pkg/operator/status: Drop kubelet skew guard

The kubelet skew guard is from 1471d2c (Bug 1986453: Check for API
server and node versions skew, 2021-07-27, #2658).  But the Kube API
server also landed a similar guard in
openshift/cluster-kube-apiserver-operator@9ce4f74775 (add
KubeletVersionSkewController, 2021-08-26,
openshift/cluster-kube-apiserver-operator#1199).
openshift/enhancements@0ba744e750 (eus-upgrades-mvp: don't enforce
skew check in MCO, 2021-04-29, openshift/enhancements#762) had shifted
the proposal from MCO-guards to KAS-guards, so I'm not clear on why
the MCO guard landed.  This commit drops it, to consolidate around the
KAS-side guard.

Author: wking

pkg/operator/status.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"reflect"
 	"sort"
-	"strconv"
 	"strings"
 	"time"
 
@@ -255,13 +254,6 @@ func (optr *Operator) syncDegradedStatus(co *configv1.ClusterOperator, ierr sync
 	cov1helpers.SetStatusCondition(&co.Status.Conditions, coDegradedCondition, clock.RealClock{})
 }
 
-const (
-	skewUnchecked   = "KubeletSkewUnchecked"
-	skewSupported   = "KubeletSkewSupported"
-	skewUnsupported = "KubeletSkewUnsupported"
-	skewPresent     = "KubeletSkewPresent"
-)
-
 // syncUpgradeableStatus applies the new condition to the mco's ClusterOperator object.
 func (optr *Operator) syncUpgradeableStatus(co *configv1.ClusterOperator) error {
 
@@ -289,13 +281,8 @@ func (optr *Operator) syncUpgradeableStatus(co *configv1.ClusterOperator) error
 		coStatusCondition.Reason = "ClusterOnCgroupV1"
 		coStatusCondition.Message = "Cluster is using deprecated cgroup v1 and is not upgradable. Please update the `CgroupMode` in the `nodes.config.openshift.io` object to 'v2'. Once upgraded, the cluster cannot be changed back to cgroup v1"
 	}
-	var updating, degraded, interrupted bool
+	var degraded, interrupted bool
 	for _, pool := range pools {
-		// collect updating status but continue to check each pool to see if any pool is degraded
-		if isPoolStatusConditionTrue(pool, mcfgv1.MachineConfigPoolUpdating) {
-			updating = true
-		}
-
 		interrupted = isPoolStatusConditionTrue(pool, mcfgv1.MachineConfigPoolBuildInterrupted)
 
 		degraded = isPoolStatusConditionTrue(pool, mcfgv1.MachineConfigPoolDegraded)
@@ -315,39 +302,6 @@ func (optr *Operator) syncUpgradeableStatus(co *configv1.ClusterOperator) error
 		}
 	}
 
-	// don't overwrite status if updating or degraded
-	if !updating && !degraded && !interrupted {
-		skewStatus, status, err := optr.isKubeletSkewSupported(pools)
-		if err != nil {
-			klog.Errorf("Error checking version skew: %v, kubelet skew status: %v, status reason: %v, status message: %v", err, skewStatus, status.Reason, status.Message)
-			coStatusCondition.Reason = status.Reason
-			coStatusCondition.Message = status.Message
-			cov1helpers.SetStatusCondition(&co.Status.Conditions, coStatusCondition, clock.RealClock{})
-		}
-		switch skewStatus {
-		case skewUnchecked:
-			coStatusCondition.Reason = status.Reason
-			coStatusCondition.Message = status.Message
-			cov1helpers.SetStatusCondition(&co.Status.Conditions, coStatusCondition, clock.RealClock{})
-		case skewUnsupported:
-			coStatusCondition.Reason = status.Reason
-			coStatusCondition.Message = status.Message
-			mcoObjectRef := &corev1.ObjectReference{
-				Kind:      co.Kind,
-				Name:      co.Name,
-				Namespace: co.Namespace,
-				UID:       co.GetUID(),
-			}
-			klog.Infof("kubelet skew status: %v, status reason: %v", skewStatus, status.Reason)
-			optr.eventRecorder.Eventf(mcoObjectRef, corev1.EventTypeWarning, coStatusCondition.Reason, coStatusCondition.Message)
-			cov1helpers.SetStatusCondition(&co.Status.Conditions, coStatusCondition, clock.RealClock{})
-		case skewPresent:
-			coStatusCondition.Reason = status.Reason
-			coStatusCondition.Message = status.Message
-			klog.Infof("kubelet skew status: %v, status reason: %v", skewStatus, status.Reason)
-			cov1helpers.SetStatusCondition(&co.Status.Conditions, coStatusCondition, clock.RealClock{})
-		}
-	}
 	cov1helpers.SetStatusCondition(&co.Status.Conditions, coStatusCondition, clock.RealClock{})
 	return nil
 }
@@ -519,85 +473,6 @@ func (optr *Operator) cfeEvalCgroupsV1() (bool, error) {
 	return nodeClusterConfig.Spec.CgroupMode == configv1.CgroupModeV1, nil
 }
 
