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Merge pull request #121958 from neolit123/1.30-remove-kubelet-and-func

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kubeadm: drop concurrency when waiting for kubelet /healthz
This commit is contained in:
Kubernetes Prow Robot 2023-12-25 15:52:25 +01:00 committed by GitHub
commit a56093db9f
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7 changed files with 117 additions and 104 deletions
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27
cmd/kubeadm/app/cmd/phases/init/waitcontrolplane.go
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@ -26,9 +26,9 @@ import (
"github.com/pkg/errors"
clientset "k8s.io/client-go/kubernetes"
"k8s.io/klog/v2"
"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"
)
@ -79,24 +79,23 @@ func runWaitControlPlanePhase(c workflow.RunData) error {
}
}
// waiter holds the apiclient.Waiter implementation of choice, responsible for querying the API server in various ways and waiting for conditions to be fulfilled
klog.V(1).Infoln("[wait-control-plane] Waiting for the API server to be healthy")
// WaitForAPI uses the /healthz endpoint, thus a client without permissions works fine
// Both Wait* calls below use a /healthz endpoint, thus a client without permissions works fine
client, err := data.ClientWithoutBootstrap()
if err != nil {
return errors.Wrap(err, "cannot obtain client without bootstrap")
}
timeout := data.Cfg().ClusterConfiguration.APIServer.TimeoutForControlPlane.Duration
waiter, err := newControlPlaneWaiter(data.DryRun(), timeout, client, data.OutputWriter())
waiter, err := newControlPlaneWaiter(data.DryRun(), 0, 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. This can take up to %v\n", data.ManifestDir(), timeout)
controlPlaneTimeout := data.Cfg().ClusterConfiguration.APIServer.TimeoutForControlPlane.Duration
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 {
handleError := func(err error) error {
context := struct {
Error string
Socket string
@ -109,6 +108,16 @@ func runWaitControlPlanePhase(c workflow.RunData) error {
return errors.New("couldn't initialize a Kubernetes cluster")
}
waiter.SetTimeout(kubeadmconstants.DefaultKubeletTimeout)
if err := waiter.WaitForKubelet(); err != nil {
return handleError(err)
}
waiter.SetTimeout(controlPlaneTimeout)
if err := waiter.WaitForAPI(); err != nil {
return handleError(err)
}
return nil
}

12
cmd/kubeadm/app/cmd/phases/join/kubelet.go
View File

@ -205,8 +205,14 @@ func runKubeletStartJoinPhase(c workflow.RunData) (returnErr error) {
// 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, kubeadmconstants.TLSBootstrapTimeout, os.Stdout)
if err := waiter.WaitForKubeletAndFunc(waitForTLSBootstrappedClient); err != nil {
waiter := apiclient.NewKubeWaiter(nil, 0, os.Stdout)
waiter.SetTimeout(kubeadmconstants.DefaultKubeletTimeout)
if err := waiter.WaitForKubelet(); err != nil {
fmt.Printf(kubeadmJoinFailMsg, err)
return err
}
if err := waitForTLSBootstrappedClient(); err != nil {
fmt.Printf(kubeadmJoinFailMsg, err)
return err
}
@ -227,7 +233,7 @@ func runKubeletStartJoinPhase(c workflow.RunData) (returnErr error) {
// waitForTLSBootstrappedClient waits for the /etc/kubernetes/kubelet.conf file to be available
func waitForTLSBootstrappedClient() error {
fmt.Println("[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...")
fmt.Println("[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap")
// Loop on every falsy return. Return with an error if raised. Exit successfully if true is returned.
return wait.PollImmediate(kubeadmconstants.TLSBootstrapRetryInterval, kubeadmconstants.TLSBootstrapTimeout, func() (bool, error) {

2
cmd/kubeadm/app/constants/constants.go
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@ -230,6 +230,8 @@ const (
// DefaultControlPlaneTimeout specifies the default control plane (actually API Server) timeout for use by kubeadm
DefaultControlPlaneTimeout = 4 * time.Minute
// DefaultKubeletTimeout specifies the default kubelet timeout
DefaultKubeletTimeout = 4 * time.Minute
// MinimumAddressesInServiceSubnet defines minimum amount of nodes the Service subnet should allow.
// We need at least ten, because the DNS service is always at the tenth cluster clusterIP

