func TestCheckInvalidErr(t *testing.T) {
	tests := []struct {
		err      error
		expected string
	}{
		{
			errors.NewInvalid("Invalid1", "invalidation", fielderrors.ValidationErrorList{fielderrors.NewFieldInvalid("Cause", "single", "details")}),
			`Error from server: Invalid1 "invalidation" is invalid: Cause: invalid value 'single', Details: details`,
		},
		{
			errors.NewInvalid("Invalid2", "invalidation", fielderrors.ValidationErrorList{fielderrors.NewFieldInvalid("Cause", "multi1", "details"), fielderrors.NewFieldInvalid("Cause", "multi2", "details")}),
			`Error from server: Invalid2 "invalidation" is invalid: [Cause: invalid value 'multi1', Details: details, Cause: invalid value 'multi2', Details: details]`,
		},
		{
			errors.NewInvalid("Invalid3", "invalidation", fielderrors.ValidationErrorList{}),
			`Error from server: Invalid3 "invalidation" is invalid: <nil>`,
		},
	}

	var errReturned string
	errHandle := func(err string) {
		errReturned = err
	}

	for _, test := range tests {
		checkErr(test.err, errHandle)

		if errReturned != test.expected {
			t.Fatalf("Got: %s, expected: %s", errReturned, test.expected)
		}
	}
}

func ValidateJobSpec(spec *extensions.JobSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}

	if spec.Parallelism != nil && *spec.Parallelism < 0 {
		allErrs = append(allErrs, errs.NewFieldInvalid("parallelism", spec.Parallelism, isNegativeErrorMsg))
	}
	if spec.Completions != nil && *spec.Completions < 0 {
		allErrs = append(allErrs, errs.NewFieldInvalid("completions", spec.Completions, isNegativeErrorMsg))
	}
	if spec.Selector == nil {
		allErrs = append(allErrs, errs.NewFieldRequired("selector"))
	} else {
		allErrs = append(allErrs, ValidatePodSelector(spec.Selector).Prefix("selector")...)
	}

	if selector, err := extensions.PodSelectorAsSelector(spec.Selector); err == nil {
		labels := labels.Set(spec.Template.Labels)
		if !selector.Matches(labels) {
			allErrs = append(allErrs, errs.NewFieldInvalid("template.metadata.labels", spec.Template.Labels, "selector does not match template"))
		}
	}

	allErrs = append(allErrs, apivalidation.ValidatePodTemplateSpec(&spec.Template).Prefix("template")...)
	if spec.Template.Spec.RestartPolicy != api.RestartPolicyOnFailure &&
		spec.Template.Spec.RestartPolicy != api.RestartPolicyNever {
		allErrs = append(allErrs, errs.NewFieldValueNotSupported("template.spec.restartPolicy",
			spec.Template.Spec.RestartPolicy, []string{string(api.RestartPolicyOnFailure), string(api.RestartPolicyNever)}))
	}
	return allErrs
}

func validateHTTPIngressRuleValue(httpIngressRuleValue *extensions.HTTPIngressRuleValue) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if len(httpIngressRuleValue.Paths) == 0 {
		allErrs = append(allErrs, errs.NewFieldRequired("paths"))
	}
	for _, rule := range httpIngressRuleValue.Paths {
		if len(rule.Path) > 0 {
			if !strings.HasPrefix(rule.Path, "/") {
				allErrs = append(allErrs, errs.NewFieldInvalid("path", rule.Path, "path must begin with /"))
			}
			// TODO: More draconian path regex validation.
			// Path must be a valid regex. This is the basic requirement.
			// In addition to this any characters not allowed in a path per
			// RFC 3986 section-3.3 cannot appear as a literal in the regex.
			// Consider the example: http://host/valid?#bar, everything after
			// the last '/' is a valid regex that matches valid#bar, which
			// isn't a valid path, because the path terminates at the first ?
			// or #. A more sophisticated form of validation would detect that
			// the user is confusing url regexes with path regexes.
			_, err := regexp.CompilePOSIX(rule.Path)
			if err != nil {
				allErrs = append(allErrs, errs.NewFieldInvalid("path", rule.Path, "httpIngressRuleValue.path must be a valid regex."))
			}
		}
		allErrs = append(allErrs, validateIngressBackend(&rule.Backend).Prefix("backend")...)
	}
	return allErrs
}

func ValidateClusterAutoscaler(autoscaler *extensions.ClusterAutoscaler) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if autoscaler.Name != "ClusterAutoscaler" {
		allErrs = append(allErrs, errs.NewFieldInvalid("name", autoscaler.Name, `name must be ClusterAutoscaler`))
	}
	if autoscaler.Namespace != api.NamespaceDefault {
		allErrs = append(allErrs, errs.NewFieldInvalid("namespace", autoscaler.Namespace, `namespace must be default`))
	}
	allErrs = append(allErrs, validateClusterAutoscalerSpec(autoscaler.Spec)...)
	return allErrs
}

