validation.go

/*
Copyright 2014 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package validation

import (
	"encoding/json"
	"fmt"
	"math"
	"net"
	"path"
	"path/filepath"
	"reflect"
	"regexp"
	"strings"

	"github.com/golang/glog"

	"k8s.io/api/core/v1"
	apiequality "k8s.io/apimachinery/pkg/api/equality"
	"k8s.io/apimachinery/pkg/api/resource"
	apimachineryvalidation "k8s.io/apimachinery/pkg/api/validation"
	genericvalidation "k8s.io/apimachinery/pkg/api/validation"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	unversionedvalidation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/util/diff"
	"k8s.io/apimachinery/pkg/util/intstr"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/apimachinery/pkg/util/validation"
	"k8s.io/apimachinery/pkg/util/validation/field"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/helper"
	apiservice "k8s.io/kubernetes/pkg/api/service"
	k8s_api_v1 "k8s.io/kubernetes/pkg/api/v1"
	v1helper "k8s.io/kubernetes/pkg/api/v1/helper"
	"k8s.io/kubernetes/pkg/capabilities"
	"k8s.io/kubernetes/pkg/features"
	"k8s.io/kubernetes/pkg/security/apparmor"
)

// TODO: delete this global variable when we enable the validation of common
// fields by default.
var RepairMalformedUpdates bool = genericvalidation.RepairMalformedUpdates

const isNegativeErrorMsg string = apimachineryvalidation.IsNegativeErrorMsg
const isInvalidQuotaResource string = `must be a standard resource for quota`
const fieldImmutableErrorMsg string = genericvalidation.FieldImmutableErrorMsg
const isNotIntegerErrorMsg string = `must be an integer`

var pdPartitionErrorMsg string = validation.InclusiveRangeError(1, 255)
var volumeModeErrorMsg string = "must be a number between 0 and 0777 (octal), both inclusive"

// BannedOwners is a black list of object that are not allowed to be owners.
var BannedOwners = genericvalidation.BannedOwners

var iscsiInitiatorIqnRegex = regexp.MustCompile(`iqn\.\d{4}-\d{2}\.([[:alnum:]-.]+)(:[^,;*&$|\s]+)$`)
var iscsiInitiatorEuiRegex = regexp.MustCompile(`^eui.[[:alnum:]]{16}$`)
var iscsiInitiatorNaaRegex = regexp.MustCompile(`^naa.[[:alnum:]]{32}$`)

// ValidateHasLabel requires that metav1.ObjectMeta has a Label with key and expectedValue
func ValidateHasLabel(meta metav1.ObjectMeta, fldPath *field.Path, key, expectedValue string) field.ErrorList {
	allErrs := field.ErrorList{}
	actualValue, found := meta.Labels[key]
	if !found {
		allErrs = append(allErrs, field.Required(fldPath.Child("labels").Key(key),
			fmt.Sprintf("must be '%s'", expectedValue)))
		return allErrs
	}
	if actualValue != expectedValue {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("labels").Key(key), meta.Labels,
			fmt.Sprintf("must be '%s'", expectedValue)))
	}
	return allErrs
}

// ValidateAnnotations validates that a set of annotations are correctly defined.
func ValidateAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	return genericvalidation.ValidateAnnotations(annotations, fldPath)
}

func ValidateDNS1123Label(value string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for _, msg := range validation.IsDNS1123Label(value) {
		allErrs = append(allErrs, field.Invalid(fldPath, value, msg))
	}
	return allErrs
}

// ValidateDNS1123Subdomain validates that a name is a proper DNS subdomain.
func ValidateDNS1123Subdomain(value string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for _, msg := range validation.IsDNS1123Subdomain(value) {
		allErrs = append(allErrs, field.Invalid(fldPath, value, msg))
	}
	return allErrs
}

func ValidatePodSpecificAnnotations(annotations map[string]string, spec *api.PodSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if value, isMirror := annotations[api.MirrorPodAnnotationKey]; isMirror {
		if len(spec.NodeName) == 0 {
			allErrs = append(allErrs, field.Invalid(fldPath.Key(api.MirrorPodAnnotationKey), value, "must set spec.nodeName if mirror pod annotation is set"))
		}
	}

	if annotations[api.TolerationsAnnotationKey] != "" {
		allErrs = append(allErrs, ValidateTolerationsInPodAnnotations(annotations, fldPath)...)
	}

	allErrs = append(allErrs, ValidateSeccompPodAnnotations(annotations, fldPath)...)
	allErrs = append(allErrs, ValidateAppArmorPodAnnotations(annotations, spec, fldPath)...)

	sysctls, err := helper.SysctlsFromPodAnnotation(annotations[api.SysctlsPodAnnotationKey])
	if err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Key(api.SysctlsPodAnnotationKey), annotations[api.SysctlsPodAnnotationKey], err.Error()))
	} else {
		allErrs = append(allErrs, validateSysctls(sysctls, fldPath.Key(api.SysctlsPodAnnotationKey))...)
	}
	unsafeSysctls, err := helper.SysctlsFromPodAnnotation(annotations[api.UnsafeSysctlsPodAnnotationKey])
	if err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Key(api.UnsafeSysctlsPodAnnotationKey), annotations[api.UnsafeSysctlsPodAnnotationKey], err.Error()))
	} else {
		allErrs = append(allErrs, validateSysctls(unsafeSysctls, fldPath.Key(api.UnsafeSysctlsPodAnnotationKey))...)
	}
	inBoth := sysctlIntersection(sysctls, unsafeSysctls)
	if len(inBoth) > 0 {
		allErrs = append(allErrs, field.Invalid(fldPath.Key(api.UnsafeSysctlsPodAnnotationKey), strings.Join(inBoth, ", "), "can not be safe and unsafe"))
	}

	return allErrs
}

// ValidateTolerationsInPodAnnotations tests that the serialized tolerations in Pod.Annotations has valid data
func ValidateTolerationsInPodAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	tolerations, err := helper.GetTolerationsFromPodAnnotations(annotations)
	if err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath, api.TolerationsAnnotationKey, err.Error()))
		return allErrs
	}

	if len(tolerations) > 0 {
		allErrs = append(allErrs, ValidateTolerations(tolerations, fldPath.Child(api.TolerationsAnnotationKey))...)
	}

	return allErrs
}

func ValidatePodSpecificAnnotationUpdates(newPod, oldPod *api.Pod, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	newAnnotations := newPod.Annotations
	oldAnnotations := oldPod.Annotations
	for k, oldVal := range oldAnnotations {
		if newVal, exists := newAnnotations[k]; exists && newVal == oldVal {
			continue // No change.
		}
		if strings.HasPrefix(k, apparmor.ContainerAnnotationKeyPrefix) {
			allErrs = append(allErrs, field.Forbidden(fldPath.Key(k), "may not remove or update AppArmor annotations"))
		}
		if k == api.MirrorPodAnnotationKey {
			allErrs = append(allErrs, field.Forbidden(fldPath.Key(k), "may not remove or update mirror pod annotation"))
		}
	}
	// Check for additions
	for k := range newAnnotations {
		if _, ok := oldAnnotations[k]; ok {
			continue // No change.
		}
		if strings.HasPrefix(k, apparmor.ContainerAnnotationKeyPrefix) {
			allErrs = append(allErrs, field.Forbidden(fldPath.Key(k), "may not add AppArmor annotations"))
		}
		if k == api.MirrorPodAnnotationKey {
			allErrs = append(allErrs, field.Forbidden(fldPath.Key(k), "may not add mirror pod annotation"))
		}
	}
	allErrs = append(allErrs, ValidatePodSpecificAnnotations(newAnnotations, &newPod.Spec, fldPath)...)
	return allErrs
}

func ValidateEndpointsSpecificAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	return allErrs
}

func ValidateOwnerReferences(ownerReferences []metav1.OwnerReference, fldPath *field.Path) field.ErrorList {
	return genericvalidation.ValidateOwnerReferences(ownerReferences, fldPath)
}

// ValidateNameFunc validates that the provided name is valid for a given resource type.
// Not all resources have the same validation rules for names. Prefix is true
// if the name will have a value appended to it.  If the name is not valid,
// this returns a list of descriptions of individual characteristics of the
// value that were not valid.  Otherwise this returns an empty list or nil.
type ValidateNameFunc apimachineryvalidation.ValidateNameFunc

// maskTrailingDash replaces the final character of a string with a subdomain safe
// value if is a dash.
func maskTrailingDash(name string) string {
	if strings.HasSuffix(name, "-") {
		return name[:len(name)-2] + "a"
	}
	return name
}

// ValidatePodName can be used to check whether the given pod name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidatePodName = NameIsDNSSubdomain

// ValidateReplicationControllerName can be used to check whether the given replication
// controller name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateReplicationControllerName = NameIsDNSSubdomain

// ValidateServiceName can be used to check whether the given service name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateServiceName = NameIsDNS1035Label

// ValidateNodeName can be used to check whether the given node name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateNodeName = NameIsDNSSubdomain

// ValidateNamespaceName can be used to check whether the given namespace name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateNamespaceName = apimachineryvalidation.ValidateNamespaceName

// ValidateLimitRangeName can be used to check whether the given limit range name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateLimitRangeName = NameIsDNSSubdomain

// ValidateResourceQuotaName can be used to check whether the given
// resource quota name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateResourceQuotaName = NameIsDNSSubdomain

// ValidateSecretName can be used to check whether the given secret name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateSecretName = NameIsDNSSubdomain

// ValidateServiceAccountName can be used to check whether the given service account name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateServiceAccountName = apimachineryvalidation.ValidateServiceAccountName

// ValidateEndpointsName can be used to check whether the given endpoints name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateEndpointsName = NameIsDNSSubdomain

// ValidateClusterName can be used to check whether the given cluster name is valid.
var ValidateClusterName = genericvalidation.ValidateClusterName

// ValidateClassName can be used to check whether the given class name is valid.
// It is defined here to avoid import cycle between pkg/apis/storage/validation
// (where it should be) and this file.
var ValidateClassName = NameIsDNSSubdomain

// ValidatePiorityClassName can be used to check whether the given priority
// class name is valid.
var ValidatePriorityClassName = NameIsDNSSubdomain

// TODO update all references to these functions to point to the genericvalidation ones
// NameIsDNSSubdomain is a ValidateNameFunc for names that must be a DNS subdomain.
func NameIsDNSSubdomain(name string, prefix bool) []string {
	return apimachineryvalidation.NameIsDNSSubdomain(name, prefix)
}

// NameIsDNSLabel is a ValidateNameFunc for names that must be a DNS 1123 label.
func NameIsDNSLabel(name string, prefix bool) []string {
	return apimachineryvalidation.NameIsDNSLabel(name, prefix)
}

// NameIsDNS1035Label is a ValidateNameFunc for names that must be a DNS 952 label.
func NameIsDNS1035Label(name string, prefix bool) []string {
	return apimachineryvalidation.NameIsDNS1035Label(name, prefix)
}

// Validates that given value is not negative.
func ValidateNonnegativeField(value int64, fldPath *field.Path) field.ErrorList {
	return apimachineryvalidation.ValidateNonnegativeField(value, fldPath)
}

// Validates that a Quantity is not negative
func ValidateNonnegativeQuantity(value resource.Quantity, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if value.Cmp(resource.Quantity{}) < 0 {
		allErrs = append(allErrs, field.Invalid(fldPath, value.String(), isNegativeErrorMsg))
	}
	return allErrs
}

func ValidateImmutableField(newVal, oldVal interface{}, fldPath *field.Path) field.ErrorList {
	return genericvalidation.ValidateImmutableField(newVal, oldVal, fldPath)
}

func ValidateImmutableAnnotation(newVal string, oldVal string, annotation string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if oldVal != newVal {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("annotations", annotation), newVal, fieldImmutableErrorMsg))
	}
	return allErrs
}

// ValidateObjectMeta validates an object's metadata on creation. It expects that name generation has already
// been performed.
// It doesn't return an error for rootscoped resources with namespace, because namespace should already be cleared before.
// TODO: Remove calls to this method scattered in validations of specific resources, e.g., ValidatePodUpdate.
func ValidateObjectMeta(meta *metav1.ObjectMeta, requiresNamespace bool, nameFn ValidateNameFunc, fldPath *field.Path) field.ErrorList {
	allErrs := genericvalidation.ValidateObjectMeta(meta, requiresNamespace, apimachineryvalidation.ValidateNameFunc(nameFn), fldPath)
	// run additional checks for the finalizer name
	for i := range meta.Finalizers {
		allErrs = append(allErrs, validateKubeFinalizerName(string(meta.Finalizers[i]), fldPath.Child("finalizers").Index(i))...)
	}
	return allErrs
}

// ValidateObjectMetaUpdate validates an object's metadata when updated
func ValidateObjectMetaUpdate(newMeta, oldMeta *metav1.ObjectMeta, fldPath *field.Path) field.ErrorList {
	allErrs := genericvalidation.ValidateObjectMetaUpdate(newMeta, oldMeta, fldPath)
	// run additional checks for the finalizer name
	for i := range newMeta.Finalizers {
		allErrs = append(allErrs, validateKubeFinalizerName(string(newMeta.Finalizers[i]), fldPath.Child("finalizers").Index(i))...)
	}

	return allErrs
}

func ValidateNoNewFinalizers(newFinalizers []string, oldFinalizers []string, fldPath *field.Path) field.ErrorList {
	return genericvalidation.ValidateNoNewFinalizers(newFinalizers, oldFinalizers, fldPath)
}

func ValidateVolumes(volumes []api.Volume, fldPath *field.Path) (sets.String, field.ErrorList) {
	allErrs := field.ErrorList{}

	allNames := sets.String{}
	for i, vol := range volumes {
		idxPath := fldPath.Index(i)
		namePath := idxPath.Child("name")
		el := validateVolumeSource(&vol.VolumeSource, idxPath, vol.Name)
		if len(vol.Name) == 0 {
			el = append(el, field.Required(namePath, ""))
		} else {
			el = append(el, ValidateDNS1123Label(vol.Name, namePath)...)
		}
		if allNames.Has(vol.Name) {
			el = append(el, field.Duplicate(namePath, vol.Name))
		}
		if len(el) == 0 {
			allNames.Insert(vol.Name)
		} else {
			allErrs = append(allErrs, el...)
		}

	}
	return allNames, allErrs
}

func validateVolumeSource(source *api.VolumeSource, fldPath *field.Path, volName string) field.ErrorList {
	numVolumes := 0
	allErrs := field.ErrorList{}
	if source.EmptyDir != nil {
		numVolumes++
		if !utilfeature.DefaultFeatureGate.Enabled(features.LocalStorageCapacityIsolation) {
			if source.EmptyDir.SizeLimit != nil && source.EmptyDir.SizeLimit.Cmp(resource.Quantity{}) != 0 {
				allErrs = append(allErrs, field.Forbidden(fldPath.Child("emptyDir").Child("sizeLimit"), "SizeLimit field disabled by feature-gate for EmptyDir volumes"))
			}
		} else {
			if source.EmptyDir.SizeLimit != nil && source.EmptyDir.SizeLimit.Cmp(resource.Quantity{}) < 0 {
				allErrs = append(allErrs, field.Forbidden(fldPath.Child("emptyDir").Child("sizeLimit"), "SizeLimit field must be a valid resource quantity"))
			}
		}
		if !utilfeature.DefaultFeatureGate.Enabled(features.HugePages) && source.EmptyDir.Medium == api.StorageMediumHugePages {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("emptyDir").Child("medium"), "HugePages medium is disabled by feature-gate for EmptyDir volumes"))
		}
	}
	if source.HostPath != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("hostPath"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateHostPathVolumeSource(source.HostPath, fldPath.Child("hostPath"))...)
		}
	}
	if source.GitRepo != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("gitRepo"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateGitRepoVolumeSource(source.GitRepo, fldPath.Child("gitRepo"))...)
		}
	}
	if source.GCEPersistentDisk != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("gcePersistentDisk"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateGCEPersistentDiskVolumeSource(source.GCEPersistentDisk, fldPath.Child("persistentDisk"))...)
		}
	}
	if source.AWSElasticBlockStore != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("awsElasticBlockStore"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateAWSElasticBlockStoreVolumeSource(source.AWSElasticBlockStore, fldPath.Child("awsElasticBlockStore"))...)
		}
	}
	if source.Secret != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("secret"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateSecretVolumeSource(source.Secret, fldPath.Child("secret"))...)
		}
	}
	if source.NFS != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("nfs"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateNFSVolumeSource(source.NFS, fldPath.Child("nfs"))...)
		}
	}
	if source.ISCSI != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("iscsi"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateISCSIVolumeSource(source.ISCSI, fldPath.Child("iscsi"))...)
		}
		if source.ISCSI.InitiatorName != nil && len(volName+":"+source.ISCSI.TargetPortal) > 64 {
			tooLongErr := "Total length of <volume name>:<iscsi.targetPortal> must be under 64 characters if iscsi.initiatorName is specified."
			allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), volName, tooLongErr))
		}
	}
	if source.Glusterfs != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("glusterfs"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateGlusterfsVolumeSource(source.Glusterfs, fldPath.Child("glusterfs"))...)
		}
	}
	if source.Flocker != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("flocker"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateFlockerVolumeSource(source.Flocker, fldPath.Child("flocker"))...)
		}
	}
	if source.PersistentVolumeClaim != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("persistentVolumeClaim"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validatePersistentClaimVolumeSource(source.PersistentVolumeClaim, fldPath.Child("persistentVolumeClaim"))...)
		}
	}
	if source.RBD != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("rbd"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateRBDVolumeSource(source.RBD, fldPath.Child("rbd"))...)
		}
	}
	if source.Cinder != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("cinder"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateCinderVolumeSource(source.Cinder, fldPath.Child("cinder"))...)
		}
	}
	if source.CephFS != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("cephFS"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateCephFSVolumeSource(source.CephFS, fldPath.Child("cephfs"))...)
		}
	}
	if source.Quobyte != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("quobyte"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateQuobyteVolumeSource(source.Quobyte, fldPath.Child("quobyte"))...)
		}
	}
	if source.DownwardAPI != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("downwarAPI"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateDownwardAPIVolumeSource(source.DownwardAPI, fldPath.Child("downwardAPI"))...)
		}
	}
	if source.FC != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("fc"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateFCVolumeSource(source.FC, fldPath.Child("fc"))...)
		}
	}
	if source.FlexVolume != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("flexVolume"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateFlexVolumeSource(source.FlexVolume, fldPath.Child("flexVolume"))...)
		}
	}
	if source.ConfigMap != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("configMap"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateConfigMapVolumeSource(source.ConfigMap, fldPath.Child("configMap"))...)
		}
	}

	if source.AzureFile != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("azureFile"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateAzureFile(source.AzureFile, fldPath.Child("azureFile"))...)
		}
	}

	if source.VsphereVolume != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("vsphereVolume"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateVsphereVolumeSource(source.VsphereVolume, fldPath.Child("vsphereVolume"))...)
		}
	}
	if source.PhotonPersistentDisk != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("photonPersistentDisk"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validatePhotonPersistentDiskVolumeSource(source.PhotonPersistentDisk, fldPath.Child("photonPersistentDisk"))...)
		}
	}
	if source.PortworxVolume != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("portworxVolume"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validatePortworxVolumeSource(source.PortworxVolume, fldPath.Child("portworxVolume"))...)
		}
	}
	if source.AzureDisk != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("azureDisk"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateAzureDisk(source.AzureDisk, fldPath.Child("azureDisk"))...)
		}
	}
	if source.StorageOS != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("storageos"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateStorageOSVolumeSource(source.StorageOS, fldPath.Child("storageos"))...)
		}
	}
	if source.Projected != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("projected"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateProjectedVolumeSource(source.Projected, fldPath.Child("projected"))...)
		}
	}
	if source.ScaleIO != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("scaleIO"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateScaleIOVolumeSource(source.ScaleIO, fldPath.Child("scaleIO"))...)
		}
	}

	if numVolumes == 0 {
		allErrs = append(allErrs, field.Required(fldPath, "must specify a volume type"))
	}

	return allErrs
}

func validateHostPathVolumeSource(hostPath *api.HostPathVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(hostPath.Path) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
		return allErrs
	}

	allErrs = append(allErrs, validatePathNoBacksteps(hostPath.Path, fldPath.Child("path"))...)
	allErrs = append(allErrs, validateHostPathType(hostPath.Type, fldPath.Child("type"))...)
	return allErrs
}

func validateGitRepoVolumeSource(gitRepo *api.GitRepoVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(gitRepo.Repository) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("repository"), ""))
	}

	pathErrs := validateLocalDescendingPath(gitRepo.Directory, fldPath.Child("directory"))
	allErrs = append(allErrs, pathErrs...)
	return allErrs
}

func validateISCSIVolumeSource(iscsi *api.ISCSIVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(iscsi.TargetPortal) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("targetPortal"), ""))
	}
	if len(iscsi.IQN) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("iqn"), ""))
	} else {
		if !strings.HasPrefix(iscsi.IQN, "iqn") && !strings.HasPrefix(iscsi.IQN, "eui") && !strings.HasPrefix(iscsi.IQN, "naa") {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("iqn"), iscsi.IQN, "must be valid format"))
		} else if strings.HasPrefix(iscsi.IQN, "iqn") && !iscsiInitiatorIqnRegex.MatchString(iscsi.IQN) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("iqn"), iscsi.IQN, "must be valid format"))
		} else if strings.HasPrefix(iscsi.IQN, "eui") && !iscsiInitiatorEuiRegex.MatchString(iscsi.IQN) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("iqn"), iscsi.IQN, "must be valid format"))
		} else if strings.HasPrefix(iscsi.IQN, "naa") && !iscsiInitiatorNaaRegex.MatchString(iscsi.IQN) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("iqn"), iscsi.IQN, "must be valid format"))
		}
	}
	if iscsi.Lun < 0 || iscsi.Lun > 255 {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("lun"), iscsi.Lun, validation.InclusiveRangeError(0, 255)))
	}
	if (iscsi.DiscoveryCHAPAuth || iscsi.SessionCHAPAuth) && iscsi.SecretRef == nil {
		allErrs = append(allErrs, field.Required(fldPath.Child("secretRef"), ""))
	}
	if iscsi.InitiatorName != nil {
		initiator := *iscsi.InitiatorName
		if !strings.HasPrefix(initiator, "iqn") && !strings.HasPrefix(initiator, "eui") && !strings.HasPrefix(initiator, "naa") {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("initiatorname"), initiator, "must be valid format"))
		}
		if strings.HasPrefix(initiator, "iqn") && !iscsiInitiatorIqnRegex.MatchString(initiator) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("initiatorname"), initiator, "must be valid format"))
		} else if strings.HasPrefix(initiator, "eui") && !iscsiInitiatorEuiRegex.MatchString(initiator) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("initiatorname"), initiator, "must be valid format"))
		} else if strings.HasPrefix(initiator, "naa") && !iscsiInitiatorNaaRegex.MatchString(initiator) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("initiatorname"), initiator, "must be valid format"))
		}
	}
	return allErrs
}

