kubeadm: cleanup after ControlPlaneKubeletLocalMode

cmd/kubeadm/app/cmd/phases/init/kubeconfig.go

@@ -24,7 +24,6 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
 	kubeadmconstants "k8s.io/kubernetes/cmd/kubeadm/app/constants"
-	"k8s.io/kubernetes/cmd/kubeadm/app/features"
 	kubeconfigphase "k8s.io/kubernetes/cmd/kubeadm/app/phases/kubeconfig"
 	kubeadmutil "k8s.io/kubernetes/cmd/kubeadm/app/util"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
@@ -158,11 +157,9 @@ func runKubeConfigFile(kubeConfigFileName string) func(workflow.RunData) error {
 
 		initConfiguration := data.Cfg().DeepCopy()
 
-		if features.Enabled(cfg.FeatureGates, features.ControlPlaneKubeletLocalMode) {
-			if kubeConfigFileName == kubeadmconstants.KubeletKubeConfigFileName {
-				// Unset the ControlPlaneEndpoint so the creation falls back to the LocalAPIEndpoint for the kubelet's kubeconfig.
-				initConfiguration.ControlPlaneEndpoint = ""
-			}
+		if kubeConfigFileName == kubeadmconstants.KubeletKubeConfigFileName {
+			// Unset the ControlPlaneEndpoint so the creation falls back to the LocalAPIEndpoint for the kubelet's kubeconfig.
+			initConfiguration.ControlPlaneEndpoint = ""
 		}
 
 		// creates the KubeConfig file (or use existing)

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

@@ -24,7 +24,6 @@ import (
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
 	cmdutil "k8s.io/kubernetes/cmd/kubeadm/app/cmd/util"
-	"k8s.io/kubernetes/cmd/kubeadm/app/features"
 	etcdphase "k8s.io/kubernetes/cmd/kubeadm/app/phases/etcd"
 	markcontrolplanephase "k8s.io/kubernetes/cmd/kubeadm/app/phases/markcontrolplane"
 	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
@@ -83,32 +82,26 @@ func NewControlPlaneJoinPhase() workflow.Phase {
 func NewEtcdJoinPhase() workflow.Phase {
 	return workflow.Phase{
 		Name:          "etcd-join",
-		Short:         fmt.Sprintf("[EXPERIMENTAL] Join etcd for control plane nodes (only used when feature gate %s is enabled)", features.ControlPlaneKubeletLocalMode),
+		Short:         "Join etcd for control plane nodes",
 		Run:           runEtcdPhase,
 		Example:       etcdJoinExample,
 		InheritFlags:  getControlPlaneJoinPhaseFlags("etcd"),
 		ArgsValidator: cobra.NoArgs,
-		// TODO: unhide this phase once ControlPlaneKubeletLocalMode goes GA:
-		// https://github.com/kubernetes/enhancements/issues/4471
-		Hidden: true,
-		// Only run this phase as if `ControlPlaneKubeletLocalMode` is activated.
-		RunIf: func(c workflow.RunData) (bool, error) {
-			return checkFeatureState(c, features.ControlPlaneKubeletLocalMode, true)
-		},
 	}
 }
 
+// TODO: Deprecated. Remove once ControlPlaneKubeletLocalMode is removed in 1.36.
+// https://github.com/kubernetes/kubeadm/issues/2271
 func newEtcdLocalSubphase() workflow.Phase {
 	return workflow.Phase{
 		Name:          "etcd",
-		Short:         "Add a new local etcd member",
+		Short:         "[DEPRECATED] Add a new local etcd member. Deprecated in favor of 'etcd-join' and will be removed in 1.36",
 		Run:           runEtcdPhase,
 		InheritFlags:  getControlPlaneJoinPhaseFlags("etcd"),
 		ArgsValidator: cobra.NoArgs,
-		// Only run this phase as subphase of control-plane-join phase if
-		// `ControlPlaneKubeletLocalMode` is deactivated.
+		Hidden:        true,
 		RunIf: func(c workflow.RunData) (bool, error) {
-			return checkFeatureState(c, features.ControlPlaneKubeletLocalMode, false)
+			return false, nil
 		},
 	}
 }