// ValidateEvent makes sure that the event makes sense.
func ValidateEvent(event *api.Event) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	// TODO: There is no namespace required for node.
	if event.InvolvedObject.Kind != "Node" &&
		event.Namespace != event.InvolvedObject.Namespace {
		allErrs = append(allErrs, errs.NewFieldInvalid("involvedObject.namespace", event.InvolvedObject.Namespace, "namespace does not match involvedObject"))
	}
	if !validation.IsDNS1123Subdomain(event.Namespace) {
		allErrs = append(allErrs, errs.NewFieldInvalid("namespace", event.Namespace, ""))
	}
	return allErrs
}

func ValidateJobSpecUpdate(oldSpec, spec extensions.JobSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	allErrs = append(allErrs, ValidateJobSpec(&spec)...)
	if !api.Semantic.DeepEqual(oldSpec.Completions, spec.Completions) {
		allErrs = append(allErrs, errs.NewFieldInvalid("completions", spec.Completions, "field is immutable"))
	}
	if !api.Semantic.DeepEqual(oldSpec.Selector, spec.Selector) {
		allErrs = append(allErrs, errs.NewFieldInvalid("selector", spec.Selector, "field is immutable"))
	}
	if !api.Semantic.DeepEqual(oldSpec.Template, spec.Template) {
		allErrs = append(allErrs, errs.NewFieldInvalid("template", "[omitted]", "field is immutable"))
	}
	return allErrs
}

// ValidateDaemonSetSpec tests if required fields in the DaemonSetSpec are set.
func ValidateDaemonSetSpec(spec *extensions.DaemonSetSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}

	selector := labels.Set(spec.Selector).AsSelector()
	if selector.Empty() {
		allErrs = append(allErrs, errs.NewFieldRequired("selector"))
	}

	if spec.Template == nil {
		allErrs = append(allErrs, errs.NewFieldRequired("template"))
	} else {
		labels := labels.Set(spec.Template.Labels)
		if !selector.Matches(labels) {
			allErrs = append(allErrs, errs.NewFieldInvalid("template.metadata.labels", spec.Template.Labels, "selector does not match template"))
		}
		allErrs = append(allErrs, apivalidation.ValidatePodTemplateSpec(spec.Template).Prefix("template")...)
		// Daemons typically run on more than one node, so mark Read-Write persistent disks as invalid.
		allErrs = append(allErrs, apivalidation.ValidateReadOnlyPersistentDisks(spec.Template.Spec.Volumes).Prefix("template.spec.volumes")...)
		// RestartPolicy has already been first-order validated as per ValidatePodTemplateSpec().
		if spec.Template.Spec.RestartPolicy != api.RestartPolicyAlways {
			allErrs = append(allErrs, errs.NewFieldValueNotSupported("template.spec.restartPolicy", spec.Template.Spec.RestartPolicy, []string{string(api.RestartPolicyAlways)}))
		}
	}
	return allErrs
}

func validateHorizontalPodAutoscalerSpec(autoscaler extensions.HorizontalPodAutoscalerSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if autoscaler.MinReplicas != nil && *autoscaler.MinReplicas < 1 {
		allErrs = append(allErrs, errs.NewFieldInvalid("minReplicas", autoscaler.MinReplicas, `must be bigger or equal to 1`))
	}
	if autoscaler.MaxReplicas < 1 {
		allErrs = append(allErrs, errs.NewFieldInvalid("maxReplicas", autoscaler.MaxReplicas, `must be bigger or equal to 1`))
	}
	if autoscaler.MinReplicas != nil && autoscaler.MaxReplicas < *autoscaler.MinReplicas {
		allErrs = append(allErrs, errs.NewFieldInvalid("maxReplicas", autoscaler.MaxReplicas, `must be bigger or equal to minReplicas`))
	}
	if autoscaler.CPUUtilization != nil && autoscaler.CPUUtilization.TargetPercentage < 1 {
		allErrs = append(allErrs, errs.NewFieldInvalid("cpuUtilization.targetPercentage", autoscaler.CPUUtilization.TargetPercentage, `must be bigger or equal to 1`))
	}
	return allErrs
}

func ValidateThirdPartyResourceData(obj *extensions.ThirdPartyResourceData) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if len(obj.Name) == 0 {
		allErrs = append(allErrs, errs.NewFieldInvalid("name", obj.Name, "name must be non-empty"))
	}
	return allErrs
}