func validateFCVolumeSource(fc *api.FCVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(fc.TargetWWNs) < 1 && len(fc.WWIDs) < 1 {
		allErrs = append(allErrs, field.Required(fldPath.Child("targetWWNs"), "must specify either targetWWNs or wwids, but not both"))
	}

	if len(fc.TargetWWNs) != 0 && len(fc.WWIDs) != 0 {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("targetWWNs"), fc.TargetWWNs, "targetWWNs and wwids can not be specified simultaneously"))
	}

	if len(fc.TargetWWNs) != 0 {
		if fc.Lun == nil {
			allErrs = append(allErrs, field.Required(fldPath.Child("lun"), "lun is required if targetWWNs is specified"))
		} else {
			if *fc.Lun < 0 || *fc.Lun > 255 {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("lun"), fc.Lun, validation.InclusiveRangeError(0, 255)))
			}
		}
	}
	return allErrs
}

func validateGCEPersistentDiskVolumeSource(pd *api.GCEPersistentDiskVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(pd.PDName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("pdName"), ""))
	}
	if pd.Partition < 0 || pd.Partition > 255 {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("partition"), pd.Partition, pdPartitionErrorMsg))
	}
	return allErrs
}

func validateAWSElasticBlockStoreVolumeSource(PD *api.AWSElasticBlockStoreVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(PD.VolumeID) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeID"), ""))
	}
	if PD.Partition < 0 || PD.Partition > 255 {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("partition"), PD.Partition, pdPartitionErrorMsg))
	}
	return allErrs
}

func validateSecretVolumeSource(secretSource *api.SecretVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(secretSource.SecretName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("secretName"), ""))
	}

	secretMode := secretSource.DefaultMode
	if secretMode != nil && (*secretMode > 0777 || *secretMode < 0) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("defaultMode"), *secretMode, volumeModeErrorMsg))
	}

	itemsPath := fldPath.Child("items")
	for i, kp := range secretSource.Items {
		itemPath := itemsPath.Index(i)
		allErrs = append(allErrs, validateKeyToPath(&kp, itemPath)...)
	}
	return allErrs
}

func validateConfigMapVolumeSource(configMapSource *api.ConfigMapVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(configMapSource.Name) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
	}

	configMapMode := configMapSource.DefaultMode
	if configMapMode != nil && (*configMapMode > 0777 || *configMapMode < 0) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("defaultMode"), *configMapMode, volumeModeErrorMsg))
	}

	itemsPath := fldPath.Child("items")
	for i, kp := range configMapSource.Items {
		itemPath := itemsPath.Index(i)
		allErrs = append(allErrs, validateKeyToPath(&kp, itemPath)...)
	}
	return allErrs
}

func validateKeyToPath(kp *api.KeyToPath, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(kp.Key) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("key"), ""))
	}
	if len(kp.Path) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
	}
	allErrs = append(allErrs, validateLocalNonReservedPath(kp.Path, fldPath.Child("path"))...)
	if kp.Mode != nil && (*kp.Mode > 0777 || *kp.Mode < 0) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("mode"), *kp.Mode, volumeModeErrorMsg))
	}

	return allErrs
}

func validatePersistentClaimVolumeSource(claim *api.PersistentVolumeClaimVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(claim.ClaimName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("claimName"), ""))
	}
	return allErrs
}

func validateNFSVolumeSource(nfs *api.NFSVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(nfs.Server) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("server"), ""))
	}
	if len(nfs.Path) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
	}
	if !path.IsAbs(nfs.Path) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("path"), nfs.Path, "must be an absolute path"))
	}
	return allErrs
}

func validateQuobyteVolumeSource(quobyte *api.QuobyteVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(quobyte.Registry) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("registry"), "must be a host:port pair or multiple pairs separated by commas"))
	} else {
		for _, hostPortPair := range strings.Split(quobyte.Registry, ",") {
			if _, _, err := net.SplitHostPort(hostPortPair); err != nil {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("registry"), quobyte.Registry, "must be a host:port pair or multiple pairs separated by commas"))
			}
		}
	}

	if len(quobyte.Volume) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volume"), ""))
	}
	return allErrs
}

func validateGlusterfsVolumeSource(glusterfs *api.GlusterfsVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(glusterfs.EndpointsName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("endpoints"), ""))
	}
	if len(glusterfs.Path) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
	}
	return allErrs
}

func validateFlockerVolumeSource(flocker *api.FlockerVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(flocker.DatasetName) == 0 && len(flocker.DatasetUUID) == 0 {
		//TODO: consider adding a RequiredOneOf() error for this and similar cases
		allErrs = append(allErrs, field.Required(fldPath, "one of datasetName and datasetUUID is required"))
	}
	if len(flocker.DatasetName) != 0 && len(flocker.DatasetUUID) != 0 {
		allErrs = append(allErrs, field.Invalid(fldPath, "resource", "datasetName and datasetUUID can not be specified simultaneously"))
	}
	if strings.Contains(flocker.DatasetName, "/") {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("datasetName"), flocker.DatasetName, "must not contain '/'"))
	}
	return allErrs
}

var validDownwardAPIFieldPathExpressions = sets.NewString(
	"metadata.name",
	"metadata.namespace",
	"metadata.labels",
	"metadata.annotations",
	"metadata.uid")

func validateDownwardAPIVolumeFile(file *api.DownwardAPIVolumeFile, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if len(file.Path) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
	}
	allErrs = append(allErrs, validateLocalNonReservedPath(file.Path, fldPath.Child("path"))...)
	if file.FieldRef != nil {
		allErrs = append(allErrs, validateObjectFieldSelector(file.FieldRef, &validDownwardAPIFieldPathExpressions, fldPath.Child("fieldRef"))...)
		if file.ResourceFieldRef != nil {
			allErrs = append(allErrs, field.Invalid(fldPath, "resource", "fieldRef and resourceFieldRef can not be specified simultaneously"))
		}
	} else if file.ResourceFieldRef != nil {
		allErrs = append(allErrs, validateContainerResourceFieldSelector(file.ResourceFieldRef, &validContainerResourceFieldPathExpressions, fldPath.Child("resourceFieldRef"), true)...)
	} else {
		allErrs = append(allErrs, field.Required(fldPath, "one of fieldRef and resourceFieldRef is required"))
	}
	if file.Mode != nil && (*file.Mode > 0777 || *file.Mode < 0) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("mode"), *file.Mode, volumeModeErrorMsg))
	}

	return allErrs
}

func validateDownwardAPIVolumeSource(downwardAPIVolume *api.DownwardAPIVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	downwardAPIMode := downwardAPIVolume.DefaultMode
	if downwardAPIMode != nil && (*downwardAPIMode > 0777 || *downwardAPIMode < 0) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("defaultMode"), *downwardAPIMode, volumeModeErrorMsg))
	}

	for _, file := range downwardAPIVolume.Items {
		allErrs = append(allErrs, validateDownwardAPIVolumeFile(&file, fldPath)...)
	}
	return allErrs
}

func validateProjectionSources(projection *api.ProjectedVolumeSource, projectionMode *int32, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	allPaths := sets.String{}

	for _, source := range projection.Sources {
		numSources := 0
		if source.Secret != nil {
			if numSources > 0 {
				allErrs = append(allErrs, field.Forbidden(fldPath.Child("secret"), "may not specify more than 1 volume type"))
			} else {
				numSources++
				if len(source.Secret.Name) == 0 {
					allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
				}
				itemsPath := fldPath.Child("items")
				for i, kp := range source.Secret.Items {
					itemPath := itemsPath.Index(i)
					allErrs = append(allErrs, validateKeyToPath(&kp, itemPath)...)
					if len(kp.Path) > 0 {
						curPath := kp.Path
						if !allPaths.Has(curPath) {
							allPaths.Insert(curPath)
						} else {
							allErrs = append(allErrs, field.Invalid(fldPath, source.Secret.Name, "conflicting duplicate paths"))
						}
					}
				}
			}
		}
		if source.ConfigMap != nil {
			if numSources > 0 {
				allErrs = append(allErrs, field.Forbidden(fldPath.Child("configMap"), "may not specify more than 1 volume type"))
			} else {
				numSources++
				if len(source.ConfigMap.Name) == 0 {
					allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
				}
				itemsPath := fldPath.Child("items")
				for i, kp := range source.ConfigMap.Items {
					itemPath := itemsPath.Index(i)
					allErrs = append(allErrs, validateKeyToPath(&kp, itemPath)...)
					if len(kp.Path) > 0 {
						curPath := kp.Path
						if !allPaths.Has(curPath) {
							allPaths.Insert(curPath)
						} else {
							allErrs = append(allErrs, field.Invalid(fldPath, source.ConfigMap.Name, "conflicting duplicate paths"))
						}

					}
				}
			}
		}
		if source.DownwardAPI != nil {
			if numSources > 0 {
				allErrs = append(allErrs, field.Forbidden(fldPath.Child("downwardAPI"), "may not specify more than 1 volume type"))
			} else {
				numSources++
				for _, file := range source.DownwardAPI.Items {
					allErrs = append(allErrs, validateDownwardAPIVolumeFile(&file, fldPath.Child("downwardAPI"))...)
					if len(file.Path) > 0 {
						curPath := file.Path
						if !allPaths.Has(curPath) {
							allPaths.Insert(curPath)
						} else {
							allErrs = append(allErrs, field.Invalid(fldPath, curPath, "conflicting duplicate paths"))
						}

					}
				}
			}
		}
	}
	return allErrs
}

func validateProjectedVolumeSource(projection *api.ProjectedVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	projectionMode := projection.DefaultMode
	if projectionMode != nil && (*projectionMode > 0777 || *projectionMode < 0) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("defaultMode"), *projectionMode, volumeModeErrorMsg))
	}

	allErrs = append(allErrs, validateProjectionSources(projection, projectionMode, fldPath)...)
	return allErrs
}

var supportedHostPathTypes = sets.NewString(
	string(api.HostPathUnset),
	string(api.HostPathDirectoryOrCreate),
	string(api.HostPathDirectory),
	string(api.HostPathFileOrCreate),
	string(api.HostPathFile),
	string(api.HostPathSocket),
	string(api.HostPathCharDev),
	string(api.HostPathBlockDev))

func validateHostPathType(hostPathType *api.HostPathType, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if hostPathType != nil && !supportedHostPathTypes.Has(string(*hostPathType)) {
		allErrs = append(allErrs, field.NotSupported(fldPath, hostPathType, supportedHostPathTypes.List()))
	}

	return allErrs
}

// This validate will make sure targetPath:
// 1. is not abs path
// 2. does not have any element which is ".."
func validateLocalDescendingPath(targetPath string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if path.IsAbs(targetPath) {
		allErrs = append(allErrs, field.Invalid(fldPath, targetPath, "must be a relative path"))
	}

	allErrs = append(allErrs, validatePathNoBacksteps(targetPath, fldPath)...)

	return allErrs
}

// validatePathNoBacksteps makes sure the targetPath does not have any `..` path elements when split
//
// This assumes the OS of the apiserver and the nodes are the same. The same check should be done
// on the node to ensure there are no backsteps.
func validatePathNoBacksteps(targetPath string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	parts := strings.Split(filepath.ToSlash(targetPath), "/")
	for _, item := range parts {
		if item == ".." {
			allErrs = append(allErrs, field.Invalid(fldPath, targetPath, "must not contain '..'"))
			break // even for `../../..`, one error is sufficient to make the point
		}
	}
	return allErrs
}

// validateMountPropagation verifies that MountPropagation field is valid and
// allowed for given container.
func validateMountPropagation(mountPropagation *api.MountPropagationMode, container *api.Container, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if mountPropagation == nil {
		return allErrs
	}
	if !utilfeature.DefaultFeatureGate.Enabled(features.MountPropagation) {
		allErrs = append(allErrs, field.Forbidden(fldPath, "mount propagation is disabled by feature-gate"))
		return allErrs
	}

	supportedMountPropagations := sets.NewString(string(api.MountPropagationBidirectional), string(api.MountPropagationHostToContainer))
	if !supportedMountPropagations.Has(string(*mountPropagation)) {
		allErrs = append(allErrs, field.NotSupported(fldPath, *mountPropagation, supportedMountPropagations.List()))
	}

	if container == nil {
		// The container is not available yet, e.g. during validation of
		// PodPreset. Stop validation now, Pod validation will refuse final
		// Pods with Bidirectional propagation in non-privileged containers.
		return allErrs
	}

	privileged := container.SecurityContext != nil && container.SecurityContext.Privileged != nil && *container.SecurityContext.Privileged
	if *mountPropagation == api.MountPropagationBidirectional && !privileged {
		allErrs = append(allErrs, field.Forbidden(fldPath, "Bidirectional mount propagation is available only to privileged containers"))
	}
	return allErrs
}

// This validate will make sure targetPath:
// 1. is not abs path
// 2. does not contain any '..' elements
// 3. does not start with '..'
func validateLocalNonReservedPath(targetPath string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, validateLocalDescendingPath(targetPath, fldPath)...)
	// Don't report this error if the check for .. elements already caught it.
	if strings.HasPrefix(targetPath, "..") && !strings.HasPrefix(targetPath, "../") {
		allErrs = append(allErrs, field.Invalid(fldPath, targetPath, "must not start with '..'"))
	}
	return allErrs
}

func validateRBDVolumeSource(rbd *api.RBDVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(rbd.CephMonitors) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("monitors"), ""))
	}
	if len(rbd.RBDImage) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("image"), ""))
	}
	return allErrs
}

func validateCinderVolumeSource(cd *api.CinderVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(cd.VolumeID) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeID"), ""))
	}
	return allErrs
}

func validateCephFSVolumeSource(cephfs *api.CephFSVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(cephfs.Monitors) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("monitors"), ""))
	}
	return allErrs
}

func validateCephFSPersistentVolumeSource(cephfs *api.CephFSPersistentVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(cephfs.Monitors) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("monitors"), ""))
	}
	return allErrs
}

func validateFlexVolumeSource(fv *api.FlexVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(fv.Driver) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("driver"), ""))
	}

	// Make sure user-specified options don't use kubernetes namespaces
	for k := range fv.Options {
		namespace := k
		if parts := strings.SplitN(k, "/", 2); len(parts) == 2 {
			namespace = parts[0]
		}
		normalized := "." + strings.ToLower(namespace)
		if strings.HasSuffix(normalized, ".kubernetes.io") || strings.HasSuffix(normalized, ".k8s.io") {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("options").Key(k), k, "kubernetes.io and k8s.io namespaces are reserved"))
		}
	}

	return allErrs
}

func validateAzureFile(azure *api.AzureFileVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if azure.SecretName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("secretName"), ""))
	}
	if azure.ShareName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("shareName"), ""))
	}
	return allErrs
}

func validateAzureFilePV(azure *api.AzureFilePersistentVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if azure.SecretName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("secretName"), ""))
	}
	if azure.ShareName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("shareName"), ""))
	}
	if azure.SecretNamespace != nil {
		if len(*azure.SecretNamespace) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Child("secretNamespace"), ""))
		}
	}
	return allErrs
}

func validateAzureDisk(azure *api.AzureDiskVolumeSource, fldPath *field.Path) field.ErrorList {
	var supportedCachingModes = sets.NewString(string(api.AzureDataDiskCachingNone), string(api.AzureDataDiskCachingReadOnly), string(api.AzureDataDiskCachingReadWrite))
	var supportedDiskKinds = sets.NewString(string(api.AzureSharedBlobDisk), string(api.AzureDedicatedBlobDisk), string(api.AzureManagedDisk))

	diskUriSupportedManaged := []string{"/subscriptions/{sub-id}/resourcegroups/{group-name}/providers/microsoft.compute/disks/{disk-id}"}
	diskUriSupportedblob := []string{"https://{account-name}.blob.core.windows.net/{container-name}/{disk-name}.vhd"}

	allErrs := field.ErrorList{}
	if azure.DiskName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("diskName"), ""))
	}

	if azure.DataDiskURI == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("diskURI"), ""))
	}

	if azure.CachingMode != nil && !supportedCachingModes.Has(string(*azure.CachingMode)) {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("cachingMode"), *azure.CachingMode, supportedCachingModes.List()))
	}

	if azure.Kind != nil && !supportedDiskKinds.Has(string(*azure.Kind)) {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("kind"), *azure.Kind, supportedDiskKinds.List()))
	}

	// validate that DiskUri is the correct format
	if azure.Kind != nil && *azure.Kind == api.AzureManagedDisk && strings.Index(azure.DataDiskURI, "/subscriptions/") != 0 {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("diskURI"), azure.DataDiskURI, diskUriSupportedManaged))
	}

	if azure.Kind != nil && *azure.Kind != api.AzureManagedDisk && strings.Index(azure.DataDiskURI, "https://") != 0 {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("diskURI"), azure.DataDiskURI, diskUriSupportedblob))
	}

	return allErrs
}

func validateVsphereVolumeSource(cd *api.VsphereVirtualDiskVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(cd.VolumePath) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumePath"), ""))
	}
	return allErrs
}

func validatePhotonPersistentDiskVolumeSource(cd *api.PhotonPersistentDiskVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(cd.PdID) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("pdID"), ""))
	}
	return allErrs
}

func validatePortworxVolumeSource(pwx *api.PortworxVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(pwx.VolumeID) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeID"), ""))
	}
	return allErrs
}

func validateScaleIOVolumeSource(sio *api.ScaleIOVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if sio.Gateway == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("gateway"), ""))
	}
	if sio.System == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("system"), ""))
	}
	if sio.VolumeName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeName"), ""))
	}
	return allErrs
}

func validateScaleIOPersistentVolumeSource(sio *api.ScaleIOPersistentVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if sio.Gateway == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("gateway"), ""))
	}
	if sio.System == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("system"), ""))
	}
	if sio.VolumeName == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeName"), ""))
	}
	return allErrs
}

func validateLocalVolumeSource(ls *api.LocalVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if ls.Path == "" {
		allErrs = append(allErrs, field.Required(fldPath.Child("path"), ""))
		return allErrs
	}

	allErrs = append(allErrs, validatePathNoBacksteps(ls.Path, fldPath.Child("path"))...)
	return allErrs
}

func validateStorageOSVolumeSource(storageos *api.StorageOSVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(storageos.VolumeName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeName"), ""))
	} else {
		allErrs = append(allErrs, ValidateDNS1123Label(storageos.VolumeName, fldPath.Child("volumeName"))...)
	}
	if len(storageos.VolumeNamespace) > 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(storageos.VolumeNamespace, fldPath.Child("volumeNamespace"))...)
	}
	if storageos.SecretRef != nil {
		if len(storageos.SecretRef.Name) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Child("secretRef", "name"), ""))
		}
	}
	return allErrs
}

func validateStorageOSPersistentVolumeSource(storageos *api.StorageOSPersistentVolumeSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(storageos.VolumeName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("volumeName"), ""))
	} else {
		allErrs = append(allErrs, ValidateDNS1123Label(storageos.VolumeName, fldPath.Child("volumeName"))...)
	}
	if len(storageos.VolumeNamespace) > 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(storageos.VolumeNamespace, fldPath.Child("volumeNamespace"))...)
	}
	if storageos.SecretRef != nil {
		if len(storageos.SecretRef.Name) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Child("secretRef", "name"), ""))
		}
		if len(storageos.SecretRef.Namespace) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Child("secretRef", "namespace"), ""))
		}
	}
	return allErrs
}

// ValidatePersistentVolumeName checks that a name is appropriate for a
// PersistentVolumeName object.
var ValidatePersistentVolumeName = NameIsDNSSubdomain

var supportedAccessModes = sets.NewString(string(api.ReadWriteOnce), string(api.ReadOnlyMany), string(api.ReadWriteMany))

var supportedReclaimPolicy = sets.NewString(string(api.PersistentVolumeReclaimDelete), string(api.PersistentVolumeReclaimRecycle), string(api.PersistentVolumeReclaimRetain))

func ValidatePersistentVolume(pv *api.PersistentVolume) field.ErrorList {
	metaPath := field.NewPath("metadata")
	allErrs := ValidateObjectMeta(&pv.ObjectMeta, false, ValidatePersistentVolumeName, metaPath)

	specPath := field.NewPath("spec")
	if len(pv.Spec.AccessModes) == 0 {
		allErrs = append(allErrs, field.Required(specPath.Child("accessModes"), ""))
	}
	for _, mode := range pv.Spec.AccessModes {
		if !supportedAccessModes.Has(string(mode)) {
			allErrs = append(allErrs, field.NotSupported(specPath.Child("accessModes"), mode, supportedAccessModes.List()))
		}
	}

	if len(pv.Spec.Capacity) == 0 {
		allErrs = append(allErrs, field.Required(specPath.Child("capacity"), ""))
	}

	if _, ok := pv.Spec.Capacity[api.ResourceStorage]; !ok || len(pv.Spec.Capacity) > 1 {
		allErrs = append(allErrs, field.NotSupported(specPath.Child("capacity"), pv.Spec.Capacity, []string{string(api.ResourceStorage)}))
	}
	capPath := specPath.Child("capacity")
	for r, qty := range pv.Spec.Capacity {
		allErrs = append(allErrs, validateBasicResource(qty, capPath.Key(string(r)))...)
	}
	if len(string(pv.Spec.PersistentVolumeReclaimPolicy)) > 0 {
		if !supportedReclaimPolicy.Has(string(pv.Spec.PersistentVolumeReclaimPolicy)) {
			allErrs = append(allErrs, field.NotSupported(specPath.Child("persistentVolumeReclaimPolicy"), pv.Spec.PersistentVolumeReclaimPolicy, supportedReclaimPolicy.List()))
		}
	}

	nodeAffinitySpecified, errs := validateStorageNodeAffinityAnnotation(pv.ObjectMeta.Annotations, metaPath.Child("annotations"))
	allErrs = append(allErrs, errs...)

	numVolumes := 0
	if pv.Spec.HostPath != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("hostPath"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateHostPathVolumeSource(pv.Spec.HostPath, specPath.Child("hostPath"))...)
		}
	}
	if pv.Spec.GCEPersistentDisk != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("gcePersistentDisk"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateGCEPersistentDiskVolumeSource(pv.Spec.GCEPersistentDisk, specPath.Child("persistentDisk"))...)
		}
	}
	if pv.Spec.AWSElasticBlockStore != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("awsElasticBlockStore"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateAWSElasticBlockStoreVolumeSource(pv.Spec.AWSElasticBlockStore, specPath.Child("awsElasticBlockStore"))...)
		}
	}
	if pv.Spec.Glusterfs != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("glusterfs"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateGlusterfsVolumeSource(pv.Spec.Glusterfs, specPath.Child("glusterfs"))...)
		}
	}
	if pv.Spec.Flocker != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("flocker"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateFlockerVolumeSource(pv.Spec.Flocker, specPath.Child("flocker"))...)
		}
	}
	if pv.Spec.NFS != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("nfs"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateNFSVolumeSource(pv.Spec.NFS, specPath.Child("nfs"))...)
		}
	}
	if pv.Spec.RBD != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("rbd"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateRBDVolumeSource(pv.Spec.RBD, specPath.Child("rbd"))...)
		}
	}
	if pv.Spec.Quobyte != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("quobyte"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateQuobyteVolumeSource(pv.Spec.Quobyte, specPath.Child("quobyte"))...)
		}
	}
	if pv.Spec.CephFS != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("cephFS"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateCephFSPersistentVolumeSource(pv.Spec.CephFS, specPath.Child("cephfs"))...)
		}
	}
	if pv.Spec.ISCSI != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("iscsi"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateISCSIVolumeSource(pv.Spec.ISCSI, specPath.Child("iscsi"))...)
		}
		if pv.Spec.ISCSI.InitiatorName != nil && len(pv.ObjectMeta.Name+":"+pv.Spec.ISCSI.TargetPortal) > 64 {
			tooLongErr := "Total length of <volume name>:<iscsi.targetPortal> must be under 64 characters if iscsi.initiatorName is specified."
			allErrs = append(allErrs, field.Invalid(metaPath.Child("name"), pv.ObjectMeta.Name, tooLongErr))
		}
	}
	if pv.Spec.Cinder != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("cinder"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateCinderVolumeSource(pv.Spec.Cinder, specPath.Child("cinder"))...)
		}
	}
	if pv.Spec.FC != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("fc"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateFCVolumeSource(pv.Spec.FC, specPath.Child("fc"))...)
		}
	}
	if pv.Spec.FlexVolume != nil {
		numVolumes++
		allErrs = append(allErrs, validateFlexVolumeSource(pv.Spec.FlexVolume, specPath.Child("flexVolume"))...)
	}
	if pv.Spec.AzureFile != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("azureFile"), "may not specify more than 1 volume type"))

		} else {
			numVolumes++
			allErrs = append(allErrs, validateAzureFilePV(pv.Spec.AzureFile, specPath.Child("azureFile"))...)
		}
	}

	if pv.Spec.VsphereVolume != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("vsphereVolume"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateVsphereVolumeSource(pv.Spec.VsphereVolume, specPath.Child("vsphereVolume"))...)
		}
	}
	if pv.Spec.PhotonPersistentDisk != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("photonPersistentDisk"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validatePhotonPersistentDiskVolumeSource(pv.Spec.PhotonPersistentDisk, specPath.Child("photonPersistentDisk"))...)
		}
	}
	if pv.Spec.PortworxVolume != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("portworxVolume"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validatePortworxVolumeSource(pv.Spec.PortworxVolume, specPath.Child("portworxVolume"))...)
		}
	}
	if pv.Spec.AzureDisk != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("azureDisk"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateAzureDisk(pv.Spec.AzureDisk, specPath.Child("azureDisk"))...)
		}
	}
	if pv.Spec.ScaleIO != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("scaleIO"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateScaleIOPersistentVolumeSource(pv.Spec.ScaleIO, specPath.Child("scaleIO"))...)
		}
	}
	if pv.Spec.Local != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("local"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			if !utilfeature.DefaultFeatureGate.Enabled(features.PersistentLocalVolumes) {
				allErrs = append(allErrs, field.Forbidden(specPath.Child("local"), "Local volumes are disabled by feature-gate"))
			}
			allErrs = append(allErrs, validateLocalVolumeSource(pv.Spec.Local, specPath.Child("local"))...)

