目录

 

开启kubectl命令进行taint操作

对taints操作的检查

运行

执行具体污点操作

返回更新后的污点集

添加污点

删除污点

附：能否调度DaemonSet到节点的代码

---

开启kubectl命令进行taint操作

func NewCmdTaint(f cmdutil.Factory, streams genericclioptions.IOStreams) *cobra.Command {
	options := &TaintOptions{
		PrintFlags: genericclioptions.NewPrintFlags("tainted").WithTypeSetter(scheme.Scheme),
		IOStreams:  streams,
	}

	validArgs := []string{"node"}

	cmd := &cobra.Command{
		Use: "taint NODE NAME KEY_1=VAL_1:TAINT_EFFECT_1 ... KEY_N=VAL_N:TAINT_EFFECT_N",
		DisableFlagsInUseLine: true,
		Short:   i18n.T("Update the taints on one or more nodes"),
		Long:    fmt.Sprintf(taintLong, validation.DNS1123SubdomainMaxLength, validation.LabelValueMaxLength),
		Example: taintExample,
		Run: func(cmd *cobra.Command, args []string) {
			if err := options.Complete(f, cmd, args); err != nil {
				cmdutil.CheckErr(err)
			}
			if err := options.Validate(); err != nil {
				cmdutil.CheckErr(cmdutil.UsageErrorf(cmd, err.Error()))
			}
			if err := options.RunTaint(); err != nil {
				cmdutil.CheckErr(err)
			}
		},
		ValidArgs: validArgs,
	}

	options.PrintFlags.AddFlags(cmd)

	cmdutil.AddValidateFlags(cmd)
	cmd.Flags().StringVarP(&options.selector, "selector", "l", options.selector, "Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")
	cmd.Flags().BoolVar(&options.overwrite, "overwrite", options.overwrite, "If true, allow taints to be overwritten, otherwise reject taint updates that overwrite existing taints.")
	cmd.Flags().BoolVar(&options.all, "all", options.all, "Select all nodes in the cluster")
	return cmd
}

命令以IOStreams的形式传入。

对taints操作的检查

// Validate checks to the TaintOptions to see if there is sufficient information run the command.
func (o TaintOptions) Validate() error {
	resourceType := strings.ToLower(o.resources[0])
	validResources, isValidResource := []string{"node", "nodes"}, false
	for _, validResource := range validResources {
		if resourceType == validResource {
			isValidResource = true
			break
		}
	}
	if !isValidResource {
		return fmt.Errorf("invalid resource type %s, only %q are supported", o.resources[0], validResources)
	}

	// check the format of taint args and checks removed taints aren't in the new taints list
	var conflictTaints []string
	for _, taintAdd := range o.taintsToAdd {
		for _, taintRemove := range o.taintsToRemove {
			if taintAdd.Key != taintRemove.Key {
				continue
			}
			if len(taintRemove.Effect) == 0 || taintAdd.Effect == taintRemove.Effect {
				conflictTaint := fmt.Sprintf("{\"%s\":\"%s\"}", taintRemove.Key, taintRemove.Effect)
				conflictTaints = append(conflictTaints, conflictTaint)
			}
		}
	}
	if len(conflictTaints) > 0 {
		return fmt.Errorf("can not both modify and remove the following taint(s) in the same command: %s", strings.Join(conflictTaints, ", "))
	}
	return o.validateFlags()
}

运行

// RunTaint does the work
func (o TaintOptions) RunTaint() error {
	r := o.builder.Do()
	if err := r.Err(); err != nil {
		return err
	}

	return r.Visit(func(info *resource.Info, err error) error {
		if err != nil {
			return err
		}

		obj := info.Object
		name, namespace := info.Name, info.Namespace
		oldData, err := json.Marshal(obj)
		if err != nil {
			return err
		}
		operation, err := o.updateTaints(obj)
		if err != nil {
			return err
		}
		newData, err := json.Marshal(obj)
		if err != nil {
			return err
		}
		patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldData, newData, obj)
		createdPatch := err == nil
		if err != nil {
			glog.V(2).Infof("couldn't compute patch: %v", err)
		}

		mapping := info.ResourceMapping()
		client, err := o.ClientForMapping(mapping)
		if err != nil {
			return err
		}
		helper := resource.NewHelper(client, mapping)

		var outputObj runtime.Object
		if createdPatch {
			outputObj, err = helper.Patch(namespace, name, types.StrategicMergePatchType, patchBytes, nil)
		} else {
			outputObj, err = helper.Replace(namespace, name, false, obj)
		}
		if err != nil {
			return err
		}
		outputObj = cmdutil.AsDefaultVersionedOrOriginal(outputObj, mapping)

		printer, err := o.ToPrinter(operation)
		if err != nil {
			return err
		}
		return printer.PrintObj(outputObj, o.Out)
	})
}

