KCP: remove code handling Kubernetes <= v1.21

Signed-off-by: Stefan Büringer buringerst@vmware.com

controlplane/kubeadm/internal/controllers/controller.go

@@ -802,12 +802,7 @@ func (r *KubeadmControlPlaneReconciler) reconcileEtcdMembers(ctx context.Context
 		return errors.Wrap(err, "cannot get remote client to workload cluster")
 	}
 
-	parsedVersion, err := semver.ParseTolerant(controlPlane.KCP.Spec.Version)
-	if err != nil {
-		return errors.Wrapf(err, "failed to parse kubernetes version %q", controlPlane.KCP.Spec.Version)
-	}
-
-	removedMembers, err := workloadCluster.ReconcileEtcdMembers(ctx, nodeNames, parsedVersion)
+	removedMembers, err := workloadCluster.ReconcileEtcdMembers(ctx, nodeNames)
 	if err != nil {
 		return errors.Wrap(err, "failed attempt to reconcile etcd members")
 	}

controlplane/kubeadm/internal/controllers/fakes_test.go

@@ -84,7 +84,7 @@ func (f *fakeWorkloadCluster) ForwardEtcdLeadership(_ context.Context, _ *cluste
 	return nil
 }
 
-func (f *fakeWorkloadCluster) ReconcileEtcdMembers(_ context.Context, _ []string, _ semver.Version) ([]string, error) {
+func (f *fakeWorkloadCluster) ReconcileEtcdMembers(_ context.Context, _ []string) ([]string, error) {
 	return nil, nil
 }
 
@@ -129,10 +129,6 @@ func (f *fakeWorkloadCluster) RemoveEtcdMemberForMachine(_ context.Context, _ *c
 	return nil
 }
 
-func (f *fakeWorkloadCluster) RemoveMachineFromKubeadmConfigMap(_ context.Context, _ *clusterv1.Machine, _ semver.Version) error {
-	return nil
-}
-
 func (f *fakeWorkloadCluster) EtcdMembers(_ context.Context) ([]string, error) {
 	return f.EtcdMembersResult, nil
 }

controlplane/kubeadm/internal/controllers/remediation.go

@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/blang/semver/v4"
 	"github.com/go-logr/logr"
 	"github.com/pkg/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -227,16 +226,6 @@ func (r *KubeadmControlPlaneReconciler) reconcileUnhealthyMachines(ctx context.C
 
 			// NOTE: etcd member removal will be performed by the kcp-cleanup hook after machine completes drain & all volumes are detached.
 		}
-
-		parsedVersion, err := semver.ParseTolerant(controlPlane.KCP.Spec.Version)
-		if err != nil {
-			return ctrl.Result{}, errors.Wrapf(err, "failed to parse kubernetes version %q", controlPlane.KCP.Spec.Version)
-		}
-
-		if err := workloadCluster.RemoveMachineFromKubeadmConfigMap(ctx, machineToBeRemediated, parsedVersion); err != nil {
-			log.Error(err, "Failed to remove machine from kubeadm ConfigMap")
-			return ctrl.Result{}, err
-		}
 	}
 
 	// Delete the machine

controlplane/kubeadm/internal/controllers/scale.go

@@ -20,7 +20,6 @@ import (
 	"context"
 	"strings"
 
-	"github.com/blang/semver/v4"
 	"github.com/pkg/errors"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
@@ -139,16 +138,6 @@ func (r *KubeadmControlPlaneReconciler) scaleDownControlPlane(
 		// NOTE: etcd member removal will be performed by the kcp-cleanup hook after machine completes drain & all volumes are detached.
 	}
 
-	parsedVersion, err := semver.ParseTolerant(controlPlane.KCP.Spec.Version)
-	if err != nil {
-		return ctrl.Result{}, errors.Wrapf(err, "failed to parse kubernetes version %q", controlPlane.KCP.Spec.Version)
-	}
-
-	if err := workloadCluster.RemoveMachineFromKubeadmConfigMap(ctx, machineToDelete, parsedVersion); err != nil {
-		logger.Error(err, "Failed to remove machine from kubeadm ConfigMap")
-		return ctrl.Result{}, err
-	}
-
 	logger = logger.WithValues("Machine", klog.KObj(machineToDelete))
 	if err := r.Client.Delete(ctx, machineToDelete); err != nil && !apierrors.IsNotFound(err) {
 		logger.Error(err, "Failed to delete control plane machine")

controlplane/kubeadm/internal/workload_cluster.go

@@ -52,7 +52,6 @@ import (
 	"sigs.k8s.io/cluster-api/util/certs"
 	containerutil "sigs.k8s.io/cluster-api/util/container"
 	"sigs.k8s.io/cluster-api/util/patch"
-	"sigs.k8s.io/cluster-api/util/version"
 )
 