func ValidatePodSelectorRequirement(sr extensions.PodSelectorRequirement) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	switch sr.Operator {
	case extensions.PodSelectorOpIn, extensions.PodSelectorOpNotIn:
		if len(sr.Values) == 0 {
			allErrs = append(allErrs, errs.NewFieldInvalid("values", sr.Values, "must be non-empty when operator is In or NotIn"))
		}
	case extensions.PodSelectorOpExists, extensions.PodSelectorOpDoesNotExist:
		if len(sr.Values) > 0 {
			allErrs = append(allErrs, errs.NewFieldInvalid("values", sr.Values, "must be empty when operator is Exists or DoesNotExist"))
		}
	default:
		allErrs = append(allErrs, errs.NewFieldInvalid("operator", sr.Operator, "not a valid pod selector operator"))
	}
	allErrs = append(allErrs, apivalidation.ValidateLabelName(sr.Key, "key")...)
	return allErrs
}

func ValidateThirdPartyResource(obj *extensions.ThirdPartyResource) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if len(obj.Name) == 0 {
		allErrs = append(allErrs, errs.NewFieldInvalid("name", obj.Name, "name must be non-empty"))
	}
	versions := sets.String{}
	for ix := range obj.Versions {
		version := &obj.Versions[ix]
		if len(version.Name) == 0 {
			allErrs = append(allErrs, errs.NewFieldInvalid("name", version, "name can not be empty"))
		}
		if versions.Has(version.Name) {
			allErrs = append(allErrs, errs.NewFieldDuplicate("version", version))
		}
		versions.Insert(version.Name)
	}
	return allErrs
}

func IsNotMoreThan100Percent(intOrStringValue util.IntOrString, fieldName string) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	value, isPercent := getPercentValue(intOrStringValue)
	if !isPercent || value <= 100 {
		return nil
	}
	allErrs = append(allErrs, errs.NewFieldInvalid(fieldName, intOrStringValue, "should not be more than 100%"))
	return allErrs
}

func validateIngressRules(IngressRules []extensions.IngressRule) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if len(IngressRules) == 0 {
		return append(allErrs, errs.NewFieldRequired("IngressRules"))
	}
	for _, ih := range IngressRules {
		if len(ih.Host) > 0 {
			// TODO: Ports and ips are allowed in the host part of a url
			// according to RFC 3986, consider allowing them.
			if valid, errMsg := apivalidation.NameIsDNSSubdomain(ih.Host, false); !valid {
				allErrs = append(allErrs, errs.NewFieldInvalid("host", ih.Host, errMsg))
			}
			if isIP := (net.ParseIP(ih.Host) != nil); isIP {
				allErrs = append(allErrs, errs.NewFieldInvalid("host", ih.Host, "Host must be a DNS name, not ip address"))
			}
		}
		allErrs = append(allErrs, validateIngressRuleValue(&ih.IngressRuleValue).Prefix("ingressRule")...)
	}
	return allErrs
}

// ParseWatchResourceVersion takes a resource version argument and converts it to
// the etcd version we should pass to helper.Watch(). Because resourceVersion is
// an opaque value, the default watch behavior for non-zero watch is to watch
// the next value (if you pass "1", you will see updates from "2" onwards).
func ParseWatchResourceVersion(resourceVersion, kind string) (uint64, error) {
	if resourceVersion == "" || resourceVersion == "0" {
		return 0, nil
	}
	version, err := strconv.ParseUint(resourceVersion, 10, 64)
	if err != nil {
		// TODO: Does this need to be a ValidationErrorList?  I can't convince myself it does.
		return 0, errors.NewInvalid(kind, "", fielderrors.ValidationErrorList{fielderrors.NewFieldInvalid("resourceVersion", resourceVersion, err.Error())})
	}
	return version + 1, nil
}

func ValidatePositiveIntOrPercent(intOrPercent util.IntOrString, fieldName string) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if intOrPercent.Kind == util.IntstrString {
		if !validation.IsValidPercent(intOrPercent.StrVal) {
			allErrs = append(allErrs, errs.NewFieldInvalid(fieldName, intOrPercent, "value should be int(5) or percentage(5%)"))
		}

	} else if intOrPercent.Kind == util.IntstrInt {
		allErrs = append(allErrs, apivalidation.ValidatePositiveField(int64(intOrPercent.IntVal), fieldName)...)
	}
	return allErrs
}

// validateIngressBackend tests if a given backend is valid.
func validateIngressBackend(backend *extensions.IngressBackend) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}