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

@@ -25,9 +25,6 @@ import (
 	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
 
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
-	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/phases/workflow"
-	"k8s.io/kubernetes/cmd/kubeadm/app/features"
-	"k8s.io/kubernetes/cmd/kubeadm/app/util/errors"
 )
 
 // JoinData is the interface to use for join phases.
@@ -47,17 +44,3 @@ type JoinData interface {
 	ManifestDir() string
 	CertificateWriteDir() string
 }
-
-func checkFeatureState(c workflow.RunData, featureGate string, state bool) (bool, error) {
-	data, ok := c.(JoinData)
-	if !ok {
-		return false, errors.New("control-plane-join phase invoked with an invalid data struct")
-	}
-
-	cfg, err := data.InitCfg()
-	if err != nil {
-		return false, err
-	}
-
-	return state == features.Enabled(cfg.FeatureGates, featureGate), nil
-}

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

@@ -75,20 +75,13 @@ func NewKubeletStartPhase() workflow.Phase {
 func NewKubeletWaitBootstrapPhase() workflow.Phase {
 	return workflow.Phase{
 		Name:  "kubelet-wait-bootstrap",
-		Short: "[EXPERIMENTAL] Wait for the kubelet to bootstrap itself (only used when feature gate ControlPlaneKubeletLocalMode is enabled)",
+		Short: "Wait for the kubelet to bootstrap itself",
 		Run:   runKubeletWaitBootstrapPhase,
 		InheritFlags: []string{
 			options.CfgPath,
 			options.NodeCRISocket,
 			options.DryRun,
 		},
-		// TODO: unhide this phase once ControlPlaneKubeletLocalMode goes GA:
-		// https://github.com/kubernetes/enhancements/issues/4471
-		Hidden: true,
-		// Only run this phase as if `ControlPlaneKubeletLocalMode` is activated.
-		RunIf: func(c workflow.RunData) (bool, error) {
-			return checkFeatureState(c, features.ControlPlaneKubeletLocalMode, true)
-		},
 	}
 }
 
@@ -124,16 +117,6 @@ func runKubeletStartJoinPhase(c workflow.RunData) (returnErr error) {
 	}
 	bootstrapKubeConfigFile := filepath.Join(data.KubeConfigDir(), kubeadmconstants.KubeletBootstrapKubeConfigFileName)
 
-	// Do not delete the bootstrapKubeConfigFile at the end of this function when
-	// using ControlPlaneKubeletLocalMode. The KubeletWaitBootstrapPhase will delete
-	// it when the feature is enabled.
-	if !features.Enabled(initCfg.FeatureGates, features.ControlPlaneKubeletLocalMode) {
-		// Deletes the bootstrapKubeConfigFile, so the credential used for TLS bootstrap is removed from disk
-		defer func() {
-			_ = os.Remove(bootstrapKubeConfigFile)
-		}()
-	}
-
 	var client clientset.Interface
 	// If dry-use the client from joinData, else create a new bootstrap client
 	if data.DryRun() {
@@ -148,17 +131,15 @@ func runKubeletStartJoinPhase(c workflow.RunData) (returnErr error) {
 		}
 	}
 
-	if features.Enabled(initCfg.FeatureGates, features.ControlPlaneKubeletLocalMode) {
-		// Set the server url to LocalAPIEndpoint if the feature gate is enabled so the config
-		// which gets passed to the kubelet forces it to talk to the local kube-apiserver.
-		if cfg.ControlPlane != nil {
-			for c, conf := range tlsBootstrapCfg.Clusters {
-				conf.Server, err = kubeadmutil.GetLocalAPIEndpoint(&cfg.ControlPlane.LocalAPIEndpoint)
-				if err != nil {
-					return errors.Wrapf(err, "could not get LocalAPIEndpoint when %s is enabled", features.ControlPlaneKubeletLocalMode)
-				}
-				tlsBootstrapCfg.Clusters[c] = conf
+	// Set the server url to LocalAPIEndpoint if the feature gate is enabled so the config
+	// which gets passed to the kubelet forces it to talk to the local kube-apiserver.
+	if cfg.ControlPlane != nil {
+		for c, conf := range tlsBootstrapCfg.Clusters {
+			conf.Server, err = kubeadmutil.GetLocalAPIEndpoint(&cfg.ControlPlane.LocalAPIEndpoint)
+			if err != nil {
+				return errors.Wrapf(err, "could not get LocalAPIEndpoint")
 			}
+			tlsBootstrapCfg.Clusters[c] = conf
 		}
 	}
 