			// NodeAffinity is required
			if !nodeAffinitySpecified {
				allErrs = append(allErrs, field.Required(metaPath.Child("annotations"), "Local volume requires node affinity"))
			}
		}
	}
	if pv.Spec.StorageOS != nil {
		if numVolumes > 0 {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("storageos"), "may not specify more than 1 volume type"))
		} else {
			numVolumes++
			allErrs = append(allErrs, validateStorageOSPersistentVolumeSource(pv.Spec.StorageOS, specPath.Child("storageos"))...)
		}
	}

	if numVolumes == 0 {
		allErrs = append(allErrs, field.Required(specPath, "must specify a volume type"))
	}

	// do not allow hostPath mounts of '/' to have a 'recycle' reclaim policy
	if pv.Spec.HostPath != nil && path.Clean(pv.Spec.HostPath.Path) == "/" && pv.Spec.PersistentVolumeReclaimPolicy == api.PersistentVolumeReclaimRecycle {
		allErrs = append(allErrs, field.Forbidden(specPath.Child("persistentVolumeReclaimPolicy"), "may not be 'recycle' for a hostPath mount of '/'"))
	}

	if len(pv.Spec.StorageClassName) > 0 {
		for _, msg := range ValidateClassName(pv.Spec.StorageClassName, false) {
			allErrs = append(allErrs, field.Invalid(specPath.Child("storageClassName"), pv.Spec.StorageClassName, msg))
		}
	}

	return allErrs
}

// ValidatePersistentVolumeUpdate tests to see if the update is legal for an end user to make.
// newPv is updated with fields that cannot be changed.
func ValidatePersistentVolumeUpdate(newPv, oldPv *api.PersistentVolume) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = ValidatePersistentVolume(newPv)
	newPv.Status = oldPv.Status
	return allErrs
}

// ValidatePersistentVolumeStatusUpdate tests to see if the status update is legal for an end user to make.
// newPv is updated with fields that cannot be changed.
func ValidatePersistentVolumeStatusUpdate(newPv, oldPv *api.PersistentVolume) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newPv.ObjectMeta, &oldPv.ObjectMeta, field.NewPath("metadata"))
	if len(newPv.ResourceVersion) == 0 {
		allErrs = append(allErrs, field.Required(field.NewPath("resourceVersion"), ""))
	}
	newPv.Spec = oldPv.Spec
	return allErrs
}

// ValidatePersistentVolumeClaim validates a PersistentVolumeClaim
func ValidatePersistentVolumeClaim(pvc *api.PersistentVolumeClaim) field.ErrorList {
	allErrs := ValidateObjectMeta(&pvc.ObjectMeta, true, ValidatePersistentVolumeName, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidatePersistentVolumeClaimSpec(&pvc.Spec, field.NewPath("spec"))...)
	return allErrs
}

// ValidatePersistentVolumeClaimSpec validates a PersistentVolumeClaimSpec
func ValidatePersistentVolumeClaimSpec(spec *api.PersistentVolumeClaimSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(spec.AccessModes) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("accessModes"), "at least 1 access mode is required"))
	}
	if spec.Selector != nil {
		allErrs = append(allErrs, unversionedvalidation.ValidateLabelSelector(spec.Selector, fldPath.Child("selector"))...)
	}
	for _, mode := range spec.AccessModes {
		if mode != api.ReadWriteOnce && mode != api.ReadOnlyMany && mode != api.ReadWriteMany {
			allErrs = append(allErrs, field.NotSupported(fldPath.Child("accessModes"), mode, supportedAccessModes.List()))
		}
	}
	storageValue, ok := spec.Resources.Requests[api.ResourceStorage]
	if !ok {
		allErrs = append(allErrs, field.Required(fldPath.Child("resources").Key(string(api.ResourceStorage)), ""))
	} else {
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(api.ResourceStorage), storageValue, fldPath.Child("resources").Key(string(api.ResourceStorage)))...)
	}

	if spec.StorageClassName != nil && len(*spec.StorageClassName) > 0 {
		for _, msg := range ValidateClassName(*spec.StorageClassName, false) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("storageClassName"), *spec.StorageClassName, msg))
		}
	}
	return allErrs
}

// ValidatePersistentVolumeClaimUpdate validates an update to a PersistentVolumeClaim
func ValidatePersistentVolumeClaimUpdate(newPvc, oldPvc *api.PersistentVolumeClaim) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newPvc.ObjectMeta, &oldPvc.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidatePersistentVolumeClaim(newPvc)...)
	// PVController needs to update PVC.Spec w/ VolumeName.
	// Claims are immutable in order to enforce quota, range limits, etc. without gaming the system.
	if len(oldPvc.Spec.VolumeName) == 0 {
		// volumeName changes are allowed once.
		// Reset back to empty string after equality check
		oldPvc.Spec.VolumeName = newPvc.Spec.VolumeName
		defer func() { oldPvc.Spec.VolumeName = "" }()
	}

	if utilfeature.DefaultFeatureGate.Enabled(features.ExpandPersistentVolumes) {
		newPVCSpecCopy := newPvc.Spec.DeepCopy()

		// lets make sure storage values are same.
		if newPvc.Status.Phase == api.ClaimBound && newPVCSpecCopy.Resources.Requests != nil {
			newPVCSpecCopy.Resources.Requests["storage"] = oldPvc.Spec.Resources.Requests["storage"]
		}

		oldSize := oldPvc.Spec.Resources.Requests["storage"]
		newSize := newPvc.Spec.Resources.Requests["storage"]

		if !apiequality.Semantic.DeepEqual(*newPVCSpecCopy, oldPvc.Spec) {
			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "is immutable after creation except resources.requests for bound claims"))
		}
		if newSize.Cmp(oldSize) < 0 {
			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec", "resources", "requests", "storage"), "field can not be less than previous value"))
		}

	} else {
		// changes to Spec are not allowed, but updates to label/and some annotations are OK.
		// no-op updates pass validation.
		if !apiequality.Semantic.DeepEqual(newPvc.Spec, oldPvc.Spec) {
			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec"), "field is immutable after creation"))
		}
	}

	// storageclass annotation should be immutable after creation
	// TODO: remove Beta when no longer needed
	allErrs = append(allErrs, ValidateImmutableAnnotation(newPvc.ObjectMeta.Annotations[v1.BetaStorageClassAnnotation], oldPvc.ObjectMeta.Annotations[v1.BetaStorageClassAnnotation], v1.BetaStorageClassAnnotation, field.NewPath("metadata"))...)

	newPvc.Status = oldPvc.Status
	return allErrs
}

// ValidatePersistentVolumeClaimStatusUpdate validates an update to status of a PersistentVolumeClaim
func ValidatePersistentVolumeClaimStatusUpdate(newPvc, oldPvc *api.PersistentVolumeClaim) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newPvc.ObjectMeta, &oldPvc.ObjectMeta, field.NewPath("metadata"))
	if len(newPvc.ResourceVersion) == 0 {
		allErrs = append(allErrs, field.Required(field.NewPath("resourceVersion"), ""))
	}
	if len(newPvc.Spec.AccessModes) == 0 {
		allErrs = append(allErrs, field.Required(field.NewPath("Spec", "accessModes"), ""))
	}
	if !utilfeature.DefaultFeatureGate.Enabled(features.ExpandPersistentVolumes) && len(newPvc.Status.Conditions) > 0 {
		conditionPath := field.NewPath("status", "conditions")
		allErrs = append(allErrs, field.Forbidden(conditionPath, "invalid field"))
	}
	capPath := field.NewPath("status", "capacity")
	for r, qty := range newPvc.Status.Capacity {
		allErrs = append(allErrs, validateBasicResource(qty, capPath.Key(string(r)))...)
	}
	newPvc.Spec = oldPvc.Spec
	return allErrs
}

var supportedPortProtocols = sets.NewString(string(api.ProtocolTCP), string(api.ProtocolUDP))

func validateContainerPorts(ports []api.ContainerPort, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	allNames := sets.String{}
	for i, port := range ports {
		idxPath := fldPath.Index(i)
		if len(port.Name) > 0 {
			if msgs := validation.IsValidPortName(port.Name); len(msgs) != 0 {
				for i = range msgs {
					allErrs = append(allErrs, field.Invalid(idxPath.Child("name"), port.Name, msgs[i]))
				}
			} else if allNames.Has(port.Name) {
				allErrs = append(allErrs, field.Duplicate(idxPath.Child("name"), port.Name))
			} else {
				allNames.Insert(port.Name)
			}
		}
		if port.ContainerPort == 0 {
			allErrs = append(allErrs, field.Required(idxPath.Child("containerPort"), ""))
		} else {
			for _, msg := range validation.IsValidPortNum(int(port.ContainerPort)) {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("containerPort"), port.ContainerPort, msg))
			}
		}
		if port.HostPort != 0 {
			for _, msg := range validation.IsValidPortNum(int(port.HostPort)) {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("hostPort"), port.HostPort, msg))
			}
		}
		if len(port.Protocol) == 0 {
			allErrs = append(allErrs, field.Required(idxPath.Child("protocol"), ""))
		} else if !supportedPortProtocols.Has(string(port.Protocol)) {
			allErrs = append(allErrs, field.NotSupported(idxPath.Child("protocol"), port.Protocol, supportedPortProtocols.List()))
		}
	}
	return allErrs
}

// ValidateEnv validates env vars
func ValidateEnv(vars []api.EnvVar, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	for i, ev := range vars {
		idxPath := fldPath.Index(i)
		if len(ev.Name) == 0 {
			allErrs = append(allErrs, field.Required(idxPath.Child("name"), ""))
		} else {
			for _, msg := range validation.IsEnvVarName(ev.Name) {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("name"), ev.Name, msg))
			}
		}
		allErrs = append(allErrs, validateEnvVarValueFrom(ev, idxPath.Child("valueFrom"))...)
	}
	return allErrs
}

var validFieldPathExpressionsEnv = sets.NewString("metadata.name", "metadata.namespace", "metadata.uid", "spec.nodeName", "spec.serviceAccountName", "status.hostIP", "status.podIP")
var validContainerResourceFieldPathExpressions = sets.NewString("limits.cpu", "limits.memory", "limits.ephemeral-storage", "requests.cpu", "requests.memory", "requests.ephemeral-storage")

func validateEnvVarValueFrom(ev api.EnvVar, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if ev.ValueFrom == nil {
		return allErrs
	}

	numSources := 0

	if ev.ValueFrom.FieldRef != nil {
		numSources++
		allErrs = append(allErrs, validateObjectFieldSelector(ev.ValueFrom.FieldRef, &validFieldPathExpressionsEnv, fldPath.Child("fieldRef"))...)
	}
	if ev.ValueFrom.ResourceFieldRef != nil {
		numSources++
		allErrs = append(allErrs, validateContainerResourceFieldSelector(ev.ValueFrom.ResourceFieldRef, &validContainerResourceFieldPathExpressions, fldPath.Child("resourceFieldRef"), false)...)
	}
	if ev.ValueFrom.ConfigMapKeyRef != nil {
		numSources++
		allErrs = append(allErrs, validateConfigMapKeySelector(ev.ValueFrom.ConfigMapKeyRef, fldPath.Child("configMapKeyRef"))...)
	}
	if ev.ValueFrom.SecretKeyRef != nil {
		numSources++
		allErrs = append(allErrs, validateSecretKeySelector(ev.ValueFrom.SecretKeyRef, fldPath.Child("secretKeyRef"))...)
	}

	if numSources == 0 {
		allErrs = append(allErrs, field.Invalid(fldPath, "", "must specify one of: `fieldRef`, `resourceFieldRef`, `configMapKeyRef` or `secretKeyRef`"))
	} else if len(ev.Value) != 0 {
		if numSources != 0 {
			allErrs = append(allErrs, field.Invalid(fldPath, "", "may not be specified when `value` is not empty"))
		}
	} else if numSources > 1 {
		allErrs = append(allErrs, field.Invalid(fldPath, "", "may not have more than one field specified at a time"))
	}

	return allErrs
}

func validateObjectFieldSelector(fs *api.ObjectFieldSelector, expressions *sets.String, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if len(fs.APIVersion) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("apiVersion"), ""))
	} else if len(fs.FieldPath) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("fieldPath"), ""))
	} else {
		internalFieldPath, _, err := api.Scheme.ConvertFieldLabel(fs.APIVersion, "Pod", fs.FieldPath, "")
		if err != nil {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("fieldPath"), fs.FieldPath, fmt.Sprintf("error converting fieldPath: %v", err)))
		} else if !expressions.Has(internalFieldPath) {
			allErrs = append(allErrs, field.NotSupported(fldPath.Child("fieldPath"), internalFieldPath, expressions.List()))
		}
	}

	return allErrs
}

func fsResourceIsEphemeralStorage(resource string) bool {
	if resource == "limits.ephemeral-storage" || resource == "requests.ephemeral-storage" {
		return true
	}
	return false
}

func validateContainerResourceFieldSelector(fs *api.ResourceFieldSelector, expressions *sets.String, fldPath *field.Path, volume bool) field.ErrorList {
	allErrs := field.ErrorList{}

	if volume && len(fs.ContainerName) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("containerName"), ""))
	} else if len(fs.Resource) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("resource"), ""))
	} else if !expressions.Has(fs.Resource) {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("resource"), fs.Resource, expressions.List()))
	} else if fsResourceIsEphemeralStorage(fs.Resource) && !utilfeature.DefaultFeatureGate.Enabled(features.LocalStorageCapacityIsolation) {
		allErrs = append(allErrs, field.Forbidden(fldPath, "Containers' ephemeral storage requests/limits disabled by feature-gate for Downward API"))
	}
	allErrs = append(allErrs, validateContainerResourceDivisor(fs.Resource, fs.Divisor, fldPath)...)
	return allErrs
}

func ValidateEnvFrom(vars []api.EnvFromSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for i, ev := range vars {
		idxPath := fldPath.Index(i)
		if len(ev.Prefix) > 0 {
			for _, msg := range validation.IsEnvVarName(ev.Prefix) {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("prefix"), ev.Prefix, msg))
			}
		}

		numSources := 0
		if ev.ConfigMapRef != nil {
			numSources++
			allErrs = append(allErrs, validateConfigMapEnvSource(ev.ConfigMapRef, idxPath.Child("configMapRef"))...)
		}
		if ev.SecretRef != nil {
			numSources++
			allErrs = append(allErrs, validateSecretEnvSource(ev.SecretRef, idxPath.Child("secretRef"))...)
		}

		if numSources == 0 {
			allErrs = append(allErrs, field.Invalid(fldPath, "", "must specify one of: `configMapRef` or `secretRef`"))
		} else if numSources > 1 {
			allErrs = append(allErrs, field.Invalid(fldPath, "", "may not have more than one field specified at a time"))
		}
	}
	return allErrs
}

func validateConfigMapEnvSource(configMapSource *api.ConfigMapEnvSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(configMapSource.Name) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
	} else {
		for _, msg := range ValidateConfigMapName(configMapSource.Name, true) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), configMapSource.Name, msg))
		}
	}
	return allErrs
}

func validateSecretEnvSource(secretSource *api.SecretEnvSource, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(secretSource.Name) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
	} else {
		for _, msg := range ValidateSecretName(secretSource.Name, true) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), secretSource.Name, msg))
		}
	}
	return allErrs
}

var validContainerResourceDivisorForCPU = sets.NewString("1m", "1")
var validContainerResourceDivisorForMemory = sets.NewString("1", "1k", "1M", "1G", "1T", "1P", "1E", "1Ki", "1Mi", "1Gi", "1Ti", "1Pi", "1Ei")
var validContainerResourceDivisorForEphemeralStorage = sets.NewString("1", "1k", "1M", "1G", "1T", "1P", "1E", "1Ki", "1Mi", "1Gi", "1Ti", "1Pi", "1Ei")

func validateContainerResourceDivisor(rName string, divisor resource.Quantity, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	unsetDivisor := resource.Quantity{}
	if unsetDivisor.Cmp(divisor) == 0 {
		return allErrs
	}
	switch rName {
	case "limits.cpu", "requests.cpu":
		if !validContainerResourceDivisorForCPU.Has(divisor.String()) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("divisor"), rName, "only divisor's values 1m and 1 are supported with the cpu resource"))
		}
	case "limits.memory", "requests.memory":
		if !validContainerResourceDivisorForMemory.Has(divisor.String()) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("divisor"), rName, "only divisor's values 1, 1k, 1M, 1G, 1T, 1P, 1E, 1Ki, 1Mi, 1Gi, 1Ti, 1Pi, 1Ei are supported with the memory resource"))
		}
	case "limits.ephemeral-storage", "requests.ephemeral-storage":
		if !validContainerResourceDivisorForEphemeralStorage.Has(divisor.String()) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("divisor"), rName, "only divisor's values 1, 1k, 1M, 1G, 1T, 1P, 1E, 1Ki, 1Mi, 1Gi, 1Ti, 1Pi, 1Ei are supported with the local ephemeral storage resource"))
		}
	}
	return allErrs
}

func validateConfigMapKeySelector(s *api.ConfigMapKeySelector, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	nameFn := ValidateNameFunc(ValidateSecretName)
	for _, msg := range nameFn(s.Name, false) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), s.Name, msg))
	}
	if len(s.Key) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("key"), ""))
	} else {
		for _, msg := range validation.IsConfigMapKey(s.Key) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("key"), s.Key, msg))
		}
	}

	return allErrs
}

func validateSecretKeySelector(s *api.SecretKeySelector, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	nameFn := ValidateNameFunc(ValidateSecretName)
	for _, msg := range nameFn(s.Name, false) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), s.Name, msg))
	}
	if len(s.Key) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("key"), ""))
	} else {
		for _, msg := range validation.IsConfigMapKey(s.Key) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("key"), s.Key, msg))
		}
	}

	return allErrs
}

func ValidateVolumeMounts(mounts []api.VolumeMount, volumes sets.String, container *api.Container, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	mountpoints := sets.NewString()

	for i, mnt := range mounts {
		idxPath := fldPath.Index(i)
		if len(mnt.Name) == 0 {
			allErrs = append(allErrs, field.Required(idxPath.Child("name"), ""))
		} else if !volumes.Has(mnt.Name) {
			allErrs = append(allErrs, field.NotFound(idxPath.Child("name"), mnt.Name))
		}
		if len(mnt.MountPath) == 0 {
			allErrs = append(allErrs, field.Required(idxPath.Child("mountPath"), ""))
		}
		if mountpoints.Has(mnt.MountPath) {
			allErrs = append(allErrs, field.Invalid(idxPath.Child("mountPath"), mnt.MountPath, "must be unique"))
		}
		mountpoints.Insert(mnt.MountPath)
		if len(mnt.SubPath) > 0 {
			allErrs = append(allErrs, validateLocalDescendingPath(mnt.SubPath, fldPath.Child("subPath"))...)
		}

		if mnt.MountPropagation != nil {
			allErrs = append(allErrs, validateMountPropagation(mnt.MountPropagation, container, fldPath.Child("mountPropagation"))...)
		}
	}
	return allErrs
}

func validateProbe(probe *api.Probe, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if probe == nil {
		return allErrs
	}
	allErrs = append(allErrs, validateHandler(&probe.Handler, fldPath)...)

	allErrs = append(allErrs, ValidateNonnegativeField(int64(probe.InitialDelaySeconds), fldPath.Child("initialDelaySeconds"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(probe.TimeoutSeconds), fldPath.Child("timeoutSeconds"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(probe.PeriodSeconds), fldPath.Child("periodSeconds"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(probe.SuccessThreshold), fldPath.Child("successThreshold"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(probe.FailureThreshold), fldPath.Child("failureThreshold"))...)
	return allErrs
}

func validateClientIPAffinityConfig(config *api.SessionAffinityConfig, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if config == nil {
		allErrs = append(allErrs, field.Required(fldPath, fmt.Sprintf("when session affinity type is %s", api.ServiceAffinityClientIP)))
		return allErrs
	}
	if config.ClientIP == nil {
		allErrs = append(allErrs, field.Required(fldPath.Child("clientIP"), fmt.Sprintf("when session affinity type is %s", api.ServiceAffinityClientIP)))
		return allErrs
	}
	if config.ClientIP.TimeoutSeconds == nil {
		allErrs = append(allErrs, field.Required(fldPath.Child("clientIP").Child("timeoutSeconds"), fmt.Sprintf("when session affinity type is %s", api.ServiceAffinityClientIP)))
		return allErrs
	}
	allErrs = append(allErrs, validateAffinityTimeout(config.ClientIP.TimeoutSeconds, fldPath.Child("clientIP").Child("timeoutSeconds"))...)

