 }
 
@@ -389,6 +391,11 @@ func (d initData) ExternalCA() bool {
 	return d.externalCA
 }
 
+// OutputWriter returns the io.Writer used to write output to by this command.
+func (d initData) OutputWriter() io.Writer {
+	return d.outputWriter
+}
+
 // Client returns a Kubernetes client to be used by kubeadm.
 // This function is implemented as a singleton, thus avoiding to recreate the client when it is used by different phases.
 // Important. This function must be called after the admin.conf kubeconfig file is created.
@@ -434,32 +441,16 @@ func runInit(i *initData, out io.Writer) error {
 
 	adminKubeConfigPath := filepath.Join(kubeConfigDir, kubeadmconstants.AdminKubeConfigFileName)
 
-	// If we're dry-running, print the generated manifests
-	if err := printFilesIfDryRunning(i.dryRun, manifestDir); err != nil {
-		return errors.Wrap(err, "error printing files on dryrun")
-	}
-
-	// Create a Kubernetes client and wait for the API server to be healthy (if not dryrunning)
-	glog.V(1).Infof("creating Kubernetes client")
-	client, err := createClient(i.cfg, i.dryRun)
+	// TODO: client and waiter are temporary until the rest of the phases that use them
+	// are removed from this function.
+	client, err := i.Client()
 	if err != nil {
-		return errors.Wrap(err, "error creating client")
+		return errors.Wrap(err, "failed to create client")
 	}
-
-	// waiter holds the apiclient.Waiter implementation of choice, responsible for querying the API server in various ways and waiting for conditions to be fulfilled
-	glog.V(1).Infof("[init] waiting for the API server to be healthy")
-	waiter := getWaiter(i, client)
-
-	fmt.Printf("[init] waiting for the kubelet to boot up the control plane as Static Pods from directory %q \n", kubeadmconstants.GetStaticPodDirectory())
-
-	if err := waitForKubeletAndFunc(waiter, waiter.WaitForAPI); err != nil {
-		ctx := map[string]string{
-			"Error": fmt.Sprintf("%v", err),
-		}
-
-		kubeletFailTempl.Execute(out, ctx)
-
-		return errors.New("couldn't initialize a Kubernetes cluster")
+	// TODO: NewControlPlaneWaiter should be converted to private after the self-hosting phase is removed.
+	waiter, err := phases.NewControlPlaneWaiter(i.dryRun, client, i.outputWriter)
+	if err != nil {
+		return errors.Wrap(err, "failed to create waiter")
 	}
 
 	// Upload currently used configuration to the cluster
@@ -594,18 +585,6 @@ func printJoinCommand(out io.Writer, adminKubeConfigPath, token string, skipToke
 	return initDoneTempl.Execute(out, ctx)
 }
 
-// createClient creates a clientset.Interface object
-func createClient(cfg *kubeadmapi.InitConfiguration, dryRun bool) (clientset.Interface, error) {
-	if dryRun {
-		// If we're dry-running; we should create a faked client that answers some GETs in order to be able to do the full init flow and just logs the rest of requests
-		dryRunGetter := apiclient.NewInitDryRunGetter(cfg.NodeRegistration.Name, cfg.Networking.ServiceSubnet)
-		return apiclient.NewDryRunClient(dryRunGetter, os.Stdout), nil
-	}
-
-	// If we're acting for real, we should create a connection to the API server and wait for it to come up
-	return kubeconfigutil.ClientSetFromFile(kubeadmconstants.GetAdminKubeConfigPath())
-}
-
 // getDirectoriesToUse returns the (in order) certificates, kubeconfig and Static Pod manifest directories, followed by a possible error
 // This behaves differently when dry-running vs the normal flow
 func getDirectoriesToUse(dryRun bool, dryRunDir string, defaultPkiDir string) (string, string, string, string, error) {
@@ -616,67 +595,3 @@ func getDirectoriesToUse(dryRun bool, dryRunDir string, defaultPkiDir string) (s
 