 const (
@@ -68,18 +67,6 @@ const (
 )
 
 var (
-	// Starting from v1.22.0 kubeadm dropped the usage of the ClusterStatus entry from the kubeadm-config ConfigMap
-	// so we're not anymore required to remove API endpoints for control plane nodes after deletion.
-	//
-	// NOTE: The following assumes that kubeadm version equals to Kubernetes version.
-	minKubernetesVersionWithoutClusterStatus = semver.MustParse("1.22.0")
-
-	// Starting from v1.21.0 kubeadm defaults to systemdCGroup driver, as well as images built with ImageBuilder,
-	// so it is necessary to mutate the kubelet-config-xx ConfigMap.
-	//
-	// NOTE: The following assumes that kubeadm version equals to Kubernetes version.
-	minVerKubeletSystemdDriver = semver.MustParse("1.21.0")
-
 	// Starting from v1.24.0 kubeadm uses "kubelet-config" a ConfigMap name for KubeletConfiguration,
 	// Dropping the X-Y suffix.
 	//
@@ -124,15 +111,13 @@ type WorkloadCluster interface {
 	UpdateKubeProxyImageInfo(ctx context.Context, kcp *controlplanev1.KubeadmControlPlane, version semver.Version) error
 	UpdateCoreDNS(ctx context.Context, kcp *controlplanev1.KubeadmControlPlane, version semver.Version) error
 	RemoveEtcdMemberForMachine(ctx context.Context, machine *clusterv1.Machine) error
-	RemoveMachineFromKubeadmConfigMap(ctx context.Context, machine *clusterv1.Machine, version semver.Version) error
-	RemoveNodeFromKubeadmConfigMap(ctx context.Context, nodeName string, version semver.Version) error
 	ForwardEtcdLeadership(ctx context.Context, machine *clusterv1.Machine, leaderCandidate *clusterv1.Machine) error
 	AllowBootstrapTokensToGetNodes(ctx context.Context) error
 	AllowClusterAdminPermissions(ctx context.Context, version semver.Version) error
 	UpdateClusterConfiguration(ctx context.Context, version semver.Version, mutators ...func(*bootstrapv1.ClusterConfiguration)) error
 
 	// State recovery tasks.
-	ReconcileEtcdMembers(ctx context.Context, nodeNames []string, version semver.Version) ([]string, error)
+	ReconcileEtcdMembers(ctx context.Context, nodeNames []string) ([]string, error)
 }
 
 // Workload defines operations on workload clusters.
@@ -277,33 +262,31 @@ func (w *Workload) UpdateKubeletConfigMap(ctx context.Context, version semver.Ve
 	// NOTE: It is considered safe to update the kubelet-config-1.21 ConfigMap
 	// because only new nodes using v1.21 images will pick up the change during
 	// kubeadm join.
-	if version.GE(minVerKubeletSystemdDriver) {
-		data, ok := cm.Data[kubeletConfigKey]
-		if !ok {
-			return errors.Errorf("unable to find %q key in %s", kubeletConfigKey, cm.Name)
-		}
-		kubeletConfig, err := yamlToUnstructured([]byte(data))
-		if err != nil {
-			return errors.Wrapf(err, "unable to decode kubelet ConfigMap's %q content to Unstructured object", kubeletConfigKey)
-		}
-		cgroupDriver, _, err := unstructured.NestedString(kubeletConfig.UnstructuredContent(), cgroupDriverKey)
-		if err != nil {
-			return errors.Wrapf(err, "unable to extract %q from Kubelet ConfigMap's %q", cgroupDriverKey, cm.Name)
-		}
+	data, ok := cm.Data[kubeletConfigKey]
+	if !ok {
+		return errors.Errorf("unable to find %q key in %s", kubeletConfigKey, cm.Name)
+	}
+	kubeletConfig, err := yamlToUnstructured([]byte(data))
+	if err != nil {
+		return errors.Wrapf(err, "unable to decode kubelet ConfigMap's %q content to Unstructured object", kubeletConfigKey)
+	}
+	cgroupDriver, _, err := unstructured.NestedString(kubeletConfig.UnstructuredContent(), cgroupDriverKey)
+	if err != nil {
+		return errors.Wrapf(err, "unable to extract %q from Kubelet ConfigMap's %q", cgroupDriverKey, cm.Name)
+	}
 
-		// If the value is not already explicitly set by the user, change according to kubeadm/image builder new requirements.
-		if cgroupDriver == "" {
-			cgroupDriver = "systemd"
+	// If the value is not already explicitly set by the user, change according to kubeadm/image builder new requirements.
+	if cgroupDriver == "" {
+		cgroupDriver = "systemd"
 