	return allErrs
}

func validateAffinityTimeout(timeout *int32, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if *timeout <= 0 || *timeout > api.MaxClientIPServiceAffinitySeconds {
		allErrs = append(allErrs, field.Invalid(fldPath, timeout, fmt.Sprintf("must be greater than 0 and less than %d", api.MaxClientIPServiceAffinitySeconds)))
	}
	return allErrs
}

// AccumulateUniqueHostPorts extracts each HostPort of each Container,
// accumulating the results and returning an error if any ports conflict.
func AccumulateUniqueHostPorts(containers []api.Container, accumulator *sets.String, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	for ci, ctr := range containers {
		idxPath := fldPath.Index(ci)
		portsPath := idxPath.Child("ports")
		for pi := range ctr.Ports {
			idxPath := portsPath.Index(pi)
			port := ctr.Ports[pi].HostPort
			if port == 0 {
				continue
			}
			str := fmt.Sprintf("%s/%s/%d", ctr.Ports[pi].Protocol, ctr.Ports[pi].HostIP, port)
			if accumulator.Has(str) {
				allErrs = append(allErrs, field.Duplicate(idxPath.Child("hostPort"), str))
			} else {
				accumulator.Insert(str)
			}
		}
	}
	return allErrs
}

// checkHostPortConflicts checks for colliding Port.HostPort values across
// a slice of containers.
func checkHostPortConflicts(containers []api.Container, fldPath *field.Path) field.ErrorList {
	allPorts := sets.String{}
	return AccumulateUniqueHostPorts(containers, &allPorts, fldPath)
}

func validateExecAction(exec *api.ExecAction, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	if len(exec.Command) == 0 {
		allErrors = append(allErrors, field.Required(fldPath.Child("command"), ""))
	}
	return allErrors
}

var supportedHTTPSchemes = sets.NewString(string(api.URISchemeHTTP), string(api.URISchemeHTTPS))

func validateHTTPGetAction(http *api.HTTPGetAction, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	if len(http.Path) == 0 {
		allErrors = append(allErrors, field.Required(fldPath.Child("path"), ""))
	}
	allErrors = append(allErrors, ValidatePortNumOrName(http.Port, fldPath.Child("port"))...)
	if !supportedHTTPSchemes.Has(string(http.Scheme)) {
		allErrors = append(allErrors, field.NotSupported(fldPath.Child("scheme"), http.Scheme, supportedHTTPSchemes.List()))
	}
	for _, header := range http.HTTPHeaders {
		for _, msg := range validation.IsHTTPHeaderName(header.Name) {
			allErrors = append(allErrors, field.Invalid(fldPath.Child("httpHeaders"), header.Name, msg))
		}
	}
	return allErrors
}

func ValidatePortNumOrName(port intstr.IntOrString, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if port.Type == intstr.Int {
		for _, msg := range validation.IsValidPortNum(port.IntValue()) {
			allErrs = append(allErrs, field.Invalid(fldPath, port.IntValue(), msg))
		}
	} else if port.Type == intstr.String {
		for _, msg := range validation.IsValidPortName(port.StrVal) {
			allErrs = append(allErrs, field.Invalid(fldPath, port.StrVal, msg))
		}
	} else {
		allErrs = append(allErrs, field.InternalError(fldPath, fmt.Errorf("unknown type: %v", port.Type)))
	}
	return allErrs
}

func validateTCPSocketAction(tcp *api.TCPSocketAction, fldPath *field.Path) field.ErrorList {
	return ValidatePortNumOrName(tcp.Port, fldPath.Child("port"))
}

func validateHandler(handler *api.Handler, fldPath *field.Path) field.ErrorList {
	numHandlers := 0
	allErrors := field.ErrorList{}
	if handler.Exec != nil {
		if numHandlers > 0 {
			allErrors = append(allErrors, field.Forbidden(fldPath.Child("exec"), "may not specify more than 1 handler type"))
		} else {
			numHandlers++
			allErrors = append(allErrors, validateExecAction(handler.Exec, fldPath.Child("exec"))...)
		}
	}
	if handler.HTTPGet != nil {
		if numHandlers > 0 {
			allErrors = append(allErrors, field.Forbidden(fldPath.Child("httpGet"), "may not specify more than 1 handler type"))
		} else {
			numHandlers++
			allErrors = append(allErrors, validateHTTPGetAction(handler.HTTPGet, fldPath.Child("httpGet"))...)
		}
	}
	if handler.TCPSocket != nil {
		if numHandlers > 0 {
			allErrors = append(allErrors, field.Forbidden(fldPath.Child("tcpSocket"), "may not specify more than 1 handler type"))
		} else {
			numHandlers++
			allErrors = append(allErrors, validateTCPSocketAction(handler.TCPSocket, fldPath.Child("tcpSocket"))...)
		}
	}
	if numHandlers == 0 {
		allErrors = append(allErrors, field.Required(fldPath, "must specify a handler type"))
	}
	return allErrors
}

func validateLifecycle(lifecycle *api.Lifecycle, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if lifecycle.PostStart != nil {
		allErrs = append(allErrs, validateHandler(lifecycle.PostStart, fldPath.Child("postStart"))...)
	}
	if lifecycle.PreStop != nil {
		allErrs = append(allErrs, validateHandler(lifecycle.PreStop, fldPath.Child("preStop"))...)
	}
	return allErrs
}

var supportedPullPolicies = sets.NewString(string(api.PullAlways), string(api.PullIfNotPresent), string(api.PullNever))

func validatePullPolicy(policy api.PullPolicy, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}

	switch policy {
	case api.PullAlways, api.PullIfNotPresent, api.PullNever:
		break
	case "":
		allErrors = append(allErrors, field.Required(fldPath, ""))
	default:
		allErrors = append(allErrors, field.NotSupported(fldPath, policy, supportedPullPolicies.List()))
	}

	return allErrors
}

func validateInitContainers(containers, otherContainers []api.Container, volumes sets.String, fldPath *field.Path) field.ErrorList {
	var allErrs field.ErrorList
	if len(containers) > 0 {
		allErrs = append(allErrs, validateContainers(containers, volumes, fldPath)...)
	}

	allNames := sets.String{}
	for _, ctr := range otherContainers {
		allNames.Insert(ctr.Name)
	}
	for i, ctr := range containers {
		idxPath := fldPath.Index(i)
		if allNames.Has(ctr.Name) {
			allErrs = append(allErrs, field.Duplicate(idxPath.Child("name"), ctr.Name))
		}
		if len(ctr.Name) > 0 {
			allNames.Insert(ctr.Name)
		}
		if ctr.Lifecycle != nil {
			allErrs = append(allErrs, field.Invalid(idxPath.Child("lifecycle"), ctr.Lifecycle, "must not be set for init containers"))
		}
		if ctr.LivenessProbe != nil {
			allErrs = append(allErrs, field.Invalid(idxPath.Child("livenessProbe"), ctr.LivenessProbe, "must not be set for init containers"))
		}
		if ctr.ReadinessProbe != nil {
			allErrs = append(allErrs, field.Invalid(idxPath.Child("readinessProbe"), ctr.ReadinessProbe, "must not be set for init containers"))
		}
	}
	return allErrs
}

func validateContainers(containers []api.Container, volumes sets.String, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if len(containers) == 0 {
		return append(allErrs, field.Required(fldPath, ""))
	}

	allNames := sets.String{}
	for i, ctr := range containers {
		idxPath := fldPath.Index(i)
		namePath := idxPath.Child("name")
		if len(ctr.Name) == 0 {
			allErrs = append(allErrs, field.Required(namePath, ""))
		} else {
			allErrs = append(allErrs, ValidateDNS1123Label(ctr.Name, namePath)...)
		}
		if allNames.Has(ctr.Name) {
			allErrs = append(allErrs, field.Duplicate(namePath, ctr.Name))
		} else {
			allNames.Insert(ctr.Name)
		}
		// TODO: do not validate leading and trailing whitespace to preserve backward compatibility.
		// for example: https://github.com/openshift/origin/issues/14659 image = " " is special token in pod template
		// others may have done similar
		if len(ctr.Image) == 0 {
			allErrs = append(allErrs, field.Required(idxPath.Child("image"), ""))
		}
		if ctr.Lifecycle != nil {
			allErrs = append(allErrs, validateLifecycle(ctr.Lifecycle, idxPath.Child("lifecycle"))...)
		}
		allErrs = append(allErrs, validateProbe(ctr.LivenessProbe, idxPath.Child("livenessProbe"))...)
		// Liveness-specific validation
		if ctr.LivenessProbe != nil && ctr.LivenessProbe.SuccessThreshold != 1 {
			allErrs = append(allErrs, field.Invalid(idxPath.Child("livenessProbe", "successThreshold"), ctr.LivenessProbe.SuccessThreshold, "must be 1"))
		}

		switch ctr.TerminationMessagePolicy {
		case api.TerminationMessageReadFile, api.TerminationMessageFallbackToLogsOnError:
		case "":
			allErrs = append(allErrs, field.Required(idxPath.Child("terminationMessagePolicy"), "must be 'File' or 'FallbackToLogsOnError'"))
		default:
			allErrs = append(allErrs, field.Invalid(idxPath.Child("terminationMessagePolicy"), ctr.TerminationMessagePolicy, "must be 'File' or 'FallbackToLogsOnError'"))
		}

		allErrs = append(allErrs, validateProbe(ctr.ReadinessProbe, idxPath.Child("readinessProbe"))...)
		allErrs = append(allErrs, validateContainerPorts(ctr.Ports, idxPath.Child("ports"))...)
		allErrs = append(allErrs, ValidateEnv(ctr.Env, idxPath.Child("env"))...)
		allErrs = append(allErrs, ValidateEnvFrom(ctr.EnvFrom, idxPath.Child("envFrom"))...)
		allErrs = append(allErrs, ValidateVolumeMounts(ctr.VolumeMounts, volumes, &ctr, idxPath.Child("volumeMounts"))...)
		allErrs = append(allErrs, validatePullPolicy(ctr.ImagePullPolicy, idxPath.Child("imagePullPolicy"))...)
		allErrs = append(allErrs, ValidateResourceRequirements(&ctr.Resources, idxPath.Child("resources"))...)
		allErrs = append(allErrs, ValidateSecurityContext(ctr.SecurityContext, idxPath.Child("securityContext"))...)
	}
	// Check for colliding ports across all containers.
	allErrs = append(allErrs, checkHostPortConflicts(containers, fldPath)...)

	return allErrs
}

func validateRestartPolicy(restartPolicy *api.RestartPolicy, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	switch *restartPolicy {
	case api.RestartPolicyAlways, api.RestartPolicyOnFailure, api.RestartPolicyNever:
		break
	case "":
		allErrors = append(allErrors, field.Required(fldPath, ""))
	default:
		validValues := []string{string(api.RestartPolicyAlways), string(api.RestartPolicyOnFailure), string(api.RestartPolicyNever)}
		allErrors = append(allErrors, field.NotSupported(fldPath, *restartPolicy, validValues))
	}

	return allErrors
}

func validateDNSPolicy(dnsPolicy *api.DNSPolicy, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	switch *dnsPolicy {
	case api.DNSClusterFirstWithHostNet, api.DNSClusterFirst, api.DNSDefault:
		break
	case "":
		allErrors = append(allErrors, field.Required(fldPath, ""))
	default:
		validValues := []string{string(api.DNSClusterFirstWithHostNet), string(api.DNSClusterFirst), string(api.DNSDefault)}
		allErrors = append(allErrors, field.NotSupported(fldPath, dnsPolicy, validValues))
	}
	return allErrors
}

func validateHostNetwork(hostNetwork bool, containers []api.Container, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	if hostNetwork {
		for i, container := range containers {
			portsPath := fldPath.Index(i).Child("ports")
			for i, port := range container.Ports {
				idxPath := portsPath.Index(i)
				if port.HostPort != port.ContainerPort {
					allErrors = append(allErrors, field.Invalid(idxPath.Child("containerPort"), port.ContainerPort, "must match `hostPort` when `hostNetwork` is true"))
				}
			}
		}
	}
	return allErrors
}

// validateImagePullSecrets checks to make sure the pull secrets are well
// formed.  Right now, we only expect name to be set (it's the only field).  If
// this ever changes and someone decides to set those fields, we'd like to
// know.
func validateImagePullSecrets(imagePullSecrets []api.LocalObjectReference, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	for i, currPullSecret := range imagePullSecrets {
		idxPath := fldPath.Index(i)
		strippedRef := api.LocalObjectReference{Name: currPullSecret.Name}
		if !reflect.DeepEqual(strippedRef, currPullSecret) {
			allErrors = append(allErrors, field.Invalid(idxPath, currPullSecret, "only name may be set"))
		}
	}
	return allErrors
}

// validateAffinity checks if given affinities are valid
func validateAffinity(affinity *api.Affinity, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if affinity != nil {
		if na := affinity.NodeAffinity; na != nil {
			// TODO: Uncomment the next three lines once RequiredDuringSchedulingRequiredDuringExecution is implemented.
			// if na.RequiredDuringSchedulingRequiredDuringExecution != nil {
			//	allErrs = append(allErrs, ValidateNodeSelector(na.RequiredDuringSchedulingRequiredDuringExecution, fldPath.Child("requiredDuringSchedulingRequiredDuringExecution"))...)
			// }

			if na.RequiredDuringSchedulingIgnoredDuringExecution != nil {
				allErrs = append(allErrs, ValidateNodeSelector(na.RequiredDuringSchedulingIgnoredDuringExecution, fldPath.Child("requiredDuringSchedulingIgnoredDuringExecution"))...)
			}

			if len(na.PreferredDuringSchedulingIgnoredDuringExecution) > 0 {
				allErrs = append(allErrs, ValidatePreferredSchedulingTerms(na.PreferredDuringSchedulingIgnoredDuringExecution, fldPath.Child("preferredDuringSchedulingIgnoredDuringExecution"))...)
			}
		}
		if affinity.PodAffinity != nil {
			allErrs = append(allErrs, validatePodAffinity(affinity.PodAffinity, fldPath.Child("podAffinity"))...)
		}
		if affinity.PodAntiAffinity != nil {
			allErrs = append(allErrs, validatePodAntiAffinity(affinity.PodAntiAffinity, fldPath.Child("podAntiAffinity"))...)
		}
	}

	return allErrs
}

func validateTaintEffect(effect *api.TaintEffect, allowEmpty bool, fldPath *field.Path) field.ErrorList {
	if !allowEmpty && len(*effect) == 0 {
		return field.ErrorList{field.Required(fldPath, "")}
	}

	allErrors := field.ErrorList{}
	switch *effect {
	// TODO: Replace next line with subsequent commented-out line when implement TaintEffectNoScheduleNoAdmit.
	case api.TaintEffectNoSchedule, api.TaintEffectPreferNoSchedule, api.TaintEffectNoExecute:
		// case api.TaintEffectNoSchedule, api.TaintEffectPreferNoSchedule, api.TaintEffectNoScheduleNoAdmit, api.TaintEffectNoExecute:
	default:
		validValues := []string{
			string(api.TaintEffectNoSchedule),
			string(api.TaintEffectPreferNoSchedule),
			string(api.TaintEffectNoExecute),
			// TODO: Uncomment this block when implement TaintEffectNoScheduleNoAdmit.
			// string(api.TaintEffectNoScheduleNoAdmit),
		}
		allErrors = append(allErrors, field.NotSupported(fldPath, effect, validValues))
	}
	return allErrors
}

// validateOnlyAddedTolerations validates updated pod tolerations.
func validateOnlyAddedTolerations(newTolerations []api.Toleration, oldTolerations []api.Toleration, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for _, old := range oldTolerations {
		found := false
		old.TolerationSeconds = nil
		for _, new := range newTolerations {
			new.TolerationSeconds = nil
			if reflect.DeepEqual(old, new) {
				found = true
				break
			}
		}
		if !found {
			allErrs = append(allErrs, field.Forbidden(fldPath, "existing toleration can not be modified except its tolerationSeconds"))
			return allErrs
		}
	}

	allErrs = append(allErrs, ValidateTolerations(newTolerations, fldPath)...)
	return allErrs
}

func ValidateHostAliases(hostAliases []api.HostAlias, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for _, hostAlias := range hostAliases {
		if ip := net.ParseIP(hostAlias.IP); ip == nil {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("ip"), hostAlias.IP, "must be valid IP address"))
		}
		for _, hostname := range hostAlias.Hostnames {
			allErrs = append(allErrs, ValidateDNS1123Subdomain(hostname, fldPath.Child("hostnames"))...)
		}
	}
	return allErrs
}

// ValidateTolerations tests if given tolerations have valid data.
func ValidateTolerations(tolerations []api.Toleration, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	for i, toleration := range tolerations {
		idxPath := fldPath.Index(i)
		// validate the toleration key
		if len(toleration.Key) > 0 {
			allErrors = append(allErrors, unversionedvalidation.ValidateLabelName(toleration.Key, idxPath.Child("key"))...)
		}

		// empty toleration key with Exists operator and empty value means match all taints
		if len(toleration.Key) == 0 && toleration.Operator != api.TolerationOpExists {
			allErrors = append(allErrors, field.Invalid(idxPath.Child("operator"), toleration.Operator,
				"operator must be Exists when `key` is empty, which means \"match all values and all keys\""))
		}

		if toleration.TolerationSeconds != nil && toleration.Effect != api.TaintEffectNoExecute {
			allErrors = append(allErrors, field.Invalid(idxPath.Child("effect"), toleration.Effect,
				"effect must be 'NoExecute' when `tolerationSeconds` is set"))
		}

		// validate toleration operator and value
		switch toleration.Operator {
		// empty operator means Equal
		case api.TolerationOpEqual, "":
			if errs := validation.IsValidLabelValue(toleration.Value); len(errs) != 0 {
				allErrors = append(allErrors, field.Invalid(idxPath.Child("operator"), toleration.Value, strings.Join(errs, ";")))
			}
		case api.TolerationOpExists:
			if len(toleration.Value) > 0 {
				allErrors = append(allErrors, field.Invalid(idxPath.Child("operator"), toleration, "value must be empty when `operator` is 'Exists'"))
			}
		default:
			validValues := []string{string(api.TolerationOpEqual), string(api.TolerationOpExists)}
			allErrors = append(allErrors, field.NotSupported(idxPath.Child("operator"), toleration.Operator, validValues))
		}

		// validate toleration effect, empty toleration effect means match all taint effects
		if len(toleration.Effect) > 0 {
			allErrors = append(allErrors, validateTaintEffect(&toleration.Effect, true, idxPath.Child("effect"))...)
		}
	}
	return allErrors
}

func toResourceNames(resources api.ResourceList) []api.ResourceName {
	result := []api.ResourceName{}
	for resourceName := range resources {
		result = append(result, resourceName)
	}
	return result
}

func toSet(resourceNames []api.ResourceName) sets.String {
	result := sets.NewString()
	for _, resourceName := range resourceNames {
		result.Insert(string(resourceName))
	}
	return result
}

func toContainerResourcesSet(ctr *api.Container) sets.String {
	resourceNames := toResourceNames(ctr.Resources.Requests)
	resourceNames = append(resourceNames, toResourceNames(ctr.Resources.Limits)...)
	return toSet(resourceNames)
}

// validateContainersOnlyForPod does additional validation for containers on a pod versus a pod template
// it only does additive validation of fields not covered in validateContainers
func validateContainersOnlyForPod(containers []api.Container, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for i, ctr := range containers {
		idxPath := fldPath.Index(i)
		if len(ctr.Image) != len(strings.TrimSpace(ctr.Image)) {
			allErrs = append(allErrs, field.Invalid(idxPath.Child("image"), ctr.Image, "must not have leading or trailing whitespace"))
		}
	}
	return allErrs
}

// ValidatePod tests if required fields in the pod are set.
func ValidatePod(pod *api.Pod) field.ErrorList {
	fldPath := field.NewPath("metadata")
	allErrs := ValidateObjectMeta(&pod.ObjectMeta, true, ValidatePodName, fldPath)
	allErrs = append(allErrs, ValidatePodSpecificAnnotations(pod.ObjectMeta.Annotations, &pod.Spec, fldPath.Child("annotations"))...)
	allErrs = append(allErrs, ValidatePodSpec(&pod.Spec, field.NewPath("spec"))...)