 	return defaultPkiDir, kubeadmconstants.KubernetesDir, kubeadmconstants.GetStaticPodDirectory(), kubeadmconstants.KubeletRunDirectory, nil
 }
-
-// printFilesIfDryRunning prints the Static Pod manifests to stdout and informs about the temporary directory to go and lookup
-func printFilesIfDryRunning(dryRun bool, manifestDir string) error {
-	if !dryRun {
-		return nil
-	}
-
-	fmt.Printf("[dryrun] wrote certificates, kubeconfig files and control plane manifests to the %q directory\n", manifestDir)
-	fmt.Println("[dryrun] the certificates or kubeconfig files would not be printed due to their sensitive nature")
-	fmt.Printf("[dryrun] please examine the %q directory for details about what would be written\n", manifestDir)
-
-	// Print the contents of the upgraded manifests and pretend like they were in /etc/kubernetes/manifests
-	files := []dryrunutil.FileToPrint{}
-	// Print static pod manifests
-	for _, component := range kubeadmconstants.MasterComponents {
-		realPath := kubeadmconstants.GetStaticPodFilepath(component, manifestDir)
-		outputPath := kubeadmconstants.GetStaticPodFilepath(component, kubeadmconstants.GetStaticPodDirectory())
-		files = append(files, dryrunutil.NewFileToPrint(realPath, outputPath))
-	}
-	// Print kubelet config manifests
-	kubeletConfigFiles := []string{kubeadmconstants.KubeletConfigurationFileName, kubeadmconstants.KubeletEnvFileName}
-	for _, filename := range kubeletConfigFiles {
-		realPath := filepath.Join(manifestDir, filename)
-		outputPath := filepath.Join(kubeadmconstants.KubeletRunDirectory, filename)
-		files = append(files, dryrunutil.NewFileToPrint(realPath, outputPath))
-	}
-
-	return dryrunutil.PrintDryRunFiles(files, os.Stdout)
-}
-
-// getWaiter gets the right waiter implementation for the right occasion
-func getWaiter(ctx *initData, client clientset.Interface) apiclient.Waiter {
-	if ctx.dryRun {
-		return dryrunutil.NewWaiter()
-	}
-
-	// We know that the images should be cached locally already as we have pulled them using
-	// crictl in the preflight checks. Hence we can have a pretty short timeout for the kubelet
-	// to start creating Static Pods.
-	timeout := 4 * time.Minute
-	return apiclient.NewKubeWaiter(client, timeout, os.Stdout)
-}
-
-// waitForKubeletAndFunc waits primarily for the function f to execute, even though it might take some time. If that takes a long time, and the kubelet
-// /healthz continuously are unhealthy, kubeadm will error out after a period of exponential backoff
-func waitForKubeletAndFunc(waiter apiclient.Waiter, f func() error) error {
-	errorChan := make(chan error)
-
-	go func(errC chan error, waiter apiclient.Waiter) {
-		// This goroutine can only make kubeadm init fail. If this check succeeds, it won't do anything special
-		if err := waiter.WaitForHealthyKubelet(40*time.Second, fmt.Sprintf("http://localhost:%d/healthz", kubeadmconstants.KubeletHealthzPort)); err != nil {
-			errC <- err
-		}
-	}(errorChan, waiter)
-
-	go func(errC chan error, waiter apiclient.Waiter) {
-		// This main goroutine sends whatever the f function returns (error or not) to the channel
-		// This in order to continue on success (nil error), or just fail if the function returns an error
-		errC <- f()
-	}(errorChan, waiter)
-
-	// This call is blocking until one of the goroutines sends to errorChan
-	return <-errorChan
-}

cmd/kubeadm/app/cmd/join.go

@@ -548,7 +548,7 @@ func (j *Join) BootstrapKubelet(tlsBootstrapCfg *clientcmdapi.Config) error {
 	// 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, kubeadmconstants.TLSBootstrapTimeout, os.Stdout)
-	if err := waitForKubeletAndFunc(waiter, waitForTLSBootstrappedClient); err != nil {
+	if err := waiter.WaitForKubeletAndFunc(waitForTLSBootstrappedClient); err != nil {
 		fmt.Printf(kubeadmJoinFailMsg, err)
 		return err
 	}

cmd/kubeadm/app/cmd/phases/BUILD

@@ -15,6 +15,7 @@ go_library(
         "selfhosting.go",
         "uploadconfig.go",
         "util.go",
+        "waitcontrolplane.go",
     ],
     importpath = "k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases",
     visibility = ["//visibility:public"],
@@ -46,6 +47,7 @@ go_library(
         "//cmd/kubeadm/app/util/apiclient:go_default_library",
         "//cmd/kubeadm/app/util/audit:go_default_library",
         "//cmd/kubeadm/app/util/config:go_default_library",
+        "//cmd/kubeadm/app/util/dryrun:go_default_library",
         "//cmd/kubeadm/app/util/kubeconfig:go_default_library",
         "//pkg/util/normalizer:go_default_library",
         "//pkg/version:go_default_library",
@@ -55,6 +57,7 @@ go_library(
         "//staging/src/k8s.io/cluster-bootstrap/token/api:go_default_library",
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/github.com/pkg/errors:go_default_library",
+        "//vendor/github.com/renstrom/dedent:go_default_library",
         "//vendor/github.com/spf13/cobra:go_default_library",
         "//vendor/github.com/spf13/pflag:go_default_library",
         "//vendor/k8s.io/utils/exec:go_default_library",