@@ -252,13 +233,6 @@ func runKubeletStartJoinPhase(c workflow.RunData) (returnErr error) {
 	fmt.Println("[kubelet-start] Starting the kubelet")
 	kubeletphase.TryStartKubelet()
 
-	// Run the same code as KubeletWaitBootstrapPhase would do if the ControlPlaneKubeletLocalMode feature gate is disabled.
-	if !features.Enabled(initCfg.FeatureGates, features.ControlPlaneKubeletLocalMode) {
-		if err := runKubeletWaitBootstrapPhase(c); err != nil {
-			return err
-		}
-	}
-
 	return nil
 }
 

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

@@ -180,10 +180,7 @@ func WriteKubeletConfigFiles(cfg *kubeadmapi.InitConfiguration, kubeletDir strin
 	return nil
 }
 
-// UpdateKubeletKubeconfigServer changes the Server URL in the kubelets kubeconfig if necessary depending on the
-// ControlPlaneKubeletLocalMode feature gate.
-// TODO: remove this function once ControlPlaneKubeletLocalMode goes GA and is hardcoded to be enabled by default:
-// https://github.com/kubernetes/kubeadm/issues/2271
+// UpdateKubeletKubeconfigServer changes the Server URL in the kubelet's kubeconfig if necessary.
 func UpdateKubeletKubeconfigServer(cfg *kubeadmapi.InitConfiguration, dryRun bool) error {
 	kubeletKubeConfigFilePath := filepath.Join(kubeadmconstants.KubernetesDir, kubeadmconstants.KubeletKubeConfigFileName)
 
@@ -216,21 +213,12 @@ func UpdateKubeletKubeconfigServer(cfg *kubeadmapi.InitConfiguration, dryRun boo
 	}
 
 	var targetServer string
-	if features.Enabled(cfg.FeatureGates, features.ControlPlaneKubeletLocalMode) {
-		// Skip changing kubeconfig file if Server does not match the ControlPlaneEndpoint.
-		if config.Clusters[configContext.Cluster].Server != controlPlaneAPIEndpoint || controlPlaneAPIEndpoint == localAPIEndpoint {
-			klog.V(2).Infof("Skipping update of the Server URL in %s, because it's already not equal to %q or already matches the localAPIEndpoint", kubeletKubeConfigFilePath, controlPlaneAPIEndpoint)
-			return nil
-		}
-		targetServer = localAPIEndpoint
-	} else {
-		// Skip changing kubeconfig file if Server does not match the localAPIEndpoint.
-		if config.Clusters[configContext.Cluster].Server != localAPIEndpoint {
-			klog.V(2).Infof("Skipping update of the Server URL in %s, because it already matches the controlPlaneAPIEndpoint", kubeletKubeConfigFilePath)
-			return nil
-		}
-		targetServer = controlPlaneAPIEndpoint
+	// Skip changing kubeconfig file if Server does not match the ControlPlaneEndpoint.
+	if config.Clusters[configContext.Cluster].Server != controlPlaneAPIEndpoint || controlPlaneAPIEndpoint == localAPIEndpoint {
+		klog.V(2).Infof("Skipping update of the Server URL in %s, because it's already not equal to %q or already matches the localAPIEndpoint", kubeletKubeConfigFilePath, controlPlaneAPIEndpoint)
+		return nil
 	}
+	targetServer = localAPIEndpoint
 
 	if dryRun {
 		fmt.Printf("[dryrun] Would change the Server URL from %q to %q in %s and try to restart kubelet\n", config.Clusters[configContext.Cluster].Server, targetServer, kubeletKubeConfigFilePath)