func AddOrUpdateTaint(node *v1.Node, taint *v1.Taint) (*v1.Node, bool, error) {
	newNode := node.DeepCopy()
	nodeTaints := newNode.Spec.Taints
	var newTaints []v1.Taint
	updated := false
	for i := range nodeTaints {
		if taint.MatchTaint(&nodeTaints[i]) {
			if helper.Semantic.DeepEqual(*taint, nodeTaints[i]) {
				return newNode, false, nil
			}
			newTaints = append(newTaints, *taint)
			updated = true
			continue
		}
		newTaints = append(newTaints, nodeTaints[i])
	}
	if !updated {
		newTaints = append(newTaints, *taint)
	}
	newNode.Spec.Taints = newTaints
	return newNode, true, nil
}
AddOrUpdateTaint tries to add a taint to annotations list. Returns a new copy of updated Node and true if something was updated
false otherwise.
package taints
import (
	"fmt"
	"strings"
	"k8s.io/api/core/v1"
	utilerrors "k8s.io/apimachinery/pkg/util/errors"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/apimachinery/pkg/util/validation"
	api "k8s.io/kubernetes/pkg/apis/core"
	"k8s.io/kubernetes/pkg/apis/core/helper"
)
const (
	MODIFIED  = "modified"
	TAINTED   = "tainted"
	UNTAINTED = "untainted"
)
func parseTaint(st string) (v1.Taint, error) {
	var taint v1.Taint
	parts := strings.Split(st, "=")
	if len(parts) != 2 || len(parts[1]) == 0 || len(validation.IsQualifiedName(parts[0])) > 0 {
		return taint, fmt.Errorf("invalid taint spec: %v", st)
	}
	parts2 := strings.Split(parts[1], ":")
	errs := validation.IsValidLabelValue(parts2[0])
	if len(parts2) != 2 || len(errs) != 0 {
		return taint, fmt.Errorf("invalid taint spec: %v, %s", st, strings.Join(errs, "; "))
	}
	effect := v1.TaintEffect(parts2[1])
	if err := validateTaintEffect(effect); err != nil {
		return taint, err
	}
	taint.Key = parts[0]
	taint.Value = parts2[0]
	taint.Effect = effect
	return taint, nil
}
func validateTaintEffect(effect v1.TaintEffect) error {
	if effect != v1.TaintEffectNoSchedule && effect != v1.TaintEffectPreferNoSchedule && effect != v1.TaintEffectNoExecute {
		return fmt.Errorf("invalid taint effect: %v, unsupported taint effect", effect)
	}
	return nil
}
func NewTaintsVar(ptr *[]api.Taint) taintsVar {
	return taintsVar{
		ptr: ptr,
	}
}
type taintsVar struct {
	ptr *[]api.Taint
}
func (t taintsVar) Set(s string) error {
	if len(s) == 0 {
		*t.ptr = nil
		return nil
	}
	sts := strings.Split(s, ",")
	var taints []api.Taint
	for _, st := range sts {
		taint, err := parseTaint(st)
		if err != nil {
			return err
		}
		taints = append(taints, api.Taint{Key: taint.Key, Value: taint.Value, Effect: api.TaintEffect(taint.Effect)})
	}
	*t.ptr = taints
	return nil
}
func (t taintsVar) String() string {
	if len(*t.ptr) == 0 {
		return ""
	}
	var taints []string
	for _, taint := range *t.ptr {
		taints = append(taints, fmt.Sprintf("%s=%s:%s", taint.Key, taint.Value, taint.Effect))
	}
	return strings.Join(taints, ",")
}
func (t taintsVar) Type() string {
	return "[]api.Taint"
}
func ParseTaints(spec []string) ([]v1.Taint, []v1.Taint, error) {
	var taints, taintsToRemove []v1.Taint
	uniqueTaints := map[v1.TaintEffect]sets.String{}
	for _, taintSpec := range spec {
		if strings.Index(taintSpec, "=") != -1 && strings.Index(taintSpec, ":") != -1 {
			newTaint, err := parseTaint(taintSpec)
			if err != nil {
				return nil, nil, err
			}
			if len(uniqueTaints[newTaint.Effect]) > 0 && uniqueTaints[newTaint.Effect].Has(newTaint.Key) {
				return nil, nil, fmt.Errorf("duplicated taints with the same key and effect: %v", newTaint)
			}
			if len(uniqueTaints[newTaint.Effect]) == 0 {
				uniqueTaints[newTaint.Effect] = sets.String{}
			}
			uniqueTaints[newTaint.Effect].Insert(newTaint.Key)
			taints = append(taints, newTaint)
		} else if strings.HasSuffix(taintSpec, "-") {
			taintKey := taintSpec[:len(taintSpec)-1]
			var effect v1.TaintEffect
			if strings.Index(taintKey, ":") != -1 {
				parts := strings.Split(taintKey, ":")
				taintKey = parts[0]
				effect = v1.TaintEffect(parts[1])
			}
			if len(effect) > 0 {
				err := validateTaintEffect(effect)
				if err != nil {
					return nil, nil, err
				}
			}
			taintsToRemove = append(taintsToRemove, v1.Taint{Key: taintKey, Effect: effect})
		} else {
			return nil, nil, fmt.Errorf("unknown taint spec: %v", taintSpec)
		}
	}
	return taints, taintsToRemove, nil
}
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
	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)
}
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
}
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)
}
func CheckIfTaintsAlreadyExists(oldTaints []v1.Taint, taints []v1.Taint) string {
	var existingTaintList = make([]string, 0)
	for _, taint := range taints {
		for _, oldTaint := range oldTaints {
			if taint.Key == oldTaint.Key && taint.Effect == oldTaint.Effect {
				existingTaintList = append(existingTaintList, taint.Key)
			}
		}
	}
	return strings.Join(existingTaintList, ",")
}
func DeleteTaintsByKey(taints []v1.Taint, taintKey string) ([]v1.Taint, bool) {
	newTaints := []v1.Taint{}
	deleted := false
	for i := range taints {
		if taintKey == taints[i].Key {
			deleted = true
			continue
		}
		newTaints = append(newTaints, taints[i])
	}
	return newTaints, deleted
}
func DeleteTaint(taints []v1.Taint, taintToDelete *v1.Taint) ([]v1.Taint, bool) {
	newTaints := []v1.Taint{}
	deleted := false
	for i := range taints {
		if taintToDelete.MatchTaint(&taints[i]) {
			deleted = true
			continue
		}
		newTaints = append(newTaints, taints[i])
	}
	return newTaints, deleted
}
func RemoveTaint(node *v1.Node, taint *v1.Taint) (*v1.Node, bool, error) {
	newNode := node.DeepCopy()
	nodeTaints := newNode.Spec.Taints
	if len(nodeTaints) == 0 {
		return newNode, false, nil
	}
	if !TaintExists(nodeTaints, taint) {
		return newNode, false, nil
	}
	newTaints, _ := DeleteTaint(nodeTaints, taint)
	newNode.Spec.Taints = newTaints
	return newNode, true, nil
}