cmd/kubeadm/app/cmd/phases/controlplane.go

@@ -129,7 +129,7 @@ func runControlPlaneSubPhase(component string) func(c workflow.RunData) error {
 			}
 		}
 
-		fmt.Printf("[control-plane] creating static Pod manifest for %q\n", component)
+		fmt.Printf("[control-plane] Creating static Pod manifest for %q\n", component)
 		if err := controlplane.CreateStaticPodFiles(data.ManifestDir(), cfg, component); err != nil {
 			return err
 		}

cmd/kubeadm/app/cmd/phases/waitcontrolplane.go

@@ -0,0 +1,156 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 phases
+
+import (
+	"fmt"
+	"io"
+	"path/filepath"
+	"text/template"
+	"time"
+
+	"github.com/golang/glog"
+	"github.com/pkg/errors"
+	"github.com/renstrom/dedent"
+	clientset "k8s.io/client-go/kubernetes"
+	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
+	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
+	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
+	"k8s.io/kubernetes/cmd/kubeadm/app/util/apiclient"
+	dryrunutil "k8s.io/kubernetes/cmd/kubeadm/app/util/dryrun"
+)
+
+var (
+	kubeletFailTempl = template.Must(template.New("init").Parse(dedent.Dedent(`
+	Unfortunately, an error has occurred:
+		{{ .Error }}
+
+	This error is likely caused by:
+		- The kubelet is not running
+		- The kubelet is unhealthy due to a misconfiguration of the node in some way (required cgroups disabled)
+
+	If you are on a systemd-powered system, you can try to troubleshoot the error with the following commands:
+		- 'systemctl status kubelet'
+		- 'journalctl -xeu kubelet'
+
+	Additionally, a control plane component may have crashed or exited when started by the container runtime.
+	To troubleshoot, list all containers using your preferred container runtimes CLI, e.g. docker.
+	Here is one example how you may list all Kubernetes containers running in docker:
+		- 'docker ps -a | grep kube | grep -v pause'
+		Once you have found the failing container, you can inspect its logs with:
+		- 'docker logs CONTAINERID'
+	`)))
+)
+
+type waitControlPlaneData interface {
+	Cfg() *kubeadmapi.InitConfiguration
+	ManifestDir() string
+	DryRun() bool
+	Client() (clientset.Interface, error)
+	OutputWriter() io.Writer
+}
+
+// NewWaitControlPlanePhase is a hidden phase that runs after the control-plane and etcd phases
+func NewWaitControlPlanePhase() workflow.Phase {
+	phase := workflow.Phase{
+		Name:   "wait-control-plane",
+		Run:    runWaitControlPlanePhase,
+		Hidden: true,
+	}
+	return phase
+}
+
+func runWaitControlPlanePhase(c workflow.RunData) error {
+	data, ok := c.(waitControlPlaneData)
+	if !ok {
+		return errors.New("wait-control-plane phase invoked with an invalid data struct")
+	}
+
+	// If we're dry-running, print the generated manifests
+	if err := printFilesIfDryRunning(data); err != nil {
+		return errors.Wrap(err, "error printing files on dryrun")
+	}
+
+	// waiter holds the apiclient.Waiter implementation of choice, responsible for querying the API server in various ways and waiting for conditions to be fulfilled