执行具体污点操作

运行操作的方法中实际调用了updateTaints方法来

// updateTaints applies a taint option(o) to a node in cluster after computing the net effect of operation(i.e. does it result in an overwrite?), it reports back the end result in a way that user can easily interpret.
func (o TaintOptions) updateTaints(obj runtime.Object) (string, error) {
	node, ok := obj.(*v1.Node)
	if !ok {
		return "", fmt.Errorf("unexpected type %T, expected Node", obj)
	}
	if !o.overwrite {
		if exists := taintutils.CheckIfTaintsAlreadyExists(node.Spec.Taints, o.taintsToAdd); len(exists) != 0 {
			return "", fmt.Errorf("Node %s already has %v taint(s) with same effect(s) and --overwrite is false", node.Name, exists)
		}
	}
	operation, newTaints, err := taintutils.ReorganizeTaints(node, o.overwrite, o.taintsToAdd, o.taintsToRemove)
	if err != nil {
		return "", err
	}
	node.Spec.Taints = newTaints
	return operation, nil
}

返回更新后的污点集

ReorganizeTaints方法用于返回更新后的污点集

// ReorganizeTaints returns the updated set of taints, taking into account old taints that were not updated,
// old taints that were updated, old taints that were deleted, and new taints.
func ReorganizeTaints(node *v1.Node, overwrite bool, taintsToAdd []v1.Taint, taintsToRemove []v1.Taint) (string, []v1.Taint, error) {
	newTaints := append([]v1.Taint{}, taintsToAdd...)
	oldTaints := node.Spec.Taints
	// add taints that already existing but not updated to newTaints
	added := addTaints(oldTaints, &newTaints)
	allErrs, deleted := deleteTaints(taintsToRemove, &newTaints)
	if (added && deleted) || overwrite {
		return MODIFIED, newTaints, utilerrors.NewAggregate(allErrs)
	} else if added {
		return TAINTED, newTaints, utilerrors.NewAggregate(allErrs)
	}
	return UNTAINTED, newTaints, utilerrors.NewAggregate(allErrs)
}

添加污点

// addTaints adds the newTaints list to existing ones and updates the newTaints List.
// TODO: This needs a rewrite to take only the new values instead of appended newTaints list to be consistent.
func addTaints(oldTaints []v1.Taint, newTaints *[]v1.Taint) bool {
	for _, oldTaint := range oldTaints {
		existsInNew := false
		for _, taint := range *newTaints {
			if taint.MatchTaint(&oldTaint) {
				existsInNew = true
				break
			}
		}
		if !existsInNew {
			*newTaints = append(*newTaints, oldTaint)
		}
	}
	return len(oldTaints) != len(*newTaints)
}

删除污点

// deleteTaints deletes the given taints from the node's taintlist.
func deleteTaints(taintsToRemove []v1.Taint, newTaints *[]v1.Taint) ([]error, bool) {
	allErrs := []error{}
	var removed bool
	for _, taintToRemove := range taintsToRemove {
		removed = false
		if len(taintToRemove.Effect) > 0 {
			*newTaints, removed = DeleteTaint(*newTaints, &taintToRemove)
		} else {
			*newTaints, removed = DeleteTaintsByKey(*newTaints, taintToRemove.Key)
		}
		if !removed {
			allErrs = append(allErrs, fmt.Errorf("taint %q not found", taintToRemove.ToString()))
		}
	}
	return allErrs, removed
}

附：能否调度DaemonSet到节点的代码

func schedulableNodes(c clientset.Interface, ds *apps.DaemonSet) []string {
	nodeList, err := c.CoreV1().Nodes().List(metav1.ListOptions{})
	framework.ExpectNoError(err)
	nodeNames := make([]string, 0)
	for _, node := range nodeList.Items {
		if !canScheduleOnNode(node, ds) {
			framework.Logf("DaemonSet pods can't tolerate node %s with taints %+v, skip checking this node", node.Name, node.Spec.Taints)
			continue
		}
		nodeNames = append(nodeNames, node.Name)
	}
	return nodeNames
}