	// we do additional validation only pertinent for pods and not pod templates
	// this was done to preserve backwards compatibility
	specPath := field.NewPath("spec")

	allErrs = append(allErrs, validateContainersOnlyForPod(pod.Spec.Containers, specPath.Child("containers"))...)
	allErrs = append(allErrs, validateContainersOnlyForPod(pod.Spec.InitContainers, specPath.Child("initContainers"))...)

	if utilfeature.DefaultFeatureGate.Enabled(features.HugePages) {
		hugePageResources := sets.NewString()
		for i := range pod.Spec.Containers {
			resourceSet := toContainerResourcesSet(&pod.Spec.Containers[i])
			for resourceStr := range resourceSet {
				if v1helper.IsHugePageResourceName(v1.ResourceName(resourceStr)) {
					hugePageResources.Insert(resourceStr)
				}
			}
		}
		if len(hugePageResources) > 1 {
			allErrs = append(allErrs, field.Invalid(specPath, hugePageResources, "must use a single hugepage size in a pod spec"))
		}
	}

	return allErrs
}

// ValidatePodSpec tests that the specified PodSpec has valid data.
// This includes checking formatting and uniqueness.  It also canonicalizes the
// structure by setting default values and implementing any backwards-compatibility
// tricks.
func ValidatePodSpec(spec *api.PodSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	allVolumes, vErrs := ValidateVolumes(spec.Volumes, fldPath.Child("volumes"))
	allErrs = append(allErrs, vErrs...)
	allErrs = append(allErrs, validateContainers(spec.Containers, allVolumes, fldPath.Child("containers"))...)
	allErrs = append(allErrs, validateInitContainers(spec.InitContainers, spec.Containers, allVolumes, fldPath.Child("initContainers"))...)
	allErrs = append(allErrs, validateRestartPolicy(&spec.RestartPolicy, fldPath.Child("restartPolicy"))...)
	allErrs = append(allErrs, validateDNSPolicy(&spec.DNSPolicy, fldPath.Child("dnsPolicy"))...)
	allErrs = append(allErrs, unversionedvalidation.ValidateLabels(spec.NodeSelector, fldPath.Child("nodeSelector"))...)
	allErrs = append(allErrs, ValidatePodSecurityContext(spec.SecurityContext, spec, fldPath, fldPath.Child("securityContext"))...)
	allErrs = append(allErrs, validateImagePullSecrets(spec.ImagePullSecrets, fldPath.Child("imagePullSecrets"))...)
	allErrs = append(allErrs, validateAffinity(spec.Affinity, fldPath.Child("affinity"))...)
	if len(spec.ServiceAccountName) > 0 {
		for _, msg := range ValidateServiceAccountName(spec.ServiceAccountName, false) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("serviceAccountName"), spec.ServiceAccountName, msg))
		}
	}

	if len(spec.NodeName) > 0 {
		for _, msg := range ValidateNodeName(spec.NodeName, false) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("nodeName"), spec.NodeName, msg))
		}
	}

	if spec.ActiveDeadlineSeconds != nil {
		value := *spec.ActiveDeadlineSeconds
		if value < 1 || value > math.MaxInt32 {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("activeDeadlineSeconds"), value, validation.InclusiveRangeError(1, math.MaxInt32)))
		}
	}

	if len(spec.Hostname) > 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(spec.Hostname, fldPath.Child("hostname"))...)
	}

	if len(spec.Subdomain) > 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(spec.Subdomain, fldPath.Child("subdomain"))...)
	}

	if len(spec.Tolerations) > 0 {
		allErrs = append(allErrs, ValidateTolerations(spec.Tolerations, fldPath.Child("tolerations"))...)
	}

	if len(spec.HostAliases) > 0 {
		allErrs = append(allErrs, ValidateHostAliases(spec.HostAliases, fldPath.Child("hostAliases"))...)
	}

	if len(spec.PriorityClassName) > 0 {
		if !utilfeature.DefaultFeatureGate.Enabled(features.PodPriority) {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("priorityClassName"), "Pod priority is disabled by feature-gate"))
		} else {
			for _, msg := range ValidatePriorityClassName(spec.PriorityClassName, false) {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("priorityClassName"), spec.PriorityClassName, msg))
			}
		}
	}

	if spec.Priority != nil && !utilfeature.DefaultFeatureGate.Enabled(features.PodPriority) {
		allErrs = append(allErrs, field.Forbidden(fldPath.Child("priority"), "Pod priority is disabled by feature-gate"))
	}

	return allErrs
}

// ValidateNodeSelectorRequirement tests that the specified NodeSelectorRequirement fields has valid data
func ValidateNodeSelectorRequirement(rq api.NodeSelectorRequirement, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	switch rq.Operator {
	case api.NodeSelectorOpIn, api.NodeSelectorOpNotIn:
		if len(rq.Values) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Child("values"), "must be specified when `operator` is 'In' or 'NotIn'"))
		}
	case api.NodeSelectorOpExists, api.NodeSelectorOpDoesNotExist:
		if len(rq.Values) > 0 {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("values"), "may not be specified when `operator` is 'Exists' or 'DoesNotExist'"))
		}

	case api.NodeSelectorOpGt, api.NodeSelectorOpLt:
		if len(rq.Values) != 1 {
			allErrs = append(allErrs, field.Required(fldPath.Child("values"), "must be specified single value when `operator` is 'Lt' or 'Gt'"))
		}
	default:
		allErrs = append(allErrs, field.Invalid(fldPath.Child("operator"), rq.Operator, "not a valid selector operator"))
	}
	allErrs = append(allErrs, unversionedvalidation.ValidateLabelName(rq.Key, fldPath.Child("key"))...)
	return allErrs
}

// ValidateNodeSelectorTerm tests that the specified node selector term has valid data
func ValidateNodeSelectorTerm(term api.NodeSelectorTerm, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if len(term.MatchExpressions) == 0 {
		return append(allErrs, field.Required(fldPath.Child("matchExpressions"), "must have at least one node selector requirement"))
	}
	for j, req := range term.MatchExpressions {
		allErrs = append(allErrs, ValidateNodeSelectorRequirement(req, fldPath.Child("matchExpressions").Index(j))...)
	}
	return allErrs
}

// ValidateNodeSelector tests that the specified nodeSelector fields has valid data
func ValidateNodeSelector(nodeSelector *api.NodeSelector, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	termFldPath := fldPath.Child("nodeSelectorTerms")
	if len(nodeSelector.NodeSelectorTerms) == 0 {
		return append(allErrs, field.Required(termFldPath, "must have at least one node selector term"))
	}

	for i, term := range nodeSelector.NodeSelectorTerms {
		allErrs = append(allErrs, ValidateNodeSelectorTerm(term, termFldPath.Index(i))...)
	}

	return allErrs
}

// ValidateAvoidPodsInNodeAnnotations tests that the serialized AvoidPods in Node.Annotations has valid data
func ValidateAvoidPodsInNodeAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	v1Avoids, err := v1helper.GetAvoidPodsFromNodeAnnotations(annotations)
	if err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("AvoidPods"), api.PreferAvoidPodsAnnotationKey, err.Error()))
		return allErrs
	}
	var avoids api.AvoidPods
	if err := k8s_api_v1.Convert_v1_AvoidPods_To_api_AvoidPods(&v1Avoids, &avoids, nil); err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("AvoidPods"), api.PreferAvoidPodsAnnotationKey, err.Error()))
		return allErrs
	}

	if len(avoids.PreferAvoidPods) != 0 {
		for i, pa := range avoids.PreferAvoidPods {
			idxPath := fldPath.Child(api.PreferAvoidPodsAnnotationKey).Index(i)
			allErrs = append(allErrs, validatePreferAvoidPodsEntry(pa, idxPath)...)
		}
	}

	return allErrs
}

// validatePreferAvoidPodsEntry tests if given PreferAvoidPodsEntry has valid data.
func validatePreferAvoidPodsEntry(avoidPodEntry api.PreferAvoidPodsEntry, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}
	if avoidPodEntry.PodSignature.PodController == nil {
		allErrors = append(allErrors, field.Required(fldPath.Child("PodSignature"), ""))
	} else {
		if *(avoidPodEntry.PodSignature.PodController.Controller) != true {
			allErrors = append(allErrors,
				field.Invalid(fldPath.Child("PodSignature").Child("PodController").Child("Controller"),
					*(avoidPodEntry.PodSignature.PodController.Controller), "must point to a controller"))
		}
	}
	return allErrors
}

// ValidatePreferredSchedulingTerms tests that the specified SoftNodeAffinity fields has valid data
func ValidatePreferredSchedulingTerms(terms []api.PreferredSchedulingTerm, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	for i, term := range terms {
		if term.Weight <= 0 || term.Weight > 100 {
			allErrs = append(allErrs, field.Invalid(fldPath.Index(i).Child("weight"), term.Weight, "must be in the range 1-100"))
		}

		allErrs = append(allErrs, ValidateNodeSelectorTerm(term.Preference, fldPath.Index(i).Child("preference"))...)
	}
	return allErrs
}

// validatePodAffinityTerm tests that the specified podAffinityTerm fields have valid data
func validatePodAffinityTerm(podAffinityTerm api.PodAffinityTerm, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	allErrs = append(allErrs, unversionedvalidation.ValidateLabelSelector(podAffinityTerm.LabelSelector, fldPath.Child("matchExpressions"))...)
	for _, name := range podAffinityTerm.Namespaces {
		for _, msg := range ValidateNamespaceName(name, false) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("namespace"), name, msg))
		}
	}
	if len(podAffinityTerm.TopologyKey) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("topologyKey"), "can not be empty"))
	}
	return append(allErrs, unversionedvalidation.ValidateLabelName(podAffinityTerm.TopologyKey, fldPath.Child("topologyKey"))...)
}

// validatePodAffinityTerms tests that the specified podAffinityTerms fields have valid data
func validatePodAffinityTerms(podAffinityTerms []api.PodAffinityTerm, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for i, podAffinityTerm := range podAffinityTerms {
		allErrs = append(allErrs, validatePodAffinityTerm(podAffinityTerm, fldPath.Index(i))...)
	}
	return allErrs
}

// validateWeightedPodAffinityTerms tests that the specified weightedPodAffinityTerms fields have valid data
func validateWeightedPodAffinityTerms(weightedPodAffinityTerms []api.WeightedPodAffinityTerm, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for j, weightedTerm := range weightedPodAffinityTerms {
		if weightedTerm.Weight <= 0 || weightedTerm.Weight > 100 {
			allErrs = append(allErrs, field.Invalid(fldPath.Index(j).Child("weight"), weightedTerm.Weight, "must be in the range 1-100"))
		}
		allErrs = append(allErrs, validatePodAffinityTerm(weightedTerm.PodAffinityTerm, fldPath.Index(j).Child("podAffinityTerm"))...)
	}
	return allErrs
}

// validatePodAntiAffinity tests that the specified podAntiAffinity fields have valid data
func validatePodAntiAffinity(podAntiAffinity *api.PodAntiAffinity, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	// TODO:Uncomment below code once RequiredDuringSchedulingRequiredDuringExecution is implemented.
	// if podAntiAffinity.RequiredDuringSchedulingRequiredDuringExecution != nil {
	//	allErrs = append(allErrs, validatePodAffinityTerms(podAntiAffinity.RequiredDuringSchedulingRequiredDuringExecution, false,
	//		fldPath.Child("requiredDuringSchedulingRequiredDuringExecution"))...)
	//}
	if podAntiAffinity.RequiredDuringSchedulingIgnoredDuringExecution != nil {
		allErrs = append(allErrs, validatePodAffinityTerms(podAntiAffinity.RequiredDuringSchedulingIgnoredDuringExecution,
			fldPath.Child("requiredDuringSchedulingIgnoredDuringExecution"))...)
	}
	if podAntiAffinity.PreferredDuringSchedulingIgnoredDuringExecution != nil {
		allErrs = append(allErrs, validateWeightedPodAffinityTerms(podAntiAffinity.PreferredDuringSchedulingIgnoredDuringExecution,
			fldPath.Child("preferredDuringSchedulingIgnoredDuringExecution"))...)
	}
	return allErrs
}

// validatePodAffinity tests that the specified podAffinity fields have valid data
func validatePodAffinity(podAffinity *api.PodAffinity, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	// TODO:Uncomment below code once RequiredDuringSchedulingRequiredDuringExecution is implemented.
	// if podAffinity.RequiredDuringSchedulingRequiredDuringExecution != nil {
	//	allErrs = append(allErrs, validatePodAffinityTerms(podAffinity.RequiredDuringSchedulingRequiredDuringExecution, false,
	//		fldPath.Child("requiredDuringSchedulingRequiredDuringExecution"))...)
	//}
	if podAffinity.RequiredDuringSchedulingIgnoredDuringExecution != nil {
		allErrs = append(allErrs, validatePodAffinityTerms(podAffinity.RequiredDuringSchedulingIgnoredDuringExecution,
			fldPath.Child("requiredDuringSchedulingIgnoredDuringExecution"))...)
	}
	if podAffinity.PreferredDuringSchedulingIgnoredDuringExecution != nil {
		allErrs = append(allErrs, validateWeightedPodAffinityTerms(podAffinity.PreferredDuringSchedulingIgnoredDuringExecution,
			fldPath.Child("preferredDuringSchedulingIgnoredDuringExecution"))...)
	}
	return allErrs
}

func ValidateSeccompProfile(p string, fldPath *field.Path) field.ErrorList {
	if p == "docker/default" {
		return nil
	}
	if p == "unconfined" {
		return nil
	}
	if strings.HasPrefix(p, "localhost/") {
		return validateLocalDescendingPath(strings.TrimPrefix(p, "localhost/"), fldPath)
	}
	return field.ErrorList{field.Invalid(fldPath, p, "must be a valid seccomp profile")}
}

func ValidateSeccompPodAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if p, exists := annotations[api.SeccompPodAnnotationKey]; exists {
		allErrs = append(allErrs, ValidateSeccompProfile(p, fldPath.Child(api.SeccompPodAnnotationKey))...)
	}
	for k, p := range annotations {
		if strings.HasPrefix(k, api.SeccompContainerAnnotationKeyPrefix) {
			allErrs = append(allErrs, ValidateSeccompProfile(p, fldPath.Child(k))...)
		}
	}

	return allErrs
}

func ValidateAppArmorPodAnnotations(annotations map[string]string, spec *api.PodSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for k, p := range annotations {
		if !strings.HasPrefix(k, apparmor.ContainerAnnotationKeyPrefix) {
			continue
		}
		// TODO: this belongs to admission, not general pod validation:
		if !utilfeature.DefaultFeatureGate.Enabled(features.AppArmor) {
			allErrs = append(allErrs, field.Forbidden(fldPath.Key(k), "AppArmor is disabled by feature-gate"))
			continue
		}
		containerName := strings.TrimPrefix(k, apparmor.ContainerAnnotationKeyPrefix)
		if !podSpecHasContainer(spec, containerName) {
			allErrs = append(allErrs, field.Invalid(fldPath.Key(k), containerName, "container not found"))
		}

		if err := apparmor.ValidateProfileFormat(p); err != nil {
			allErrs = append(allErrs, field.Invalid(fldPath.Key(k), p, err.Error()))
		}
	}

	return allErrs
}

func podSpecHasContainer(spec *api.PodSpec, containerName string) bool {
	for _, c := range spec.InitContainers {
		if c.Name == containerName {
			return true
		}
	}
	for _, c := range spec.Containers {
		if c.Name == containerName {
			return true
		}
	}
	return false
}

const (
	// a sysctl segment regex, concatenated with dots to form a sysctl name
	SysctlSegmentFmt string = "[a-z0-9]([-_a-z0-9]*[a-z0-9])?"

	// a sysctl name regex
	SysctlFmt string = "(" + SysctlSegmentFmt + "\\.)*" + SysctlSegmentFmt

	// the maximal length of a sysctl name
	SysctlMaxLength int = 253
)

var sysctlRegexp = regexp.MustCompile("^" + SysctlFmt + "$")

// IsValidSysctlName checks that the given string is a valid sysctl name,
// i.e. matches SysctlFmt.
func IsValidSysctlName(name string) bool {
	if len(name) > SysctlMaxLength {
		return false
	}
	return sysctlRegexp.MatchString(name)
}

func validateSysctls(sysctls []api.Sysctl, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for i, s := range sysctls {
		if len(s.Name) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Index(i).Child("name"), ""))
		} else if !IsValidSysctlName(s.Name) {
			allErrs = append(allErrs, field.Invalid(fldPath.Index(i).Child("name"), s.Name, fmt.Sprintf("must have at most %d characters and match regex %s", SysctlMaxLength, SysctlFmt)))
		}
	}
	return allErrs
}

// ValidatePodSecurityContext test that the specified PodSecurityContext has valid data.
func ValidatePodSecurityContext(securityContext *api.PodSecurityContext, spec *api.PodSpec, specPath, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if securityContext != nil {
		allErrs = append(allErrs, validateHostNetwork(securityContext.HostNetwork, spec.Containers, specPath.Child("containers"))...)
		if securityContext.FSGroup != nil {
			for _, msg := range validation.IsValidGroupID(*securityContext.FSGroup) {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("fsGroup"), *(securityContext.FSGroup), msg))
			}
		}
		if securityContext.RunAsUser != nil {
			for _, msg := range validation.IsValidUserID(*securityContext.RunAsUser) {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("runAsUser"), *(securityContext.RunAsUser), msg))
			}
		}
		for g, gid := range securityContext.SupplementalGroups {
			for _, msg := range validation.IsValidGroupID(gid) {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("supplementalGroups").Index(g), gid, msg))
			}
		}
	}

	return allErrs
}

func ValidateContainerUpdates(newContainers, oldContainers []api.Container, fldPath *field.Path) (allErrs field.ErrorList, stop bool) {
	allErrs = field.ErrorList{}
	if len(newContainers) != len(oldContainers) {
		//TODO: Pinpoint the specific container that causes the invalid error after we have strategic merge diff
		allErrs = append(allErrs, field.Forbidden(fldPath, "pod updates may not add or remove containers"))
		return allErrs, true
	}

	// validate updated container images
	for i, ctr := range newContainers {
		if len(ctr.Image) == 0 {
			allErrs = append(allErrs, field.Required(fldPath.Index(i).Child("image"), ""))
		}
		// this is only called from ValidatePodUpdate so its safe to check leading/trailing whitespace.
		if len(strings.TrimSpace(ctr.Image)) != len(ctr.Image) {
			allErrs = append(allErrs, field.Invalid(fldPath.Index(i).Child("image"), ctr.Image, "must not have leading or trailing whitespace"))
		}
	}
	return allErrs, false
}

// ValidatePodUpdate tests to see if the update is legal for an end user to make. newPod is updated with fields
// that cannot be changed.
func ValidatePodUpdate(newPod, oldPod *api.Pod) field.ErrorList {
	fldPath := field.NewPath("metadata")
	allErrs := ValidateObjectMetaUpdate(&newPod.ObjectMeta, &oldPod.ObjectMeta, fldPath)
	allErrs = append(allErrs, ValidatePodSpecificAnnotationUpdates(newPod, oldPod, fldPath.Child("annotations"))...)
	specPath := field.NewPath("spec")

	// validate updateable fields:
	// 1.  spec.containers[*].image
	// 2.  spec.initContainers[*].image
	// 3.  spec.activeDeadlineSeconds

	containerErrs, stop := ValidateContainerUpdates(newPod.Spec.Containers, oldPod.Spec.Containers, specPath.Child("containers"))
	allErrs = append(allErrs, containerErrs...)
	if stop {
		return allErrs
	}
	containerErrs, stop = ValidateContainerUpdates(newPod.Spec.InitContainers, oldPod.Spec.InitContainers, specPath.Child("initContainers"))
	allErrs = append(allErrs, containerErrs...)
	if stop {
		return allErrs
	}

	// validate updated spec.activeDeadlineSeconds.  two types of updates are allowed:
	// 1.  from nil to a positive value
	// 2.  from a positive value to a lesser, non-negative value
	if newPod.Spec.ActiveDeadlineSeconds != nil {
		newActiveDeadlineSeconds := *newPod.Spec.ActiveDeadlineSeconds
		if newActiveDeadlineSeconds < 0 || newActiveDeadlineSeconds > math.MaxInt32 {
			allErrs = append(allErrs, field.Invalid(specPath.Child("activeDeadlineSeconds"), newActiveDeadlineSeconds, validation.InclusiveRangeError(0, math.MaxInt32)))
			return allErrs
		}
		if oldPod.Spec.ActiveDeadlineSeconds != nil {
			oldActiveDeadlineSeconds := *oldPod.Spec.ActiveDeadlineSeconds
			if oldActiveDeadlineSeconds < newActiveDeadlineSeconds {
				allErrs = append(allErrs, field.Invalid(specPath.Child("activeDeadlineSeconds"), newActiveDeadlineSeconds, "must be less than or equal to previous value"))
				return allErrs
			}
		}
	} else if oldPod.Spec.ActiveDeadlineSeconds != nil {
		allErrs = append(allErrs, field.Invalid(specPath.Child("activeDeadlineSeconds"), newPod.Spec.ActiveDeadlineSeconds, "must not update from a positive integer to nil value"))
	}

	// handle updateable fields by munging those fields prior to deep equal comparison.
	mungedPod := *newPod
	// munge spec.containers[*].image
	var newContainers []api.Container
	for ix, container := range mungedPod.Spec.Containers {
		container.Image = oldPod.Spec.Containers[ix].Image
		newContainers = append(newContainers, container)
	}
	mungedPod.Spec.Containers = newContainers
	// munge spec.initContainers[*].image
	var newInitContainers []api.Container
	for ix, container := range mungedPod.Spec.InitContainers {
		container.Image = oldPod.Spec.InitContainers[ix].Image
		newInitContainers = append(newInitContainers, container)
	}
	mungedPod.Spec.InitContainers = newInitContainers
	// munge spec.activeDeadlineSeconds
	mungedPod.Spec.ActiveDeadlineSeconds = nil
	if oldPod.Spec.ActiveDeadlineSeconds != nil {
		activeDeadlineSeconds := *oldPod.Spec.ActiveDeadlineSeconds
		mungedPod.Spec.ActiveDeadlineSeconds = &activeDeadlineSeconds
	}

	// Allow only additions to tolerations updates.
	mungedPod.Spec.Tolerations = oldPod.Spec.Tolerations
	allErrs = append(allErrs, validateOnlyAddedTolerations(newPod.Spec.Tolerations, oldPod.Spec.Tolerations, specPath.Child("tolerations"))...)

	if !apiequality.Semantic.DeepEqual(mungedPod.Spec, oldPod.Spec) {
		// This diff isn't perfect, but it's a helluva lot better an "I'm not going to tell you what the difference is".
		//TODO: Pinpoint the specific field that causes the invalid error after we have strategic merge diff
		specDiff := diff.ObjectDiff(mungedPod.Spec, oldPod.Spec)
		allErrs = append(allErrs, field.Forbidden(specPath, fmt.Sprintf("pod updates may not change fields other than `spec.containers[*].image`, `spec.initContainers[*].image`, `spec.activeDeadlineSeconds` or `spec.tolerations` (only additions to existing tolerations)\n%v", specDiff)))
	}

	return allErrs
}

// ValidatePodStatusUpdate tests to see if the update is legal for an end user to make. newPod is updated with fields
// that cannot be changed.
func ValidatePodStatusUpdate(newPod, oldPod *api.Pod) field.ErrorList {
	fldPath := field.NewPath("metadata")
	allErrs := ValidateObjectMetaUpdate(&newPod.ObjectMeta, &oldPod.ObjectMeta, fldPath)
	allErrs = append(allErrs, ValidatePodSpecificAnnotationUpdates(newPod, oldPod, fldPath.Child("annotations"))...)

	if newPod.Spec.NodeName != oldPod.Spec.NodeName {
		allErrs = append(allErrs, field.Forbidden(field.NewPath("status", "nodeName"), "may not be changed directly"))
	}

	// For status update we ignore changes to pod spec.
	newPod.Spec = oldPod.Spec

	return allErrs
}

// ValidatePodBinding tests if required fields in the pod binding are legal.
func ValidatePodBinding(binding *api.Binding) field.ErrorList {
	allErrs := field.ErrorList{}

	if len(binding.Target.Kind) != 0 && binding.Target.Kind != "Node" {
		// TODO: When validation becomes versioned, this gets more complicated.
		allErrs = append(allErrs, field.NotSupported(field.NewPath("target", "kind"), binding.Target.Kind, []string{"Node", "<empty>"}))
	}
	if len(binding.Target.Name) == 0 {
		// TODO: When validation becomes versioned, this gets more complicated.
		allErrs = append(allErrs, field.Required(field.NewPath("target", "name"), ""))
	}

	return allErrs
}

// ValidatePodTemplate tests if required fields in the pod template are set.
func ValidatePodTemplate(pod *api.PodTemplate) field.ErrorList {
	allErrs := ValidateObjectMeta(&pod.ObjectMeta, true, ValidatePodName, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidatePodTemplateSpec(&pod.Template, field.NewPath("template"))...)
	return allErrs
}