+	glog.V(1).Infof("[wait-control-plane] Waiting for the API server to be healthy")
+
+	client, err := data.Client()
+	if err != nil {
+		return errors.Wrap(err, "cannot obtain client")
+	}
+
+	waiter, err := NewControlPlaneWaiter(data.DryRun(), client, data.OutputWriter())
+	if err != nil {
+		return errors.Wrap(err, "error creating waiter")
+	}
+
+	fmt.Printf("[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory %q\n", data.ManifestDir())
+
+	if err := waiter.WaitForKubeletAndFunc(waiter.WaitForAPI); err != nil {
+		ctx := map[string]string{
+			"Error": fmt.Sprintf("%v", err),
+		}
+		kubeletFailTempl.Execute(data.OutputWriter(), ctx)
+		return errors.New("couldn't initialize a Kubernetes cluster")
+	}
+
+	return nil
+}
+
+// printFilesIfDryRunning prints the Static Pod manifests to stdout and informs about the temporary directory to go and lookup
+func printFilesIfDryRunning(data waitControlPlaneData) error {
+	if !data.DryRun() {
+		return nil
+	}
+	manifestDir := data.ManifestDir()
+
+	fmt.Printf("[dryrun] Wrote certificates, kubeconfig files and control plane manifests to the %q directory\n", manifestDir)
+	fmt.Println("[dryrun] The certificates or kubeconfig files would not be printed due to their sensitive nature")
+	fmt.Printf("[dryrun] Please examine the %q directory for details about what would be written\n", manifestDir)
+
+	// Print the contents of the upgraded manifests and pretend like they were in /etc/kubernetes/manifests
+	files := []dryrunutil.FileToPrint{}
+	// Print static pod manifests
+	for _, component := range kubeadmconstants.MasterComponents {
+		realPath := kubeadmconstants.GetStaticPodFilepath(component, manifestDir)
+		outputPath := kubeadmconstants.GetStaticPodFilepath(component, kubeadmconstants.GetStaticPodDirectory())
+		files = append(files, dryrunutil.NewFileToPrint(realPath, outputPath))
+	}
+	// Print kubelet config manifests
+	kubeletConfigFiles := []string{kubeadmconstants.KubeletConfigurationFileName, kubeadmconstants.KubeletEnvFileName}
+	for _, filename := range kubeletConfigFiles {
+		realPath := filepath.Join(manifestDir, filename)
+		outputPath := filepath.Join(kubeadmconstants.KubeletRunDirectory, filename)
+		files = append(files, dryrunutil.NewFileToPrint(realPath, outputPath))
+	}
+
+	return dryrunutil.PrintDryRunFiles(files, data.OutputWriter())
+}
+
+// NewControlPlaneWaiter returns a new waiter that is used to wait on the control plane to boot up.
+// TODO: make private (lowercase) after self-hosting phase is removed.
+func NewControlPlaneWaiter(dryRun bool, client clientset.Interface, out io.Writer) (apiclient.Waiter, error) {
+	if dryRun {
+		return dryrunutil.NewWaiter(), nil
+	}
+
+	// We know that the images should be cached locally already as we have pulled them using
+	// crictl in the preflight checks. Hence we can have a pretty short timeout for the kubelet
+	// to start creating Static Pods.
+	timeout := 4 * time.Minute
+	return apiclient.NewKubeWaiter(client, timeout, out), nil
+}