	// All backends must reference a single local service by name, and a single service port by name or number.
	if len(backend.ServiceName) == 0 {
		return append(allErrs, errs.NewFieldRequired("serviceName"))
	} else if ok, errMsg := apivalidation.ValidateServiceName(backend.ServiceName, false); !ok {
		allErrs = append(allErrs, errs.NewFieldInvalid("serviceName", backend.ServiceName, errMsg))
	}
	if backend.ServicePort.Kind == util.IntstrString {
		if !utilvalidation.IsDNS1123Label(backend.ServicePort.StrVal) {
			allErrs = append(allErrs, errs.NewFieldInvalid("servicePort", backend.ServicePort.StrVal, apivalidation.DNS1123LabelErrorMsg))
		}
		if !utilvalidation.IsValidPortName(backend.ServicePort.StrVal) {
			allErrs = append(allErrs, errs.NewFieldInvalid("servicePort", backend.ServicePort.StrVal, apivalidation.PortNameErrorMsg))
		}
	} else if !utilvalidation.IsValidPortNum(backend.ServicePort.IntVal) {
		allErrs = append(allErrs, errs.NewFieldInvalid("servicePort", backend.ServicePort, apivalidation.PortRangeErrorMsg))
	}
	return allErrs
}

// ValidateIngressSpec tests if required fields in the IngressSpec are set.
func ValidateIngressSpec(spec *extensions.IngressSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	// TODO: Is a default backend mandatory?
	if spec.Backend != nil {
		allErrs = append(allErrs, validateIngressBackend(spec.Backend).Prefix("backend")...)
	} else if len(spec.Rules) == 0 {
		allErrs = append(allErrs, errs.NewFieldInvalid("rules", spec.Rules, "Either a default backend or a set of host rules are required for ingress."))
	}
	if len(spec.Rules) > 0 {
		allErrs = append(allErrs, validateIngressRules(spec.Rules).Prefix("rules")...)
	}
	return allErrs
}

// ValidateDaemonSetTemplateUpdate tests that certain fields in the daemon set's pod template are not updated.
func ValidateDaemonSetTemplateUpdate(oldPodTemplate, podTemplate *api.PodTemplateSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	podSpec := podTemplate.Spec
	// podTemplate.Spec is not a pointer, so we can modify NodeSelector and NodeName directly.
	podSpec.NodeSelector = oldPodTemplate.Spec.NodeSelector
	podSpec.NodeName = oldPodTemplate.Spec.NodeName
	// In particular, we do not allow updates to container images at this point.
	if !api.Semantic.DeepEqual(oldPodTemplate.Spec, podSpec) {
		// TODO: Pinpoint the specific field that causes the invalid error after we have strategic merge diff
		allErrs = append(allErrs, errs.NewFieldInvalid("spec", "content of spec is not printed out, please refer to the \"details\"", "may not update fields other than spec.nodeSelector"))
	}
	return allErrs
}

func ValidateRollingUpdateDeployment(rollingUpdate *extensions.RollingUpdateDeployment, fieldName string) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	allErrs = append(allErrs, ValidatePositiveIntOrPercent(rollingUpdate.MaxUnavailable, fieldName+"maxUnavailable")...)
	allErrs = append(allErrs, ValidatePositiveIntOrPercent(rollingUpdate.MaxSurge, fieldName+".maxSurge")...)
	if getIntOrPercentValue(rollingUpdate.MaxUnavailable) == 0 && getIntOrPercentValue(rollingUpdate.MaxSurge) == 0 {
		// Both MaxSurge and MaxUnavailable cannot be zero.
		allErrs = append(allErrs, errs.NewFieldInvalid(fieldName+".maxUnavailable", rollingUpdate.MaxUnavailable, "cannot be 0 when maxSurge is 0 as well"))
	}
	// Validate that MaxUnavailable is not more than 100%.
	allErrs = append(allErrs, IsNotMoreThan100Percent(rollingUpdate.MaxUnavailable, fieldName+".maxUnavailable")...)
	allErrs = append(allErrs, apivalidation.ValidatePositiveField(int64(rollingUpdate.MinReadySeconds), fieldName+".minReadySeconds")...)
	return allErrs
}

func validateClusterAutoscalerSpec(spec extensions.ClusterAutoscalerSpec) errs.ValidationErrorList {
	allErrs := errs.ValidationErrorList{}
	if spec.MinNodes < 0 {
		allErrs = append(allErrs, errs.NewFieldInvalid("minNodes", spec.MinNodes, `must be non-negative`))
	}
	if spec.MaxNodes < spec.MinNodes {
		allErrs = append(allErrs, errs.NewFieldInvalid("maxNodes", spec.MaxNodes, `must be bigger or equal to minNodes`))
	}
	if len(spec.TargetUtilization) == 0 {
		allErrs = append(allErrs, errs.NewFieldRequired("targetUtilization"))
	}
	for _, target := range spec.TargetUtilization {
		if len(target.Resource) == 0 {
			allErrs = append(allErrs, errs.NewFieldRequired("targetUtilization.resource"))
		}
		if target.Value <= 0 {
			allErrs = append(allErrs, errs.NewFieldInvalid("targetUtilization.value", target.Value, "must be greater than 0"))
		}
		if target.Value > 1 {
			allErrs = append(allErrs, errs.NewFieldInvalid("targetUtilization.value", target.Value, "must be less or equal 1"))
		}
	}
	return allErrs
}