// ValidatePodTemplateUpdate tests to see if the update is legal for an end user to make. newPod is updated with fields
// that cannot be changed.
func ValidatePodTemplateUpdate(newPod, oldPod *api.PodTemplate) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&oldPod.ObjectMeta, &newPod.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidatePodTemplateSpec(&newPod.Template, field.NewPath("template"))...)
	return allErrs
}

var supportedSessionAffinityType = sets.NewString(string(api.ServiceAffinityClientIP), string(api.ServiceAffinityNone))
var supportedServiceType = sets.NewString(string(api.ServiceTypeClusterIP), string(api.ServiceTypeNodePort),
	string(api.ServiceTypeLoadBalancer), string(api.ServiceTypeExternalName))

// ValidateService tests if required fields/annotations of a Service are valid.
func ValidateService(service *api.Service) field.ErrorList {
	allErrs := ValidateObjectMeta(&service.ObjectMeta, true, ValidateServiceName, field.NewPath("metadata"))

	specPath := field.NewPath("spec")
	isHeadlessService := service.Spec.ClusterIP == api.ClusterIPNone
	if len(service.Spec.Ports) == 0 && !isHeadlessService && service.Spec.Type != api.ServiceTypeExternalName {
		allErrs = append(allErrs, field.Required(specPath.Child("ports"), ""))
	}
	switch service.Spec.Type {
	case api.ServiceTypeLoadBalancer:
		for ix := range service.Spec.Ports {
			port := &service.Spec.Ports[ix]
			// This is a workaround for broken cloud environments that
			// over-open firewalls.  Hopefully it can go away when more clouds
			// understand containers better.
			if port.Port == 10250 {
				portPath := specPath.Child("ports").Index(ix)
				allErrs = append(allErrs, field.Invalid(portPath, port.Port, "may not expose port 10250 externally since it is used by kubelet"))
			}
		}
		if service.Spec.ClusterIP == "None" {
			allErrs = append(allErrs, field.Invalid(specPath.Child("clusterIP"), service.Spec.ClusterIP, "may not be set to 'None' for LoadBalancer services"))
		}
	case api.ServiceTypeNodePort:
		if service.Spec.ClusterIP == "None" {
			allErrs = append(allErrs, field.Invalid(specPath.Child("clusterIP"), service.Spec.ClusterIP, "may not be set to 'None' for NodePort services"))
		}
	case api.ServiceTypeExternalName:
		if service.Spec.ClusterIP != "" {
			allErrs = append(allErrs, field.Invalid(specPath.Child("clusterIP"), service.Spec.ClusterIP, "must be empty for ExternalName services"))
		}
		if len(service.Spec.ExternalName) > 0 {
			allErrs = append(allErrs, ValidateDNS1123Subdomain(service.Spec.ExternalName, specPath.Child("externalName"))...)
		} else {
			allErrs = append(allErrs, field.Required(specPath.Child("externalName"), ""))
		}
	}

	allPortNames := sets.String{}
	portsPath := specPath.Child("ports")
	for i := range service.Spec.Ports {
		portPath := portsPath.Index(i)
		allErrs = append(allErrs, validateServicePort(&service.Spec.Ports[i], len(service.Spec.Ports) > 1, isHeadlessService, &allPortNames, portPath)...)
	}

	if service.Spec.Selector != nil {
		allErrs = append(allErrs, unversionedvalidation.ValidateLabels(service.Spec.Selector, specPath.Child("selector"))...)
	}

	if len(service.Spec.SessionAffinity) == 0 {
		allErrs = append(allErrs, field.Required(specPath.Child("sessionAffinity"), ""))
	} else if !supportedSessionAffinityType.Has(string(service.Spec.SessionAffinity)) {
		allErrs = append(allErrs, field.NotSupported(specPath.Child("sessionAffinity"), service.Spec.SessionAffinity, supportedSessionAffinityType.List()))
	}

	if service.Spec.SessionAffinity == api.ServiceAffinityClientIP {
		allErrs = append(allErrs, validateClientIPAffinityConfig(service.Spec.SessionAffinityConfig, specPath.Child("sessionAffinityConfig"))...)
	} else if service.Spec.SessionAffinity == api.ServiceAffinityNone {
		if service.Spec.SessionAffinityConfig != nil {
			allErrs = append(allErrs, field.Forbidden(specPath.Child("sessionAffinityConfig"), fmt.Sprintf("must not be set when session affinity is %s", string(api.ServiceAffinityNone))))
		}
	}

	if helper.IsServiceIPSet(service) {
		if ip := net.ParseIP(service.Spec.ClusterIP); ip == nil {
			allErrs = append(allErrs, field.Invalid(specPath.Child("clusterIP"), service.Spec.ClusterIP, "must be empty, 'None', or a valid IP address"))
		}
	}

	ipPath := specPath.Child("externalIPs")
	for i, ip := range service.Spec.ExternalIPs {
		idxPath := ipPath.Index(i)
		if msgs := validation.IsValidIP(ip); len(msgs) != 0 {
			for i := range msgs {
				allErrs = append(allErrs, field.Invalid(idxPath, ip, msgs[i]))
			}
		} else {
			allErrs = append(allErrs, validateNonSpecialIP(ip, idxPath)...)
		}
	}

	if len(service.Spec.Type) == 0 {
		allErrs = append(allErrs, field.Required(specPath.Child("type"), ""))
	} else if !supportedServiceType.Has(string(service.Spec.Type)) {
		allErrs = append(allErrs, field.NotSupported(specPath.Child("type"), service.Spec.Type, supportedServiceType.List()))
	}

	if service.Spec.Type == api.ServiceTypeLoadBalancer {
		portsPath := specPath.Child("ports")
		includeProtocols := sets.NewString()
		for i := range service.Spec.Ports {
			portPath := portsPath.Index(i)
			if !supportedPortProtocols.Has(string(service.Spec.Ports[i].Protocol)) {
				allErrs = append(allErrs, field.Invalid(portPath.Child("protocol"), service.Spec.Ports[i].Protocol, "cannot create an external load balancer with non-TCP/UDP ports"))
			} else {
				includeProtocols.Insert(string(service.Spec.Ports[i].Protocol))
			}
		}
		if includeProtocols.Len() > 1 {
			allErrs = append(allErrs, field.Invalid(portsPath, service.Spec.Ports, "cannot create an external load balancer with mix protocols"))
		}
	}

	if service.Spec.Type == api.ServiceTypeClusterIP {
		portsPath := specPath.Child("ports")
		for i := range service.Spec.Ports {
			portPath := portsPath.Index(i)
			if service.Spec.Ports[i].NodePort != 0 {
				allErrs = append(allErrs, field.Invalid(portPath.Child("nodePort"), service.Spec.Ports[i].NodePort, "may not be used when `type` is 'ClusterIP'"))
			}
		}
	}

	// Check for duplicate NodePorts, considering (protocol,port) pairs
	portsPath = specPath.Child("ports")
	nodePorts := make(map[api.ServicePort]bool)
	for i := range service.Spec.Ports {
		port := &service.Spec.Ports[i]
		if port.NodePort == 0 {
			continue
		}
		portPath := portsPath.Index(i)
		var key api.ServicePort
		key.Protocol = port.Protocol
		key.NodePort = port.NodePort
		_, found := nodePorts[key]
		if found {
			allErrs = append(allErrs, field.Duplicate(portPath.Child("nodePort"), port.NodePort))
		}
		nodePorts[key] = true
	}

	// Check for duplicate Ports, considering (protocol,port) pairs
	portsPath = specPath.Child("ports")
	ports := make(map[api.ServicePort]bool)
	for i, port := range service.Spec.Ports {
		portPath := portsPath.Index(i)
		key := api.ServicePort{Protocol: port.Protocol, Port: port.Port}
		_, found := ports[key]
		if found {
			allErrs = append(allErrs, field.Duplicate(portPath, key))
		}
		ports[key] = true
	}

	// Validate SourceRange field and annotation
	_, ok := service.Annotations[api.AnnotationLoadBalancerSourceRangesKey]
	if len(service.Spec.LoadBalancerSourceRanges) > 0 || ok {
		var fieldPath *field.Path
		var val string
		if len(service.Spec.LoadBalancerSourceRanges) > 0 {
			fieldPath = specPath.Child("LoadBalancerSourceRanges")
			val = fmt.Sprintf("%v", service.Spec.LoadBalancerSourceRanges)
		} else {
			fieldPath = field.NewPath("metadata", "annotations").Key(api.AnnotationLoadBalancerSourceRangesKey)
			val = service.Annotations[api.AnnotationLoadBalancerSourceRangesKey]
		}
		if service.Spec.Type != api.ServiceTypeLoadBalancer {
			allErrs = append(allErrs, field.Invalid(fieldPath, "", "may only be used when `type` is 'LoadBalancer'"))
		}
		_, err := apiservice.GetLoadBalancerSourceRanges(service)
		if err != nil {
			allErrs = append(allErrs, field.Invalid(fieldPath, val, "must be a list of IP ranges. For example, 10.240.0.0/24,10.250.0.0/24 "))
		}
	}

	allErrs = append(allErrs, validateServiceExternalTrafficFieldsValue(service)...)

	return allErrs
}

func validateServicePort(sp *api.ServicePort, requireName, isHeadlessService bool, allNames *sets.String, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if requireName && len(sp.Name) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
	} else if len(sp.Name) != 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(sp.Name, fldPath.Child("name"))...)
		if allNames.Has(sp.Name) {
			allErrs = append(allErrs, field.Duplicate(fldPath.Child("name"), sp.Name))
		} else {
			allNames.Insert(sp.Name)
		}
	}

	for _, msg := range validation.IsValidPortNum(int(sp.Port)) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("port"), sp.Port, msg))
	}

	if len(sp.Protocol) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("protocol"), ""))
	} else if !supportedPortProtocols.Has(string(sp.Protocol)) {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("protocol"), sp.Protocol, supportedPortProtocols.List()))
	}

	allErrs = append(allErrs, ValidatePortNumOrName(sp.TargetPort, fldPath.Child("targetPort"))...)

	// in the v1 API, targetPorts on headless services were tolerated.
	// once we have version-specific validation, we can reject this on newer API versions, but until then, we have to tolerate it for compatibility.
	//
	// if isHeadlessService {
	// 	if sp.TargetPort.Type == intstr.String || (sp.TargetPort.Type == intstr.Int && sp.Port != sp.TargetPort.IntValue()) {
	// 		allErrs = append(allErrs, field.Invalid(fldPath.Child("targetPort"), sp.TargetPort, "must be equal to the value of 'port' when clusterIP = None"))
	// 	}
	// }

	return allErrs
}

// validateServiceExternalTrafficFieldsValue validates ExternalTraffic related annotations
// have legal value.
func validateServiceExternalTrafficFieldsValue(service *api.Service) field.ErrorList {
	allErrs := field.ErrorList{}

	// Check first class fields.
	if service.Spec.ExternalTrafficPolicy != "" &&
		service.Spec.ExternalTrafficPolicy != api.ServiceExternalTrafficPolicyTypeCluster &&
		service.Spec.ExternalTrafficPolicy != api.ServiceExternalTrafficPolicyTypeLocal {
		allErrs = append(allErrs, field.Invalid(field.NewPath("spec").Child("externalTrafficPolicy"), service.Spec.ExternalTrafficPolicy,
			fmt.Sprintf("ExternalTrafficPolicy must be empty, %v or %v", api.ServiceExternalTrafficPolicyTypeCluster, api.ServiceExternalTrafficPolicyTypeLocal)))
	}
	if service.Spec.HealthCheckNodePort < 0 {
		allErrs = append(allErrs, field.Invalid(field.NewPath("spec").Child("healthCheckNodePort"), service.Spec.HealthCheckNodePort,
			"HealthCheckNodePort must be not less than 0"))
	}

	return allErrs
}

// ValidateServiceExternalTrafficFieldsCombination validates if ExternalTrafficPolicy,
// HealthCheckNodePort and Type combination are legal. For update, it should be called
// after clearing externalTraffic related fields for the ease of transitioning between
// different service types.
func ValidateServiceExternalTrafficFieldsCombination(service *api.Service) field.ErrorList {
	allErrs := field.ErrorList{}

	if service.Spec.Type != api.ServiceTypeLoadBalancer &&
		service.Spec.Type != api.ServiceTypeNodePort &&
		service.Spec.ExternalTrafficPolicy != "" {
		allErrs = append(allErrs, field.Invalid(field.NewPath("spec", "externalTrafficPolicy"), service.Spec.ExternalTrafficPolicy,
			"ExternalTrafficPolicy can only be set on NodePort and LoadBalancer service"))
	}

	if !apiservice.NeedsHealthCheck(service) &&
		service.Spec.HealthCheckNodePort != 0 {
		allErrs = append(allErrs, field.Invalid(field.NewPath("spec", "healthCheckNodePort"), service.Spec.HealthCheckNodePort,
			"HealthCheckNodePort can only be set on LoadBalancer service with ExternalTrafficPolicy=Local"))
	}

	return allErrs
}

// ValidateServiceUpdate tests if required fields in the service are set during an update
func ValidateServiceUpdate(service, oldService *api.Service) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&service.ObjectMeta, &oldService.ObjectMeta, field.NewPath("metadata"))

	// ClusterIP should be immutable for services using it (every type other than ExternalName)
	// which do not have ClusterIP assigned yet (empty string value)
	if service.Spec.Type != api.ServiceTypeExternalName {
		if oldService.Spec.Type != api.ServiceTypeExternalName && oldService.Spec.ClusterIP != "" {
			allErrs = append(allErrs, ValidateImmutableField(service.Spec.ClusterIP, oldService.Spec.ClusterIP, field.NewPath("spec", "clusterIP"))...)
		}
	}

	allErrs = append(allErrs, ValidateService(service)...)
	return allErrs
}

// ValidateServiceStatusUpdate tests if required fields in the Service are set when updating status.
func ValidateServiceStatusUpdate(service, oldService *api.Service) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&service.ObjectMeta, &oldService.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateLoadBalancerStatus(&service.Status.LoadBalancer, field.NewPath("status", "loadBalancer"))...)
	return allErrs
}

// ValidateReplicationController tests if required fields in the replication controller are set.
func ValidateReplicationController(controller *api.ReplicationController) field.ErrorList {
	allErrs := ValidateObjectMeta(&controller.ObjectMeta, true, ValidateReplicationControllerName, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateReplicationControllerSpec(&controller.Spec, field.NewPath("spec"))...)
	return allErrs
}

// ValidateReplicationControllerUpdate tests if required fields in the replication controller are set.
func ValidateReplicationControllerUpdate(controller, oldController *api.ReplicationController) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&controller.ObjectMeta, &oldController.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateReplicationControllerSpec(&controller.Spec, field.NewPath("spec"))...)
	return allErrs
}

// ValidateReplicationControllerStatusUpdate tests if required fields in the replication controller are set.
func ValidateReplicationControllerStatusUpdate(controller, oldController *api.ReplicationController) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&controller.ObjectMeta, &oldController.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateReplicationControllerStatus(controller.Status, field.NewPath("status"))...)
	return allErrs
}

func ValidateReplicationControllerStatus(status api.ReplicationControllerStatus, statusPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, ValidateNonnegativeField(int64(status.Replicas), statusPath.Child("replicas"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(status.FullyLabeledReplicas), statusPath.Child("fullyLabeledReplicas"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(status.ReadyReplicas), statusPath.Child("readyReplicas"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(status.AvailableReplicas), statusPath.Child("availableReplicas"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(status.ObservedGeneration), statusPath.Child("observedGeneration"))...)
	msg := "cannot be greater than status.replicas"
	if status.FullyLabeledReplicas > status.Replicas {
		allErrs = append(allErrs, field.Invalid(statusPath.Child("fullyLabeledReplicas"), status.FullyLabeledReplicas, msg))
	}
	if status.ReadyReplicas > status.Replicas {
		allErrs = append(allErrs, field.Invalid(statusPath.Child("readyReplicas"), status.ReadyReplicas, msg))
	}
	if status.AvailableReplicas > status.Replicas {
		allErrs = append(allErrs, field.Invalid(statusPath.Child("availableReplicas"), status.AvailableReplicas, msg))
	}
	if status.AvailableReplicas > status.ReadyReplicas {
		allErrs = append(allErrs, field.Invalid(statusPath.Child("availableReplicas"), status.AvailableReplicas, "cannot be greater than readyReplicas"))
	}
	return allErrs
}

// Validates that the given selector is non-empty.
func ValidateNonEmptySelector(selectorMap map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	selector := labels.Set(selectorMap).AsSelector()
	if selector.Empty() {
		allErrs = append(allErrs, field.Required(fldPath, ""))
	}
	return allErrs
}

// Validates the given template and ensures that it is in accordance with the desired selector and replicas.
func ValidatePodTemplateSpecForRC(template *api.PodTemplateSpec, selectorMap map[string]string, replicas int32, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if template == nil {
		allErrs = append(allErrs, field.Required(fldPath, ""))
	} else {
		selector := labels.Set(selectorMap).AsSelector()
		if !selector.Empty() {
			// Verify that the RC selector matches the labels in template.
			labels := labels.Set(template.Labels)
			if !selector.Matches(labels) {
				allErrs = append(allErrs, field.Invalid(fldPath.Child("metadata", "labels"), template.Labels, "`selector` does not match template `labels`"))
			}
		}
		allErrs = append(allErrs, ValidatePodTemplateSpec(template, fldPath)...)
		if replicas > 1 {
			allErrs = append(allErrs, ValidateReadOnlyPersistentDisks(template.Spec.Volumes, fldPath.Child("spec", "volumes"))...)
		}
		// RestartPolicy has already been first-order validated as per ValidatePodTemplateSpec().
		if template.Spec.RestartPolicy != api.RestartPolicyAlways {
			allErrs = append(allErrs, field.NotSupported(fldPath.Child("spec", "restartPolicy"), template.Spec.RestartPolicy, []string{string(api.RestartPolicyAlways)}))
		}
		if template.Spec.ActiveDeadlineSeconds != nil {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("spec", "activeDeadlineSeconds"), template.Spec.ActiveDeadlineSeconds, "must not be specified"))
		}
	}
	return allErrs
}

// ValidateReplicationControllerSpec tests if required fields in the replication controller spec are set.
func ValidateReplicationControllerSpec(spec *api.ReplicationControllerSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, ValidateNonnegativeField(int64(spec.MinReadySeconds), fldPath.Child("minReadySeconds"))...)
	allErrs = append(allErrs, ValidateNonEmptySelector(spec.Selector, fldPath.Child("selector"))...)
	allErrs = append(allErrs, ValidateNonnegativeField(int64(spec.Replicas), fldPath.Child("replicas"))...)
	allErrs = append(allErrs, ValidatePodTemplateSpecForRC(spec.Template, spec.Selector, spec.Replicas, fldPath.Child("template"))...)
	return allErrs
}

// ValidatePodTemplateSpec validates the spec of a pod template
func ValidatePodTemplateSpec(spec *api.PodTemplateSpec, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, unversionedvalidation.ValidateLabels(spec.Labels, fldPath.Child("labels"))...)
	allErrs = append(allErrs, ValidateAnnotations(spec.Annotations, fldPath.Child("annotations"))...)
	allErrs = append(allErrs, ValidatePodSpecificAnnotations(spec.Annotations, &spec.Spec, fldPath.Child("annotations"))...)
	allErrs = append(allErrs, ValidatePodSpec(&spec.Spec, fldPath.Child("spec"))...)
	return allErrs
}

func ValidateReadOnlyPersistentDisks(volumes []api.Volume, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for i := range volumes {
		vol := &volumes[i]
		idxPath := fldPath.Index(i)
		if vol.GCEPersistentDisk != nil {
			if vol.GCEPersistentDisk.ReadOnly == false {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("gcePersistentDisk", "readOnly"), false, "must be true for replicated pods > 1; GCE PD can only be mounted on multiple machines if it is read-only"))
			}
		}
		// TODO: What to do for AWS?  It doesn't support replicas
	}
	return allErrs
}

// ValidateTaintsInNodeAnnotations tests that the serialized taints in Node.Annotations has valid data
func ValidateTaintsInNodeAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	taints, err := helper.GetTaintsFromNodeAnnotations(annotations)
	if err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath, api.TaintsAnnotationKey, err.Error()))
		return allErrs
	}

	if len(taints) > 0 {
		allErrs = append(allErrs, validateNodeTaints(taints, fldPath.Child(api.TaintsAnnotationKey))...)
	}

	return allErrs
}

// validateNodeTaints tests if given taints have valid data.
func validateNodeTaints(taints []api.Taint, fldPath *field.Path) field.ErrorList {
	allErrors := field.ErrorList{}

	uniqueTaints := map[api.TaintEffect]sets.String{}

	for i, currTaint := range taints {
		idxPath := fldPath.Index(i)
		// validate the taint key
		allErrors = append(allErrors, unversionedvalidation.ValidateLabelName(currTaint.Key, idxPath.Child("key"))...)
		// validate the taint value
		if errs := validation.IsValidLabelValue(currTaint.Value); len(errs) != 0 {
			allErrors = append(allErrors, field.Invalid(idxPath.Child("value"), currTaint.Value, strings.Join(errs, ";")))
		}
		// validate the taint effect
		allErrors = append(allErrors, validateTaintEffect(&currTaint.Effect, false, idxPath.Child("effect"))...)

		// validate if taint is unique by <key, effect>
		if len(uniqueTaints[currTaint.Effect]) > 0 && uniqueTaints[currTaint.Effect].Has(currTaint.Key) {
			duplicatedError := field.Duplicate(idxPath, currTaint)
			duplicatedError.Detail = "taints must be unique by key and effect pair"
			allErrors = append(allErrors, duplicatedError)
			continue
		}

		// add taint to existingTaints for uniqueness check
		if len(uniqueTaints[currTaint.Effect]) == 0 {
			uniqueTaints[currTaint.Effect] = sets.String{}
		}
		uniqueTaints[currTaint.Effect].Insert(currTaint.Key)
	}
	return allErrors
}

func ValidateNodeSpecificAnnotations(annotations map[string]string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	if annotations[api.TaintsAnnotationKey] != "" {
		allErrs = append(allErrs, ValidateTaintsInNodeAnnotations(annotations, fldPath)...)
	}

	if annotations[api.PreferAvoidPodsAnnotationKey] != "" {
		allErrs = append(allErrs, ValidateAvoidPodsInNodeAnnotations(annotations, fldPath)...)
	}
	return allErrs
}

// ValidateNode tests if required fields in the node are set.
func ValidateNode(node *api.Node) field.ErrorList {
	fldPath := field.NewPath("metadata")
	allErrs := ValidateObjectMeta(&node.ObjectMeta, false, ValidateNodeName, fldPath)
	allErrs = append(allErrs, ValidateNodeSpecificAnnotations(node.ObjectMeta.Annotations, fldPath.Child("annotations"))...)
	if len(node.Spec.Taints) > 0 {
		allErrs = append(allErrs, validateNodeTaints(node.Spec.Taints, fldPath.Child("taints"))...)
	}

	// Only validate spec.
	// All status fields are optional and can be updated later.
	// That said, if specified, we need to ensure they are valid.
	allErrs = append(allErrs, ValidateNodeResources(node)...)