cmd/kubeadm/app/phases/upgrade/staticpods_test.go

@@ -135,6 +135,11 @@ func (w *fakeWaiter) WaitForHealthyKubelet(_ time.Duration, _ string) error {
 	return nil
 }
 
+// WaitForKubeletAndFunc is a wrapper for WaitForHealthyKubelet that also blocks for a function
+func (w *fakeWaiter) WaitForKubeletAndFunc(f func() error) error {
+	return nil
+}
+
 type fakeStaticPodPathManager struct {
 	kubernetesDir     string
 	realManifestDir   string

cmd/kubeadm/app/util/apiclient/wait.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2017 The Kubernetes Authors.
+Copyright 2018 The Kubernetes Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -30,6 +30,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/wait"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/kubernetes/cmd/kubeadm/app/constants"
+	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
 	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
 )
 
@@ -50,6 +51,8 @@ type Waiter interface {
 	WaitForStaticPodControlPlaneHashes(nodeName string) (map[string]string, error)
 	// WaitForHealthyKubelet blocks until the kubelet /healthz endpoint returns 'ok'
 	WaitForHealthyKubelet(initalTimeout time.Duration, healthzEndpoint string) error
+	// WaitForKubeletAndFunc is a wrapper for WaitForHealthyKubelet that also blocks for a function
+	WaitForKubeletAndFunc(f func() error) error
 	// SetTimeout adjusts the timeout to the specified duration
 	SetTimeout(timeout time.Duration)
 }
@@ -132,17 +135,18 @@ func (w *KubeWaiter) WaitForPodToDisappear(podName string) error {
 // WaitForHealthyKubelet blocks until the kubelet /healthz endpoint returns 'ok'
 func (w *KubeWaiter) WaitForHealthyKubelet(initalTimeout time.Duration, healthzEndpoint string) error {
 	time.Sleep(initalTimeout)
+	fmt.Printf("[kubelet-check] Initial timeout of %v passed.\n", initalTimeout)
 	return TryRunCommand(func() error {
 		client := &http.Client{Transport: netutil.SetOldTransportDefaults(&http.Transport{})}
 		resp, err := client.Get(healthzEndpoint)
 		if err != nil {
-			fmt.Printf("[kubelet-check] It seems like the kubelet isn't running or healthy.\n")
+			fmt.Println("[kubelet-check] It seems like the kubelet isn't running or healthy.")
 			fmt.Printf("[kubelet-check] The HTTP call equal to 'curl -sSL %s' failed with error: %v.\n", healthzEndpoint, err)
 			return err
 		}
 		defer resp.Body.Close()
 		if resp.StatusCode != http.StatusOK {
-			fmt.Printf("[kubelet-check] It seems like the kubelet isn't running or healthy.")
+			fmt.Println("[kubelet-check] It seems like the kubelet isn't running or healthy.")
 			fmt.Printf("[kubelet-check] The HTTP call equal to 'curl -sSL %s' returned HTTP code %d\n", healthzEndpoint, resp.StatusCode)
 			return errors.New("the kubelet healthz endpoint is unhealthy")
 		}
@@ -150,6 +154,27 @@ func (w *KubeWaiter) WaitForHealthyKubelet(initalTimeout time.Duration, healthzE
 	}, 5) // a failureThreshold of five means waiting for a total of 155 seconds
 }
 
+// WaitForKubeletAndFunc waits primarily for the function f to execute, even though it might take some time. If that takes a long time, and the kubelet
+// /healthz continuously are unhealthy, kubeadm will error out after a period of exponential backoff
+func (w *KubeWaiter) WaitForKubeletAndFunc(f func() error) error {
+	errorChan := make(chan error)
+
+	go func(errC chan error, waiter Waiter) {
+		if err := waiter.WaitForHealthyKubelet(40*time.Second, fmt.Sprintf("http://localhost:%d/healthz", kubeadmconstants.KubeletHealthzPort)); err != nil {
+			errC <- err
+		}
+	}(errorChan, w)
+
+	go func(errC chan error, waiter Waiter) {
+		// This main goroutine sends whatever the f function returns (error or not) to the channel
+		// This in order to continue on success (nil error), or just fail if the function returns an error
+		errC <- f()
+	}(errorChan, w)
+
+	// This call is blocking until one of the goroutines sends to errorChan
+	return <-errorChan
+}
+
 // SetTimeout adjusts the timeout to the specified duration
 func (w *KubeWaiter) SetTimeout(timeout time.Duration) {
 	w.timeout = timeout

cmd/kubeadm/app/util/dryrun/dryrun.go

@@ -111,6 +111,11 @@ func (w *Waiter) WaitForHealthyKubelet(_ time.Duration, healthzEndpoint string)
 	return nil
 }
 
+// WaitForKubeletAndFunc is a wrapper for WaitForHealthyKubelet that also blocks for a function
+func (w *Waiter) WaitForKubeletAndFunc(f func() error) error {
+	return nil
+}
+
 // SetTimeout is a no-op; we don't wait in this implementation
 func (w *Waiter) SetTimeout(_ time.Duration) {}
 

docs/.generated_docs

@@ -80,6 +80,7 @@ docs/admin/kubeadm_init_phase_kubeconfig_kubelet.md
 docs/admin/kubeadm_init_phase_kubeconfig_scheduler.md
 docs/admin/kubeadm_init_phase_kubelet-start.md
 docs/admin/kubeadm_init_phase_preflight.md
+docs/admin/kubeadm_init_phase_wait-control-plane.md
 docs/admin/kubeadm_join.md
 docs/admin/kubeadm_reset.md
 docs/admin/kubeadm_token.md
@@ -175,6 +176,7 @@ docs/man/man1/kubeadm-init-phase-kubeconfig-scheduler.1
 docs/man/man1/kubeadm-init-phase-kubeconfig.1
 docs/man/man1/kubeadm-init-phase-kubelet-start.1
 docs/man/man1/kubeadm-init-phase-preflight.1
+docs/man/man1/kubeadm-init-phase-wait-control-plane.1
 docs/man/man1/kubeadm-init-phase.1
 docs/man/man1/kubeadm-init.1
 docs/man/man1/kubeadm-join.1

docs/admin/kubeadm_init_phase_wait-control-plane.md

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.

docs/man/man1/kubeadm-init-phase-wait-control-plane.1

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.