-			if err := unstructured.SetNestedField(kubeletConfig.UnstructuredContent(), cgroupDriver, cgroupDriverKey); err != nil {
-				return errors.Wrapf(err, "unable to update %q on Kubelet ConfigMap's %q", cgroupDriverKey, cm.Name)
-			}
-			updated, err := yaml.Marshal(kubeletConfig)
-			if err != nil {
-				return errors.Wrapf(err, "unable to encode Kubelet ConfigMap's %q to YAML", cm.Name)
-			}
-			cm.Data[kubeletConfigKey] = string(updated)
+		if err := unstructured.SetNestedField(kubeletConfig.UnstructuredContent(), cgroupDriver, cgroupDriverKey); err != nil {
+			return errors.Wrapf(err, "unable to update %q on Kubelet ConfigMap's %q", cgroupDriverKey, cm.Name)
 		}
+		updated, err := yaml.Marshal(kubeletConfig)
+		if err != nil {
+			return errors.Wrapf(err, "unable to encode Kubelet ConfigMap's %q to YAML", cm.Name)
+		}
+		cm.Data[kubeletConfigKey] = string(updated)
 	}
 
 	// Update the name to the new name
@@ -338,27 +321,6 @@ func (w *Workload) UpdateSchedulerInKubeadmConfigMap(scheduler bootstrapv1.Contr
 	}
 }
 
-// RemoveMachineFromKubeadmConfigMap removes the entry for the machine from the kubeadm configmap.
-func (w *Workload) RemoveMachineFromKubeadmConfigMap(ctx context.Context, machine *clusterv1.Machine, version semver.Version) error {
-	if machine == nil || machine.Status.NodeRef == nil {
-		// Nothing to do, no node for Machine
-		return nil
-	}
-
-	return w.RemoveNodeFromKubeadmConfigMap(ctx, machine.Status.NodeRef.Name, version)
-}
-
-// RemoveNodeFromKubeadmConfigMap removes the entry for the node from the kubeadm configmap.
-func (w *Workload) RemoveNodeFromKubeadmConfigMap(ctx context.Context, name string, v semver.Version) error {
-	if version.Compare(v, minKubernetesVersionWithoutClusterStatus, version.WithoutPreReleases()) >= 0 {
-		return nil
-	}
-
-	return w.updateClusterStatus(ctx, func(s *bootstrapv1.ClusterStatus) {
-		delete(s.APIEndpoints, name)
-	}, v)
-}
-
 // updateClusterStatus gets the ClusterStatus kubeadm-config ConfigMap, converts it to the
 // Cluster API representation, and then applies a mutation func; if changes are detected, the
 // data are converted back into the Kubeadm API version in use for the target Kubernetes version and the

controlplane/kubeadm/internal/workload_cluster_etcd.go

@@ -19,7 +19,6 @@ package internal
 import (
 	"context"
 
-	"github.com/blang/semver/v4"
 	"github.com/pkg/errors"
 	kerrors "k8s.io/apimachinery/pkg/util/errors"
 
@@ -36,19 +35,19 @@ type etcdClientFor interface {
 
 // ReconcileEtcdMembers iterates over all etcd members and finds members that do not have corresponding nodes.
 // If there are any such members, it deletes them from etcd and removes their nodes from the kubeadm configmap so that kubeadm does not run etcd health checks on them.
-func (w *Workload) ReconcileEtcdMembers(ctx context.Context, nodeNames []string, version semver.Version) ([]string, error) {
+func (w *Workload) ReconcileEtcdMembers(ctx context.Context, nodeNames []string) ([]string, error) {
 	allRemovedMembers := []string{}
 	allErrs := []error{}
 	for _, nodeName := range nodeNames {
-		removedMembers, errs := w.reconcileEtcdMember(ctx, nodeNames, nodeName, version)
+		removedMembers, errs := w.reconcileEtcdMember(ctx, nodeNames, nodeName)
 		allRemovedMembers = append(allRemovedMembers, removedMembers...)
 		allErrs = append(allErrs, errs...)
 	}
 
 	return allRemovedMembers, kerrors.NewAggregate(allErrs)
 }
 
-func (w *Workload) reconcileEtcdMember(ctx context.Context, nodeNames []string, nodeName string, version semver.Version) ([]string, []error) {
+func (w *Workload) reconcileEtcdMember(ctx context.Context, nodeNames []string, nodeName string) ([]string, []error) {
 	// Create the etcd Client for the etcd Pod scheduled on the Node
 	etcdClient, err := w.etcdClientGenerator.forFirstAvailableNode(ctx, []string{nodeName})
 	if err != nil {
@@ -84,10 +83,6 @@ loopmembers:
 		if err := w.removeMemberForNode(ctx, member.Name); err != nil {
 			errs = append(errs, err)
 		}
-
-		if err := w.RemoveNodeFromKubeadmConfigMap(ctx, member.Name, version); err != nil {
-			errs = append(errs, err)
-		}
 	}
 	return removedMembers, errs
 }