24
cmd/kubeadm/app/phases/bootstraptoken/node/token.go
View File

@ -22,10 +22,12 @@ import (
"github.com/pkg/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/wait"
clientset "k8s.io/client-go/kubernetes"
bootstraputil "k8s.io/cluster-bootstrap/token/util"
bootstraptokenv1 "k8s.io/kubernetes/cmd/kubeadm/app/apis/bootstraptoken/v1"
kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
"k8s.io/kubernetes/cmd/kubeadm/app/util/apiclient"
)
@ -46,15 +48,21 @@ func UpdateOrCreateTokens(client clientset.Interface, failIfExists bool, tokens
}
updatedOrNewSecret := bootstraptokenv1.BootstrapTokenToSecret(&token)
// Try to create or update the token with an exponential backoff
err = apiclient.TryRunCommand(func() error {
if err := apiclient.CreateOrUpdateSecret(client, updatedOrNewSecret); err != nil {
return errors.Wrapf(err, "failed to create or update bootstrap token with name %s", secretName)
}
return nil
}, 5)
var lastError error
err = wait.PollUntilContextTimeout(
context.Background(),
kubeadmconstants.APICallRetryInterval,
kubeadmconstants.APICallWithWriteTimeout,
true, func(_ context.Context) (bool, error) {
if err := apiclient.CreateOrUpdateSecret(client, updatedOrNewSecret); err != nil {
lastError = errors.Wrapf(err, "failed to create or update bootstrap token with name %s", secretName)
return false, nil
}
return true, nil
})
if err != nil {
return err
return lastError
}
}
return nil

9
cmd/kubeadm/app/phases/upgrade/staticpods_test.go
View File

@ -131,13 +131,8 @@ func (w *fakeWaiter) WaitForStaticPodHashChange(_, _, _ string) error {
return w.errsToReturn[waitForHashChange]
}
// WaitForHealthyKubelet returns a dummy nil just to implement the interface
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 {
// WaitForHKubelet returns a dummy nil just to implement the interface
func (w *fakeWaiter) WaitForKubelet() error {
return nil
}