	// external ID is required.
	if len(node.Spec.ExternalID) == 0 {
		allErrs = append(allErrs, field.Required(field.NewPath("spec", "externalID"), ""))
	}

	// Only allow Node.Spec.ConfigSource to be set if the DynamicKubeletConfig feature gate is enabled
	if node.Spec.ConfigSource != nil && !utilfeature.DefaultFeatureGate.Enabled(features.DynamicKubeletConfig) {
		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec", "configSource"), "configSource may only be set if the DynamicKubeletConfig feature gate is enabled)"))
	}

	// TODO(rjnagal): Ignore PodCIDR till its completely implemented.
	return allErrs
}

// ValidateNodeResources is used to make sure a node has valid capacity and allocatable values.
func ValidateNodeResources(node *api.Node) field.ErrorList {
	allErrs := field.ErrorList{}
	// Validate resource quantities in capacity.
	hugePageSizes := sets.NewString()
	for k, v := range node.Status.Capacity {
		resPath := field.NewPath("status", "capacity", string(k))
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
		// track any huge page size that has a positive value
		if helper.IsHugePageResourceName(k) && v.Value() > int64(0) {
			hugePageSizes.Insert(string(k))
		}
		if len(hugePageSizes) > 1 {
			allErrs = append(allErrs, field.Invalid(resPath, v, "may not have pre-allocated hugepages for multiple page sizes"))
		}
	}
	// Validate resource quantities in allocatable.
	hugePageSizes = sets.NewString()
	for k, v := range node.Status.Allocatable {
		resPath := field.NewPath("status", "allocatable", string(k))
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
		// track any huge page size that has a positive value
		if helper.IsHugePageResourceName(k) && v.Value() > int64(0) {
			hugePageSizes.Insert(string(k))
		}
		if len(hugePageSizes) > 1 {
			allErrs = append(allErrs, field.Invalid(resPath, v, "may not have pre-allocated hugepages for multiple page sizes"))
		}
	}
	return allErrs
}

// ValidateNodeUpdate tests to make sure a node update can be applied.  Modifies oldNode.
func ValidateNodeUpdate(node, oldNode *api.Node) field.ErrorList {
	fldPath := field.NewPath("metadata")
	allErrs := ValidateObjectMetaUpdate(&node.ObjectMeta, &oldNode.ObjectMeta, fldPath)
	allErrs = append(allErrs, ValidateNodeSpecificAnnotations(node.ObjectMeta.Annotations, fldPath.Child("annotations"))...)

	// TODO: Enable the code once we have better api object.status update model. Currently,
	// anyone can update node status.
	// if !apiequality.Semantic.DeepEqual(node.Status, api.NodeStatus{}) {
	// 	allErrs = append(allErrs, field.Invalid("status", node.Status, "must be empty"))
	// }

	allErrs = append(allErrs, ValidateNodeResources(node)...)

	// Validate no duplicate addresses in node status.
	addresses := make(map[api.NodeAddress]bool)
	for i, address := range node.Status.Addresses {
		if _, ok := addresses[address]; ok {
			allErrs = append(allErrs, field.Duplicate(field.NewPath("status", "addresses").Index(i), address))
		}
		addresses[address] = true
	}

	if len(oldNode.Spec.PodCIDR) == 0 {
		// Allow the controller manager to assign a CIDR to a node if it doesn't have one.
		oldNode.Spec.PodCIDR = node.Spec.PodCIDR
	} else {
		if oldNode.Spec.PodCIDR != node.Spec.PodCIDR {
			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec", "podCIDR"), "node updates may not change podCIDR except from \"\" to valid"))
		}
	}

	// Allow controller manager updating provider ID when not set
	if len(oldNode.Spec.ProviderID) == 0 {
		oldNode.Spec.ProviderID = node.Spec.ProviderID
	} else {
		if oldNode.Spec.ProviderID != node.Spec.ProviderID {
			allErrs = append(allErrs, field.Forbidden(field.NewPath("spec", "providerID"), "node updates may not change providerID except from \"\" to valid"))
		}
	}

	// TODO: move reset function to its own location
	// Ignore metadata changes now that they have been tested
	oldNode.ObjectMeta = node.ObjectMeta
	// Allow users to update capacity
	oldNode.Status.Capacity = node.Status.Capacity
	// Allow users to unschedule node
	oldNode.Spec.Unschedulable = node.Spec.Unschedulable
	// Clear status
	oldNode.Status = node.Status

	// update taints
	if len(node.Spec.Taints) > 0 {
		allErrs = append(allErrs, validateNodeTaints(node.Spec.Taints, fldPath.Child("taints"))...)
	}
	oldNode.Spec.Taints = node.Spec.Taints

	// Allow updates to Node.Spec.ConfigSource if DynamicKubeletConfig feature gate is enabled
	if utilfeature.DefaultFeatureGate.Enabled(features.DynamicKubeletConfig) {
		oldNode.Spec.ConfigSource = node.Spec.ConfigSource
	}

	// We made allowed changes to oldNode, and now we compare oldNode to node. Any remaining differences indicate changes to protected fields.
	// TODO: Add a 'real' error type for this error and provide print actual diffs.
	if !apiequality.Semantic.DeepEqual(oldNode, node) {
		glog.V(4).Infof("Update failed validation %#v vs %#v", oldNode, node)
		allErrs = append(allErrs, field.Forbidden(field.NewPath(""), "node updates may only change labels, taints, or capacity (or configSource, if the DynamicKubeletConfig feature gate is enabled)"))
	}

	return allErrs
}

// Validate compute resource typename.
// Refer to docs/design/resources.md for more details.
func validateResourceName(value string, fldPath *field.Path) field.ErrorList {
	// Opaque integer resources (OIR) deprecation began in v1.8
	// TODO: Remove warning after OIR deprecation cycle.
	if helper.IsOpaqueIntResourceName(api.ResourceName(value)) {
		glog.Errorf("DEPRECATION WARNING! Opaque integer resources are deprecated starting with v1.8: %s", value)
	}

	allErrs := field.ErrorList{}
	for _, msg := range validation.IsQualifiedName(value) {
		allErrs = append(allErrs, field.Invalid(fldPath, value, msg))
	}
	if len(allErrs) != 0 {
		return allErrs
	}

	if len(strings.Split(value, "/")) == 1 {
		if !helper.IsStandardResourceName(value) {
			return append(allErrs, field.Invalid(fldPath, value, "must be a standard resource type or fully qualified"))
		}
	}

	return allErrs
}

// Validate container resource name
// Refer to docs/design/resources.md for more details.
func validateContainerResourceName(value string, fldPath *field.Path) field.ErrorList {
	allErrs := validateResourceName(value, fldPath)

	if len(strings.Split(value, "/")) == 1 {
		if !helper.IsStandardContainerResourceName(value) {
			return append(allErrs, field.Invalid(fldPath, value, "must be a standard resource for containers"))
		}
	}
	return allErrs
}

// isLocalStorageResource checks whether the resource is local ephemeral storage
func isLocalStorageResource(name string) bool {
	if name == string(api.ResourceEphemeralStorage) || name == string(api.ResourceRequestsEphemeralStorage) ||
		name == string(api.ResourceLimitsEphemeralStorage) {
		return true
	} else {
		return false
	}
}

// Validate resource names that can go in a resource quota
// Refer to docs/design/resources.md for more details.
func ValidateResourceQuotaResourceName(value string, fldPath *field.Path) field.ErrorList {
	allErrs := validateResourceName(value, fldPath)
	if isLocalStorageResource(value) && !utilfeature.DefaultFeatureGate.Enabled(features.LocalStorageCapacityIsolation) {
		return append(allErrs, field.Forbidden(fldPath, "ResourceEphemeralStorage field disabled by feature-gate for ResourceQuota"))
	}
	if len(strings.Split(value, "/")) == 1 {
		if !helper.IsStandardQuotaResourceName(value) {
			return append(allErrs, field.Invalid(fldPath, value, isInvalidQuotaResource))
		}
	}
	return allErrs
}

// Validate limit range types
func validateLimitRangeTypeName(value string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for _, msg := range validation.IsQualifiedName(value) {
		allErrs = append(allErrs, field.Invalid(fldPath, value, msg))
	}
	if len(allErrs) != 0 {
		return allErrs
	}

	if len(strings.Split(value, "/")) == 1 {
		if !helper.IsStandardLimitRangeType(value) {
			return append(allErrs, field.Invalid(fldPath, value, "must be a standard limit type or fully qualified"))
		}
	}

	return allErrs
}

// Validate limit range resource name
// limit types (other than Pod/Container) could contain storage not just cpu or memory
func validateLimitRangeResourceName(limitType api.LimitType, value string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if value == string(api.ResourceEphemeralStorage) && !utilfeature.DefaultFeatureGate.Enabled(features.LocalStorageCapacityIsolation) {
		return append(allErrs, field.Forbidden(fldPath, "ResourceEphemeralStorage field disabled by feature-gate for Resource LimitRange"))
	}
	switch limitType {
	case api.LimitTypePod, api.LimitTypeContainer:
		return validateContainerResourceName(value, fldPath)
	default:
		return validateResourceName(value, fldPath)
	}
}

// ValidateLimitRange tests if required fields in the LimitRange are set.
func ValidateLimitRange(limitRange *api.LimitRange) field.ErrorList {
	allErrs := ValidateObjectMeta(&limitRange.ObjectMeta, true, ValidateLimitRangeName, field.NewPath("metadata"))

	// ensure resource names are properly qualified per docs/design/resources.md
	limitTypeSet := map[api.LimitType]bool{}
	fldPath := field.NewPath("spec", "limits")
	for i := range limitRange.Spec.Limits {
		idxPath := fldPath.Index(i)
		limit := &limitRange.Spec.Limits[i]
		allErrs = append(allErrs, validateLimitRangeTypeName(string(limit.Type), idxPath.Child("type"))...)

		_, found := limitTypeSet[limit.Type]
		if found {
			allErrs = append(allErrs, field.Duplicate(idxPath.Child("type"), limit.Type))
		}
		limitTypeSet[limit.Type] = true

		keys := sets.String{}
		min := map[string]resource.Quantity{}
		max := map[string]resource.Quantity{}
		defaults := map[string]resource.Quantity{}
		defaultRequests := map[string]resource.Quantity{}
		maxLimitRequestRatios := map[string]resource.Quantity{}

		for k, q := range limit.Max {
			allErrs = append(allErrs, validateLimitRangeResourceName(limit.Type, string(k), idxPath.Child("max").Key(string(k)))...)
			keys.Insert(string(k))
			max[string(k)] = q
		}
		for k, q := range limit.Min {
			allErrs = append(allErrs, validateLimitRangeResourceName(limit.Type, string(k), idxPath.Child("min").Key(string(k)))...)
			keys.Insert(string(k))
			min[string(k)] = q
		}

		if limit.Type == api.LimitTypePod {
			if len(limit.Default) > 0 {
				allErrs = append(allErrs, field.Forbidden(idxPath.Child("default"), "may not be specified when `type` is 'Pod'"))
			}
			if len(limit.DefaultRequest) > 0 {
				allErrs = append(allErrs, field.Forbidden(idxPath.Child("defaultRequest"), "may not be specified when `type` is 'Pod'"))
			}
		} else {
			for k, q := range limit.Default {
				allErrs = append(allErrs, validateLimitRangeResourceName(limit.Type, string(k), idxPath.Child("default").Key(string(k)))...)
				keys.Insert(string(k))
				defaults[string(k)] = q
			}
			for k, q := range limit.DefaultRequest {
				allErrs = append(allErrs, validateLimitRangeResourceName(limit.Type, string(k), idxPath.Child("defaultRequest").Key(string(k)))...)
				keys.Insert(string(k))
				defaultRequests[string(k)] = q
			}
		}

		if limit.Type == api.LimitTypePersistentVolumeClaim {
			_, minQuantityFound := limit.Min[api.ResourceStorage]
			_, maxQuantityFound := limit.Max[api.ResourceStorage]
			if !minQuantityFound && !maxQuantityFound {
				allErrs = append(allErrs, field.Required(idxPath.Child("limits"), "either minimum or maximum storage value is required, but neither was provided"))
			}
		}

		for k, q := range limit.MaxLimitRequestRatio {
			allErrs = append(allErrs, validateLimitRangeResourceName(limit.Type, string(k), idxPath.Child("maxLimitRequestRatio").Key(string(k)))...)
			keys.Insert(string(k))
			maxLimitRequestRatios[string(k)] = q
		}

		for k := range keys {
			minQuantity, minQuantityFound := min[k]
			maxQuantity, maxQuantityFound := max[k]
			defaultQuantity, defaultQuantityFound := defaults[k]
			defaultRequestQuantity, defaultRequestQuantityFound := defaultRequests[k]
			maxRatio, maxRatioFound := maxLimitRequestRatios[k]

			if minQuantityFound && maxQuantityFound && minQuantity.Cmp(maxQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("min").Key(string(k)), minQuantity, fmt.Sprintf("min value %s is greater than max value %s", minQuantity.String(), maxQuantity.String())))
			}

			if defaultRequestQuantityFound && minQuantityFound && minQuantity.Cmp(defaultRequestQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("defaultRequest").Key(string(k)), defaultRequestQuantity, fmt.Sprintf("min value %s is greater than default request value %s", minQuantity.String(), defaultRequestQuantity.String())))
			}

			if defaultRequestQuantityFound && maxQuantityFound && defaultRequestQuantity.Cmp(maxQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("defaultRequest").Key(string(k)), defaultRequestQuantity, fmt.Sprintf("default request value %s is greater than max value %s", defaultRequestQuantity.String(), maxQuantity.String())))
			}

			if defaultRequestQuantityFound && defaultQuantityFound && defaultRequestQuantity.Cmp(defaultQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("defaultRequest").Key(string(k)), defaultRequestQuantity, fmt.Sprintf("default request value %s is greater than default limit value %s", defaultRequestQuantity.String(), defaultQuantity.String())))
			}

			if defaultQuantityFound && minQuantityFound && minQuantity.Cmp(defaultQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("default").Key(string(k)), minQuantity, fmt.Sprintf("min value %s is greater than default value %s", minQuantity.String(), defaultQuantity.String())))
			}

			if defaultQuantityFound && maxQuantityFound && defaultQuantity.Cmp(maxQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("default").Key(string(k)), maxQuantity, fmt.Sprintf("default value %s is greater than max value %s", defaultQuantity.String(), maxQuantity.String())))
			}
			if maxRatioFound && maxRatio.Cmp(*resource.NewQuantity(1, resource.DecimalSI)) < 0 {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("maxLimitRequestRatio").Key(string(k)), maxRatio, fmt.Sprintf("ratio %s is less than 1", maxRatio.String())))
			}
			if maxRatioFound && minQuantityFound && maxQuantityFound {
				maxRatioValue := float64(maxRatio.Value())
				minQuantityValue := minQuantity.Value()
				maxQuantityValue := maxQuantity.Value()
				if maxRatio.Value() < resource.MaxMilliValue && minQuantityValue < resource.MaxMilliValue && maxQuantityValue < resource.MaxMilliValue {
					maxRatioValue = float64(maxRatio.MilliValue()) / 1000
					minQuantityValue = minQuantity.MilliValue()
					maxQuantityValue = maxQuantity.MilliValue()
				}
				maxRatioLimit := float64(maxQuantityValue) / float64(minQuantityValue)
				if maxRatioValue > maxRatioLimit {
					allErrs = append(allErrs, field.Invalid(idxPath.Child("maxLimitRequestRatio").Key(string(k)), maxRatio, fmt.Sprintf("ratio %s is greater than max/min = %f", maxRatio.String(), maxRatioLimit)))
				}
			}
		}
	}

	return allErrs
}

// ValidateServiceAccount tests if required fields in the ServiceAccount are set.
func ValidateServiceAccount(serviceAccount *api.ServiceAccount) field.ErrorList {
	allErrs := ValidateObjectMeta(&serviceAccount.ObjectMeta, true, ValidateServiceAccountName, field.NewPath("metadata"))
	return allErrs
}

// ValidateServiceAccountUpdate tests if required fields in the ServiceAccount are set.
func ValidateServiceAccountUpdate(newServiceAccount, oldServiceAccount *api.ServiceAccount) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newServiceAccount.ObjectMeta, &oldServiceAccount.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateServiceAccount(newServiceAccount)...)
	return allErrs
}

// ValidateSecret tests if required fields in the Secret are set.
func ValidateSecret(secret *api.Secret) field.ErrorList {
	allErrs := ValidateObjectMeta(&secret.ObjectMeta, true, ValidateSecretName, field.NewPath("metadata"))

	dataPath := field.NewPath("data")
	totalSize := 0
	for key, value := range secret.Data {
		for _, msg := range validation.IsConfigMapKey(key) {
			allErrs = append(allErrs, field.Invalid(dataPath.Key(key), key, msg))
		}
		totalSize += len(value)
	}
	if totalSize > api.MaxSecretSize {
		allErrs = append(allErrs, field.TooLong(dataPath, "", api.MaxSecretSize))
	}

	switch secret.Type {
	case api.SecretTypeServiceAccountToken:
		// Only require Annotations[kubernetes.io/service-account.name]
		// Additional fields (like Annotations[kubernetes.io/service-account.uid] and Data[token]) might be contributed later by a controller loop
		if value := secret.Annotations[api.ServiceAccountNameKey]; len(value) == 0 {
			allErrs = append(allErrs, field.Required(field.NewPath("metadata", "annotations").Key(api.ServiceAccountNameKey), ""))
		}
	case api.SecretTypeOpaque, "":
	// no-op
	case api.SecretTypeDockercfg:
		dockercfgBytes, exists := secret.Data[api.DockerConfigKey]
		if !exists {
			allErrs = append(allErrs, field.Required(dataPath.Key(api.DockerConfigKey), ""))
			break
		}

		// make sure that the content is well-formed json.
		if err := json.Unmarshal(dockercfgBytes, &map[string]interface{}{}); err != nil {
			allErrs = append(allErrs, field.Invalid(dataPath.Key(api.DockerConfigKey), "<secret contents redacted>", err.Error()))
		}
	case api.SecretTypeDockerConfigJson:
		dockerConfigJsonBytes, exists := secret.Data[api.DockerConfigJsonKey]
		if !exists {
			allErrs = append(allErrs, field.Required(dataPath.Key(api.DockerConfigJsonKey), ""))
			break
		}

		// make sure that the content is well-formed json.
		if err := json.Unmarshal(dockerConfigJsonBytes, &map[string]interface{}{}); err != nil {
			allErrs = append(allErrs, field.Invalid(dataPath.Key(api.DockerConfigJsonKey), "<secret contents redacted>", err.Error()))
		}
	case api.SecretTypeBasicAuth:
		_, usernameFieldExists := secret.Data[api.BasicAuthUsernameKey]
		_, passwordFieldExists := secret.Data[api.BasicAuthPasswordKey]

		// username or password might be empty, but the field must be present
		if !usernameFieldExists && !passwordFieldExists {
			allErrs = append(allErrs, field.Required(field.NewPath("data[%s]").Key(api.BasicAuthUsernameKey), ""))
			allErrs = append(allErrs, field.Required(field.NewPath("data[%s]").Key(api.BasicAuthPasswordKey), ""))
			break
		}
	case api.SecretTypeSSHAuth:
		if len(secret.Data[api.SSHAuthPrivateKey]) == 0 {
			allErrs = append(allErrs, field.Required(field.NewPath("data[%s]").Key(api.SSHAuthPrivateKey), ""))
			break
		}

	case api.SecretTypeTLS:
		if _, exists := secret.Data[api.TLSCertKey]; !exists {
			allErrs = append(allErrs, field.Required(dataPath.Key(api.TLSCertKey), ""))
		}
		if _, exists := secret.Data[api.TLSPrivateKeyKey]; !exists {
			allErrs = append(allErrs, field.Required(dataPath.Key(api.TLSPrivateKeyKey), ""))
		}
	// TODO: Verify that the key matches the cert.
	default:
		// no-op
	}

	return allErrs
}

// ValidateSecretUpdate tests if required fields in the Secret are set.
func ValidateSecretUpdate(newSecret, oldSecret *api.Secret) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newSecret.ObjectMeta, &oldSecret.ObjectMeta, field.NewPath("metadata"))

	if len(newSecret.Type) == 0 {
		newSecret.Type = oldSecret.Type
	}

	allErrs = append(allErrs, ValidateImmutableField(newSecret.Type, oldSecret.Type, field.NewPath("type"))...)

	allErrs = append(allErrs, ValidateSecret(newSecret)...)
	return allErrs
}

// ValidateConfigMapName can be used to check whether the given ConfigMap name is valid.
// Prefix indicates this name will be used as part of generation, in which case
// trailing dashes are allowed.
var ValidateConfigMapName = NameIsDNSSubdomain

// ValidateConfigMap tests whether required fields in the ConfigMap are set.
func ValidateConfigMap(cfg *api.ConfigMap) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, ValidateObjectMeta(&cfg.ObjectMeta, true, ValidateConfigMapName, field.NewPath("metadata"))...)

	totalSize := 0

	for key, value := range cfg.Data {
		for _, msg := range validation.IsConfigMapKey(key) {
			allErrs = append(allErrs, field.Invalid(field.NewPath("data").Key(key), key, msg))
		}
		totalSize += len(value)
	}
	if totalSize > api.MaxSecretSize {
		allErrs = append(allErrs, field.TooLong(field.NewPath("data"), "", api.MaxSecretSize))
	}

	return allErrs
}

// ValidateConfigMapUpdate tests if required fields in the ConfigMap are set.
func ValidateConfigMapUpdate(newCfg, oldCfg *api.ConfigMap) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, ValidateObjectMetaUpdate(&newCfg.ObjectMeta, &oldCfg.ObjectMeta, field.NewPath("metadata"))...)
	allErrs = append(allErrs, ValidateConfigMap(newCfg)...)

	return allErrs
}

func validateBasicResource(quantity resource.Quantity, fldPath *field.Path) field.ErrorList {
	if quantity.Value() < 0 {
		return field.ErrorList{field.Invalid(fldPath, quantity.Value(), "must be a valid resource quantity")}
	}
	return field.ErrorList{}
}

// Validates resource requirement spec.
func ValidateResourceRequirements(requirements *api.ResourceRequirements, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	limPath := fldPath.Child("limits")
	reqPath := fldPath.Child("requests")
	for resourceName, quantity := range requirements.Limits {
		fldPath := limPath.Key(string(resourceName))
		// Validate resource name.
		allErrs = append(allErrs, validateContainerResourceName(string(resourceName), fldPath)...)

		// Validate resource quantity.
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(resourceName), quantity, fldPath)...)

		if resourceName == api.ResourceEphemeralStorage && !utilfeature.DefaultFeatureGate.Enabled(features.LocalStorageCapacityIsolation) {
			allErrs = append(allErrs, field.Forbidden(limPath, "ResourceEphemeralStorage field disabled by feature-gate for ResourceRequirements"))
		}
		if helper.IsHugePageResourceName(resourceName) && !utilfeature.DefaultFeatureGate.Enabled(features.HugePages) {
			allErrs = append(allErrs, field.Forbidden(limPath, fmt.Sprintf("%s field disabled by feature-gate for ResourceRequirements", resourceName)))
		}

	}
	for resourceName, quantity := range requirements.Requests {
		fldPath := reqPath.Key(string(resourceName))
		// Validate resource name.
		allErrs = append(allErrs, validateContainerResourceName(string(resourceName), fldPath)...)
		// Validate resource quantity.
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(resourceName), quantity, fldPath)...)