-// isKubeletSkewSupported checks the version skew of kube-apiserver and node kubelet version.
-// Returns the skew status. version skew > 2 is not supported.
-func (optr *Operator) isKubeletSkewSupported(pools []*mcfgv1.MachineConfigPool) (skewStatus string, coStatus configv1.ClusterOperatorStatusCondition, err error) {
-	coStatus = configv1.ClusterOperatorStatusCondition{}
-	kubeAPIServerStatus, err := optr.clusterOperatorLister.Get("kube-apiserver")
-	if err != nil {
-		coStatus.Reason = skewUnchecked
-		coStatus.Message = fmt.Sprintf("An error occurred when checking kubelet version skew: %v", err)
-		return skewUnchecked, coStatus, err
-	}
-	// looks like
-	//   - name: kube-apiserver
-	//     version: 1.21.0-rc.0
-	kubeAPIServerVersion := ""
-	for _, version := range kubeAPIServerStatus.Status.Versions {
-		if version.Name != "kube-apiserver" {
-			continue
-		}
-		kubeAPIServerVersion = version.Version
-		break
-	}
-	if kubeAPIServerVersion == "" {
-		err = fmt.Errorf("kube-apiserver does not yet have a version")
-		coStatus.Reason = skewUnchecked
-		coStatus.Message = fmt.Sprintf("An error occurred when checking kubelet version skew: %v", err.Error())
-		return skewUnchecked, coStatus, err
-	}
-	kubeAPIServerMinorVersion, err := getMinorKubeletVersion(kubeAPIServerVersion)
-	if err != nil {
-		coStatus.Reason = skewUnchecked
-		coStatus.Message = fmt.Sprintf("An error occurred when checking kubelet version skew: %v", err)
-		return skewUnchecked, coStatus, err
-	}
-	var (
-		lastError      error
-		kubeletVersion string
-	)
-	nodes, err := optr.GetAllManagedNodes(pools)
-	if err != nil {
-		err = fmt.Errorf("getting all managed nodes failed: %w", err)
-		coStatus.Reason = skewUnchecked
-		coStatus.Message = fmt.Sprintf("An error occurred when getting all the managed nodes: %v", err.Error())
-	}
-	for _, node := range nodes {
-		// looks like kubeletVersion: v1.21.0-rc.0+6143dea
-		kubeletVersion = node.Status.NodeInfo.KubeletVersion
-		if kubeletVersion == "" {
-			continue
-		}
-		nodeMinorVersion, err := getMinorKubeletVersion(kubeletVersion)
-		if err != nil {
-			lastError = err
-			continue
-		}
-		if nodeMinorVersion+2 < kubeAPIServerMinorVersion {
-			coStatus.Reason = skewUnsupported
-			coStatus.Message = fmt.Sprintf("One or more nodes have an unsupported kubelet version skew. Please see `oc get nodes` for details and upgrade all nodes so that they have a kubelet version of at least %v.", getMinimalSkewSupportNodeVersion(kubeAPIServerVersion))
-			return skewUnsupported, coStatus, nil
-		}
-		if nodeMinorVersion+2 == kubeAPIServerMinorVersion {
-			coStatus.Reason = skewPresent
-			coStatus.Message = fmt.Sprintf("Current kubelet version %v will not be supported by newer kube-apiserver. Please upgrade the kubelet first if plan to upgrade the kube-apiserver", kubeletVersion)
-			return skewPresent, coStatus, nil
-		}
-	}
-	if kubeletVersion == "" {
-		err = fmt.Errorf("kubelet does not yet have a version")
-		coStatus.Reason = skewUnchecked
-		coStatus.Message = fmt.Sprintf("An error occurred when checking kubelet version skew: %v", err.Error())
-		return skewUnchecked, coStatus, err
-	}
-	if lastError != nil {
-		coStatus.Reason = skewUnchecked
-		coStatus.Message = fmt.Sprintf("An error occurred when checking kubelet version skew: %v", err)
-		return skewUnchecked, coStatus, lastError
-	}
-	return skewSupported, coStatus, nil
-}
-
 // GetAllManagedNodes returns the nodes managed by MCO
 func (optr *Operator) GetAllManagedNodes(pools []*mcfgv1.MachineConfigPool) ([]*corev1.Node, error) {
 	nodes := []*corev1.Node{}
@@ -615,40 +490,6 @@ func (optr *Operator) GetAllManagedNodes(pools []*mcfgv1.MachineConfigPool) ([]*
 	return nodes, nil
 }
 
-// getMinorKubeletVersion parses the minor version number of kubelet
-func getMinorKubeletVersion(version string) (int, error) {
-	tokens := strings.Split(version, ".")
-	if len(tokens) < 2 {
-		return 0, fmt.Errorf("incorrect version syntax: %q", version)
-	}
-	minorVersion, err := strconv.ParseInt(tokens[1], 10, 32)
-	if err != nil {
-		return 0, err
-	}
-	return int(minorVersion), nil
-}
-
-// getMinimalSkewSupportNodeVersion returns the minimal supported node kubelet version.
-func getMinimalSkewSupportNodeVersion(version string) string {
-	// drop the pre-release and commit hash
-	idx := strings.Index(version, "-")
-	if idx >= 0 {
-		version = version[:idx]
-	}
-
-	idx = strings.Index(version, "+")
-	if idx >= 0 {
-		version = version[:idx]
-	}
-
-	tokens := strings.Split(version, ".")
-	if minorVersion, err := strconv.ParseInt(tokens[1], 10, 32); err == nil {
-		tokens[1] = strconv.Itoa(int(minorVersion) - 2)
-		return strings.Join(tokens, ".")
-	}
-	return version
-}
-
 func (optr *Operator) fetchClusterOperator() (*configv1.ClusterOperator, error) {
 	co, err := optr.clusterOperatorLister.Get(optr.name)