136
cmd/kubeadm/app/util/apiclient/wait.go
View File

@ -50,10 +50,8 @@ type Waiter interface {
WaitForStaticPodHashChange(nodeName, component, previousHash string) error
// WaitForStaticPodControlPlaneHashes fetches sha256 hashes for the control plane static pods
WaitForStaticPodControlPlaneHashes(nodeName string) (map[string]string, error)
// WaitForHealthyKubelet blocks until the kubelet /healthz endpoint returns 'ok'
WaitForHealthyKubelet(initialTimeout time.Duration, healthzEndpoint string) error
// WaitForKubeletAndFunc is a wrapper for WaitForHealthyKubelet that also blocks for a function
WaitForKubeletAndFunc(f func() error) error
// WaitForKubelet blocks until the kubelet /healthz endpoint returns 'ok'
WaitForKubelet() error
// SetTimeout adjusts the timeout to the specified duration
SetTimeout(timeout time.Duration)
}
@ -76,17 +74,28 @@ func NewKubeWaiter(client clientset.Interface, timeout time.Duration, writer io.
// WaitForAPI waits for the API Server's /healthz endpoint to report "ok"
func (w *KubeWaiter) WaitForAPI() error {
start := time.Now()
return wait.PollImmediate(kubeadmconstants.APICallRetryInterval, w.timeout, func() (bool, error) {
healthStatus := 0
w.client.Discovery().RESTClient().Get().AbsPath("/healthz").Do(context.TODO()).StatusCode(&healthStatus)
if healthStatus != http.StatusOK {
return false, nil
}
fmt.Printf("[api-check] Waiting for a healthy API server. This can take up to %v\n", w.timeout)
fmt.Printf("[apiclient] All control plane components are healthy after %f seconds\n", time.Since(start).Seconds())
return true, nil
})
start := time.Now()
err := wait.PollUntilContextTimeout(
context.Background(),
kubeadmconstants.APICallRetryInterval,
w.timeout,
true, func(ctx context.Context) (bool, error) {
healthStatus := 0
w.client.Discovery().RESTClient().Get().AbsPath("/healthz").Do(ctx).StatusCode(&healthStatus)
if healthStatus != http.StatusOK {
return false, nil
}
return true, nil
})
if err != nil {
fmt.Printf("[api-check] The API server is not healthy after %v\n", time.Since(start))
return err
}
fmt.Printf("[api-check] The API server is healthy after %v\n", time.Since(start))
return nil
}
// WaitForPodsWithLabel will lookup pods with the given label and wait until they are all
@ -133,47 +142,54 @@ func (w *KubeWaiter) WaitForPodToDisappear(podName string) error {
})
}
// WaitForHealthyKubelet blocks until the kubelet /healthz endpoint returns 'ok'
func (w *KubeWaiter) WaitForHealthyKubelet(initialTimeout time.Duration, healthzEndpoint string) error {
time.Sleep(initialTimeout)
fmt.Printf("[kubelet-check] Initial timeout of %v passed.\n", initialTimeout)
return TryRunCommand(func() error {
client := &http.Client{Transport: netutil.SetOldTransportDefaults(&http.Transport{})}
resp, err := client.Get(healthzEndpoint)
if err != nil {
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.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")
}
return nil
}, 5) // a failureThreshold of five means waiting for a total of 155 seconds
}
// WaitForKubelet blocks until the kubelet /healthz endpoint returns 'ok'.
func (w *KubeWaiter) WaitForKubelet() error {
var (
lastError error
start = time.Now()
healthzEndpoint = fmt.Sprintf("http://localhost:%d/healthz", kubeadmconstants.KubeletHealthzPort)
)
// 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, 1)
fmt.Printf("[kubelet-check] Waiting for a healthy kubelet. This can take up to %v\n", w.timeout)
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)
formatError := func(cause string) error {
return errors.Errorf("The HTTP call equal to 'curl -sSL %s' returned %s\n",
healthzEndpoint, cause)
}
go func(errC chan error) {
// 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)
err := wait.PollUntilContextTimeout(
context.Background(),
kubeadmconstants.APICallRetryInterval,
w.timeout,
true, func(ctx context.Context) (bool, error) {
client := &http.Client{Transport: netutil.SetOldTransportDefaults(&http.Transport{})}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, healthzEndpoint, nil)
if err != nil {
lastError = formatError(fmt.Sprintf("error: %v", err))
return false, err
}
resp, err := client.Do(req)
if err != nil {
lastError = formatError(fmt.Sprintf("error: %v", err))
return false, nil
}
defer func() {
_ = resp.Body.Close()
}()
if resp.StatusCode != http.StatusOK {
lastError = formatError(fmt.Sprintf("status code: %d", resp.StatusCode))
return false, nil
}
// This call is blocking until one of the goroutines sends to errorChan
return <-errorChan
return true, nil
})
if err != nil {
fmt.Printf("[kubelet-check] The kubelet is not healthy after %v\n", time.Since(start))
return lastError
}
fmt.Printf("[kubelet-check] The kubelet is healthy after %v\n", time.Since(start))
return nil
}
// SetTimeout adjusts the timeout to the specified duration
@ -264,21 +280,3 @@ func getStaticPodSingleHash(client clientset.Interface, nodeName string, compone
staticPodHash := staticPod.Annotations["kubernetes.io/config.hash"]
return staticPodHash, nil
}
// TryRunCommand runs a function a maximum of failureThreshold times, and retries on error. If failureThreshold is hit; the last error is returned
func TryRunCommand(f func() error, failureThreshold int) error {
backoff := wait.Backoff{
Duration: 5 * time.Second,
Factor: 2, // double the timeout for every failure
Steps: failureThreshold,
}
return wait.ExponentialBackoff(backoff, func() (bool, error) {
err := f()
if err != nil {
// Retry until the timeout
return false, nil
}
// The last f() call was a success, return cleanly
return true, nil
})
}

11
cmd/kubeadm/app/util/dryrun/dryrun.go
View File

@ -106,14 +106,9 @@ func (w *Waiter) WaitForPodToDisappear(podName string) error {
return nil
}
// WaitForHealthyKubelet blocks until the kubelet /healthz endpoint returns 'ok'
func (w *Waiter) WaitForHealthyKubelet(_ time.Duration, healthzEndpoint string) error {
fmt.Printf("[dryrun] Would make sure the kubelet %q endpoint is healthy\n", healthzEndpoint)
return nil
}
// WaitForKubeletAndFunc is a wrapper for WaitForHealthyKubelet that also blocks for a function
func (w *Waiter) WaitForKubeletAndFunc(f func() error) error {
// WaitForKubelet blocks until the kubelet /healthz endpoint returns 'ok'
func (w *Waiter) WaitForKubelet() error {
fmt.Println("[dryrun] Would make sure the kubelet's /healthz endpoint is healthy")
return nil
}