		// Check that request <= limit.
		limitQuantity, exists := requirements.Limits[resourceName]
		if exists {
			// For GPUs, not only requests can't exceed limits, they also can't be lower, i.e. must be equal.
			if quantity.Cmp(limitQuantity) != 0 && !helper.IsOvercommitAllowed(resourceName) {
				allErrs = append(allErrs, field.Invalid(reqPath, quantity.String(), fmt.Sprintf("must be equal to %s limit", api.ResourceNvidiaGPU)))
			} else if quantity.Cmp(limitQuantity) > 0 {
				allErrs = append(allErrs, field.Invalid(reqPath, quantity.String(), fmt.Sprintf("must be less than or equal to %s limit", resourceName)))
			}
		} else if resourceName == api.ResourceNvidiaGPU {
			allErrs = append(allErrs, field.Invalid(reqPath, quantity.String(), fmt.Sprintf("must be equal to %s request", api.ResourceNvidiaGPU)))
		}
	}

	return allErrs
}

// validateResourceQuotaScopes ensures that each enumerated hard resource constraint is valid for set of scopes
func validateResourceQuotaScopes(resourceQuotaSpec *api.ResourceQuotaSpec, fld *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(resourceQuotaSpec.Scopes) == 0 {
		return allErrs
	}
	hardLimits := sets.NewString()
	for k := range resourceQuotaSpec.Hard {
		hardLimits.Insert(string(k))
	}
	fldPath := fld.Child("scopes")
	scopeSet := sets.NewString()
	for _, scope := range resourceQuotaSpec.Scopes {
		if !helper.IsStandardResourceQuotaScope(string(scope)) {
			allErrs = append(allErrs, field.Invalid(fldPath, resourceQuotaSpec.Scopes, "unsupported scope"))
		}
		for _, k := range hardLimits.List() {
			if helper.IsStandardQuotaResourceName(k) && !helper.IsResourceQuotaScopeValidForResource(scope, k) {
				allErrs = append(allErrs, field.Invalid(fldPath, resourceQuotaSpec.Scopes, "unsupported scope applied to resource"))
			}
		}
		scopeSet.Insert(string(scope))
	}
	invalidScopePairs := []sets.String{
		sets.NewString(string(api.ResourceQuotaScopeBestEffort), string(api.ResourceQuotaScopeNotBestEffort)),
		sets.NewString(string(api.ResourceQuotaScopeTerminating), string(api.ResourceQuotaScopeNotTerminating)),
	}
	for _, invalidScopePair := range invalidScopePairs {
		if scopeSet.HasAll(invalidScopePair.List()...) {
			allErrs = append(allErrs, field.Invalid(fldPath, resourceQuotaSpec.Scopes, "conflicting scopes"))
		}
	}
	return allErrs
}

// ValidateResourceQuota tests if required fields in the ResourceQuota are set.
func ValidateResourceQuota(resourceQuota *api.ResourceQuota) field.ErrorList {
	allErrs := ValidateObjectMeta(&resourceQuota.ObjectMeta, true, ValidateResourceQuotaName, field.NewPath("metadata"))

	allErrs = append(allErrs, ValidateResourceQuotaSpec(&resourceQuota.Spec, field.NewPath("spec"))...)
	allErrs = append(allErrs, ValidateResourceQuotaStatus(&resourceQuota.Status, field.NewPath("status"))...)

	return allErrs
}

func ValidateResourceQuotaStatus(status *api.ResourceQuotaStatus, fld *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	fldPath := fld.Child("hard")
	for k, v := range status.Hard {
		resPath := fldPath.Key(string(k))
		allErrs = append(allErrs, ValidateResourceQuotaResourceName(string(k), resPath)...)
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
	}
	fldPath = fld.Child("used")
	for k, v := range status.Used {
		resPath := fldPath.Key(string(k))
		allErrs = append(allErrs, ValidateResourceQuotaResourceName(string(k), resPath)...)
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
	}

	return allErrs
}

func ValidateResourceQuotaSpec(resourceQuotaSpec *api.ResourceQuotaSpec, fld *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}

	fldPath := fld.Child("hard")
	for k, v := range resourceQuotaSpec.Hard {
		resPath := fldPath.Key(string(k))
		allErrs = append(allErrs, ValidateResourceQuotaResourceName(string(k), resPath)...)
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
	}
	allErrs = append(allErrs, validateResourceQuotaScopes(resourceQuotaSpec, fld)...)

	return allErrs
}

// ValidateResourceQuantityValue enforces that specified quantity is valid for specified resource
func ValidateResourceQuantityValue(resource string, value resource.Quantity, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	allErrs = append(allErrs, ValidateNonnegativeQuantity(value, fldPath)...)
	if helper.IsIntegerResourceName(resource) {
		if value.MilliValue()%int64(1000) != int64(0) {
			allErrs = append(allErrs, field.Invalid(fldPath, value, isNotIntegerErrorMsg))
		}
	}
	return allErrs
}

// ValidateResourceQuotaUpdate tests to see if the update is legal for an end user to make.
// newResourceQuota is updated with fields that cannot be changed.
func ValidateResourceQuotaUpdate(newResourceQuota, oldResourceQuota *api.ResourceQuota) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newResourceQuota.ObjectMeta, &oldResourceQuota.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateResourceQuotaSpec(&newResourceQuota.Spec, field.NewPath("spec"))...)

	// ensure scopes cannot change, and that resources are still valid for scope
	fldPath := field.NewPath("spec", "scopes")
	oldScopes := sets.NewString()
	newScopes := sets.NewString()
	for _, scope := range newResourceQuota.Spec.Scopes {
		newScopes.Insert(string(scope))
	}
	for _, scope := range oldResourceQuota.Spec.Scopes {
		oldScopes.Insert(string(scope))
	}
	if !oldScopes.Equal(newScopes) {
		allErrs = append(allErrs, field.Invalid(fldPath, newResourceQuota.Spec.Scopes, fieldImmutableErrorMsg))
	}

	newResourceQuota.Status = oldResourceQuota.Status
	return allErrs
}

// ValidateResourceQuotaStatusUpdate tests to see if the status update is legal for an end user to make.
// newResourceQuota is updated with fields that cannot be changed.
func ValidateResourceQuotaStatusUpdate(newResourceQuota, oldResourceQuota *api.ResourceQuota) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newResourceQuota.ObjectMeta, &oldResourceQuota.ObjectMeta, field.NewPath("metadata"))
	if len(newResourceQuota.ResourceVersion) == 0 {
		allErrs = append(allErrs, field.Required(field.NewPath("resourceVersion"), ""))
	}
	fldPath := field.NewPath("status", "hard")
	for k, v := range newResourceQuota.Status.Hard {
		resPath := fldPath.Key(string(k))
		allErrs = append(allErrs, ValidateResourceQuotaResourceName(string(k), resPath)...)
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
	}
	fldPath = field.NewPath("status", "used")
	for k, v := range newResourceQuota.Status.Used {
		resPath := fldPath.Key(string(k))
		allErrs = append(allErrs, ValidateResourceQuotaResourceName(string(k), resPath)...)
		allErrs = append(allErrs, ValidateResourceQuantityValue(string(k), v, resPath)...)
	}
	newResourceQuota.Spec = oldResourceQuota.Spec
	return allErrs
}

// ValidateNamespace tests if required fields are set.
func ValidateNamespace(namespace *api.Namespace) field.ErrorList {
	allErrs := ValidateObjectMeta(&namespace.ObjectMeta, false, ValidateNamespaceName, field.NewPath("metadata"))
	for i := range namespace.Spec.Finalizers {
		allErrs = append(allErrs, validateFinalizerName(string(namespace.Spec.Finalizers[i]), field.NewPath("spec", "finalizers"))...)
	}
	return allErrs
}

// Validate finalizer names
func validateFinalizerName(stringValue string, fldPath *field.Path) field.ErrorList {
	allErrs := genericvalidation.ValidateFinalizerName(stringValue, fldPath)
	for _, err := range validateKubeFinalizerName(stringValue, fldPath) {
		allErrs = append(allErrs, err)
	}

	return allErrs
}

// validateKubeFinalizerName checks for "standard" names of legacy finalizer
func validateKubeFinalizerName(stringValue string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if len(strings.Split(stringValue, "/")) == 1 {
		if !helper.IsStandardFinalizerName(stringValue) {
			return append(allErrs, field.Invalid(fldPath, stringValue, "name is neither a standard finalizer name nor is it fully qualified"))
		}
	}

	return allErrs
}

// ValidateNamespaceUpdate tests to make sure a namespace update can be applied.
// newNamespace is updated with fields that cannot be changed
func ValidateNamespaceUpdate(newNamespace *api.Namespace, oldNamespace *api.Namespace) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newNamespace.ObjectMeta, &oldNamespace.ObjectMeta, field.NewPath("metadata"))
	newNamespace.Spec.Finalizers = oldNamespace.Spec.Finalizers
	newNamespace.Status = oldNamespace.Status
	return allErrs
}

// ValidateNamespaceStatusUpdate tests to see if the update is legal for an end user to make. newNamespace is updated with fields
// that cannot be changed.
func ValidateNamespaceStatusUpdate(newNamespace, oldNamespace *api.Namespace) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newNamespace.ObjectMeta, &oldNamespace.ObjectMeta, field.NewPath("metadata"))
	newNamespace.Spec = oldNamespace.Spec
	if newNamespace.DeletionTimestamp.IsZero() {
		if newNamespace.Status.Phase != api.NamespaceActive {
			allErrs = append(allErrs, field.Invalid(field.NewPath("status", "Phase"), newNamespace.Status.Phase, "may only be 'Active' if `deletionTimestamp` is empty"))
		}
	} else {
		if newNamespace.Status.Phase != api.NamespaceTerminating {
			allErrs = append(allErrs, field.Invalid(field.NewPath("status", "Phase"), newNamespace.Status.Phase, "may only be 'Terminating' if `deletionTimestamp` is not empty"))
		}
	}
	return allErrs
}

// ValidateNamespaceFinalizeUpdate tests to see if the update is legal for an end user to make.
// newNamespace is updated with fields that cannot be changed.
func ValidateNamespaceFinalizeUpdate(newNamespace, oldNamespace *api.Namespace) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newNamespace.ObjectMeta, &oldNamespace.ObjectMeta, field.NewPath("metadata"))

	fldPath := field.NewPath("spec", "finalizers")
	for i := range newNamespace.Spec.Finalizers {
		idxPath := fldPath.Index(i)
		allErrs = append(allErrs, validateFinalizerName(string(newNamespace.Spec.Finalizers[i]), idxPath)...)
	}
	newNamespace.Status = oldNamespace.Status
	return allErrs
}

// Construct lookup map of old subset IPs to NodeNames.
func updateEpAddrToNodeNameMap(ipToNodeName map[string]string, addresses []api.EndpointAddress) {
	for n := range addresses {
		if addresses[n].NodeName == nil {
			continue
		}
		ipToNodeName[addresses[n].IP] = *addresses[n].NodeName
	}
}

// Build a map across all subsets of IP -> NodeName
func buildEndpointAddressNodeNameMap(subsets []api.EndpointSubset) map[string]string {
	ipToNodeName := make(map[string]string)
	for i := range subsets {
		updateEpAddrToNodeNameMap(ipToNodeName, subsets[i].Addresses)
		updateEpAddrToNodeNameMap(ipToNodeName, subsets[i].NotReadyAddresses)
	}
	return ipToNodeName
}

func validateEpAddrNodeNameTransition(addr *api.EndpointAddress, ipToNodeName map[string]string, fldPath *field.Path) field.ErrorList {
	errList := field.ErrorList{}
	existingNodeName, found := ipToNodeName[addr.IP]
	if !found {
		return errList
	}
	if addr.NodeName == nil || *addr.NodeName == existingNodeName {
		return errList
	}
	// NodeName entry found for this endpoint IP, but user is attempting to change NodeName
	return append(errList, field.Forbidden(fldPath, fmt.Sprintf("Cannot change NodeName for %s to %s", addr.IP, *addr.NodeName)))
}

// ValidateEndpoints tests if required fields are set.
func ValidateEndpoints(endpoints *api.Endpoints) field.ErrorList {
	allErrs := ValidateObjectMeta(&endpoints.ObjectMeta, true, ValidateEndpointsName, field.NewPath("metadata"))
	allErrs = append(allErrs, ValidateEndpointsSpecificAnnotations(endpoints.Annotations, field.NewPath("annotations"))...)
	allErrs = append(allErrs, validateEndpointSubsets(endpoints.Subsets, []api.EndpointSubset{}, field.NewPath("subsets"))...)
	return allErrs
}

func validateEndpointSubsets(subsets []api.EndpointSubset, oldSubsets []api.EndpointSubset, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	ipToNodeName := buildEndpointAddressNodeNameMap(oldSubsets)
	for i := range subsets {
		ss := &subsets[i]
		idxPath := fldPath.Index(i)

		// EndpointSubsets must include endpoint address. For headless service, we allow its endpoints not to have ports.
		if len(ss.Addresses) == 0 && len(ss.NotReadyAddresses) == 0 {
			//TODO: consider adding a RequiredOneOf() error for this and similar cases
			allErrs = append(allErrs, field.Required(idxPath, "must specify `addresses` or `notReadyAddresses`"))
		}
		for addr := range ss.Addresses {
			allErrs = append(allErrs, validateEndpointAddress(&ss.Addresses[addr], idxPath.Child("addresses").Index(addr), ipToNodeName)...)
		}
		for addr := range ss.NotReadyAddresses {
			allErrs = append(allErrs, validateEndpointAddress(&ss.NotReadyAddresses[addr], idxPath.Child("notReadyAddresses").Index(addr), ipToNodeName)...)
		}
		for port := range ss.Ports {
			allErrs = append(allErrs, validateEndpointPort(&ss.Ports[port], len(ss.Ports) > 1, idxPath.Child("ports").Index(port))...)
		}
	}

	return allErrs
}

func validateEndpointAddress(address *api.EndpointAddress, fldPath *field.Path, ipToNodeName map[string]string) field.ErrorList {
	allErrs := field.ErrorList{}
	for _, msg := range validation.IsValidIP(address.IP) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("ip"), address.IP, msg))
	}
	if len(address.Hostname) > 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(address.Hostname, fldPath.Child("hostname"))...)
	}
	// During endpoint update, verify that NodeName is a DNS subdomain and transition rules allow the update
	if address.NodeName != nil {
		for _, msg := range ValidateNodeName(*address.NodeName, false) {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("nodeName"), *address.NodeName, msg))
		}
	}
	allErrs = append(allErrs, validateEpAddrNodeNameTransition(address, ipToNodeName, fldPath.Child("nodeName"))...)
	if len(allErrs) > 0 {
		return allErrs
	}
	allErrs = append(allErrs, validateNonSpecialIP(address.IP, fldPath.Child("ip"))...)
	return allErrs
}

func validateNonSpecialIP(ipAddress string, fldPath *field.Path) field.ErrorList {
	// We disallow some IPs as endpoints or external-ips.  Specifically,
	// unspecified and loopback addresses are nonsensical and link-local
	// addresses tend to be used for node-centric purposes (e.g. metadata
	// service).
	allErrs := field.ErrorList{}
	ip := net.ParseIP(ipAddress)
	if ip == nil {
		allErrs = append(allErrs, field.Invalid(fldPath, ipAddress, "must be a valid IP address"))
		return allErrs
	}
	if ip.IsUnspecified() {
		allErrs = append(allErrs, field.Invalid(fldPath, ipAddress, "may not be unspecified (0.0.0.0)"))
	}
	if ip.IsLoopback() {
		allErrs = append(allErrs, field.Invalid(fldPath, ipAddress, "may not be in the loopback range (127.0.0.0/8)"))
	}
	if ip.IsLinkLocalUnicast() {
		allErrs = append(allErrs, field.Invalid(fldPath, ipAddress, "may not be in the link-local range (169.254.0.0/16)"))
	}
	if ip.IsLinkLocalMulticast() {
		allErrs = append(allErrs, field.Invalid(fldPath, ipAddress, "may not be in the link-local multicast range (224.0.0.0/24)"))
	}
	return allErrs
}

func validateEndpointPort(port *api.EndpointPort, requireName bool, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if requireName && len(port.Name) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
	} else if len(port.Name) != 0 {
		allErrs = append(allErrs, ValidateDNS1123Label(port.Name, fldPath.Child("name"))...)
	}
	for _, msg := range validation.IsValidPortNum(int(port.Port)) {
		allErrs = append(allErrs, field.Invalid(fldPath.Child("port"), port.Port, msg))
	}
	if len(port.Protocol) == 0 {
		allErrs = append(allErrs, field.Required(fldPath.Child("protocol"), ""))
	} else if !supportedPortProtocols.Has(string(port.Protocol)) {
		allErrs = append(allErrs, field.NotSupported(fldPath.Child("protocol"), port.Protocol, supportedPortProtocols.List()))
	}
	return allErrs
}

// ValidateEndpointsUpdate tests to make sure an endpoints update can be applied.
func ValidateEndpointsUpdate(newEndpoints, oldEndpoints *api.Endpoints) field.ErrorList {
	allErrs := ValidateObjectMetaUpdate(&newEndpoints.ObjectMeta, &oldEndpoints.ObjectMeta, field.NewPath("metadata"))
	allErrs = append(allErrs, validateEndpointSubsets(newEndpoints.Subsets, oldEndpoints.Subsets, field.NewPath("subsets"))...)
	allErrs = append(allErrs, ValidateEndpointsSpecificAnnotations(newEndpoints.Annotations, field.NewPath("annotations"))...)
	return allErrs
}

// ValidateSecurityContext ensure the security context contains valid settings
func ValidateSecurityContext(sc *api.SecurityContext, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	//this should only be true for testing since SecurityContext is defaulted by the api
	if sc == nil {
		return allErrs
	}

	if sc.Privileged != nil {
		if *sc.Privileged && !capabilities.Get().AllowPrivileged {
			allErrs = append(allErrs, field.Forbidden(fldPath.Child("privileged"), "disallowed by cluster policy"))
		}
	}

	if sc.RunAsUser != nil {
		if *sc.RunAsUser < 0 {
			allErrs = append(allErrs, field.Invalid(fldPath.Child("runAsUser"), *sc.RunAsUser, isNegativeErrorMsg))
		}
	}

	if sc.AllowPrivilegeEscalation != nil && !*sc.AllowPrivilegeEscalation {
		if sc.Privileged != nil && *sc.Privileged {
			allErrs = append(allErrs, field.Invalid(fldPath, sc, "cannot set `allowPrivilegeEscalation` to false and `privileged` to true"))
		}

		if sc.Capabilities != nil {
			for _, cap := range sc.Capabilities.Add {
				if string(cap) == "CAP_SYS_ADMIN" {
					allErrs = append(allErrs, field.Invalid(fldPath, sc, "cannot set `allowPrivilegeEscalation` to false and `capabilities.Add` CAP_SYS_ADMIN"))
				}
			}
		}
	}

	return allErrs
}

func ValidatePodLogOptions(opts *api.PodLogOptions) field.ErrorList {
	allErrs := field.ErrorList{}
	if opts.TailLines != nil && *opts.TailLines < 0 {
		allErrs = append(allErrs, field.Invalid(field.NewPath("tailLines"), *opts.TailLines, isNegativeErrorMsg))
	}
	if opts.LimitBytes != nil && *opts.LimitBytes < 1 {
		allErrs = append(allErrs, field.Invalid(field.NewPath("limitBytes"), *opts.LimitBytes, "must be greater than 0"))
	}
	switch {
	case opts.SinceSeconds != nil && opts.SinceTime != nil:
		allErrs = append(allErrs, field.Forbidden(field.NewPath(""), "at most one of `sinceTime` or `sinceSeconds` may be specified"))
	case opts.SinceSeconds != nil:
		if *opts.SinceSeconds < 1 {
			allErrs = append(allErrs, field.Invalid(field.NewPath("sinceSeconds"), *opts.SinceSeconds, "must be greater than 0"))
		}
	}
	return allErrs
}

// ValidateLoadBalancerStatus validates required fields on a LoadBalancerStatus
func ValidateLoadBalancerStatus(status *api.LoadBalancerStatus, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	for i, ingress := range status.Ingress {
		idxPath := fldPath.Child("ingress").Index(i)
		if len(ingress.IP) > 0 {
			if isIP := (net.ParseIP(ingress.IP) != nil); !isIP {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("ip"), ingress.IP, "must be a valid IP address"))
			}
		}
		if len(ingress.Hostname) > 0 {
			for _, msg := range validation.IsDNS1123Subdomain(ingress.Hostname) {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("hostname"), ingress.Hostname, msg))
			}
			if isIP := (net.ParseIP(ingress.Hostname) != nil); isIP {
				allErrs = append(allErrs, field.Invalid(idxPath.Child("hostname"), ingress.Hostname, "must be a DNS name, not an IP address"))
			}
		}
	}
	return allErrs
}

func sysctlIntersection(a []api.Sysctl, b []api.Sysctl) []string {
	lookup := make(map[string]struct{}, len(a))
	result := []string{}
	for i := range a {
		lookup[a[i].Name] = struct{}{}
	}
	for i := range b {
		if _, found := lookup[b[i].Name]; found {
			result = append(result, b[i].Name)
		}
	}
	return result
}

// validateStorageNodeAffinityAnnotation tests that the serialized TopologyConstraints in PersistentVolume.Annotations has valid data
func validateStorageNodeAffinityAnnotation(annotations map[string]string, fldPath *field.Path) (bool, field.ErrorList) {
	allErrs := field.ErrorList{}

	na, err := helper.GetStorageNodeAffinityFromAnnotation(annotations)
	if err != nil {
		allErrs = append(allErrs, field.Invalid(fldPath, api.AlphaStorageNodeAffinityAnnotation, err.Error()))
		return false, allErrs
	}
	if na == nil {
		return false, allErrs
	}

	if !utilfeature.DefaultFeatureGate.Enabled(features.PersistentLocalVolumes) {
		allErrs = append(allErrs, field.Forbidden(fldPath, "Storage node affinity is disabled by feature-gate"))
	}

	policySpecified := false
	if na.RequiredDuringSchedulingIgnoredDuringExecution != nil {
		allErrs = append(allErrs, ValidateNodeSelector(na.RequiredDuringSchedulingIgnoredDuringExecution, fldPath.Child("requiredDuringSchedulingIgnoredDuringExecution"))...)
		policySpecified = true
	}

	if len(na.PreferredDuringSchedulingIgnoredDuringExecution) > 0 {
		allErrs = append(allErrs, field.Forbidden(fldPath.Child("preferredDuringSchedulingIgnoredDuringExection"), "Storage node affinity does not support preferredDuringSchedulingIgnoredDuringExecution"))
	}
	return policySpecified, allErrs
}