pkg/api/pod/warnings.go - third_party/kubernetes - Git at Google

 /*
 Copyright 2021 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 pod

 import (
 	"context"
 	"fmt"
 	"strings"

 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	nodeapi "k8s.io/kubernetes/pkg/api/node"
 	pvcutil "k8s.io/kubernetes/pkg/api/persistentvolumeclaim"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/core/pods"
 	"k8s.io/kubernetes/pkg/features"
 )

 func GetWarningsForPod(ctx context.Context, pod, oldPod *api.Pod) []string {
 	if pod == nil {
 		return nil
 	}

 	var (
 		oldSpec *api.PodSpec
 		oldMeta *metav1.ObjectMeta
 	)
 	if oldPod != nil {
 		oldSpec = &oldPod.Spec
 		oldMeta = &oldPod.ObjectMeta
 	}
 	return warningsForPodSpecAndMeta(nil, &pod.Spec, &pod.ObjectMeta, oldSpec, oldMeta)
 }

 func GetWarningsForPodTemplate(ctx context.Context, fieldPath *field.Path, podTemplate, oldPodTemplate *api.PodTemplateSpec) []string {
 	if podTemplate == nil {
 		return nil
 	}

 	var (
 		oldSpec *api.PodSpec
 		oldMeta *metav1.ObjectMeta
 	)
 	if oldPodTemplate != nil {
 		oldSpec = &oldPodTemplate.Spec
 		oldMeta = &oldPodTemplate.ObjectMeta
 	}
 	return warningsForPodSpecAndMeta(fieldPath, &podTemplate.Spec, &podTemplate.ObjectMeta, oldSpec, oldMeta)
 }

 var deprecatedAnnotations = []struct {
 	key     string
 	prefix  string
 	message string
 }{
 	{
 		key:     `scheduler.alpha.kubernetes.io/critical-pod`,
 		message: `non-functional in v1.16+; use the "priorityClassName" field instead`,
 	},
 	{
 		key:     `security.alpha.kubernetes.io/sysctls`,
 		message: `non-functional in v1.11+; use the "sysctls" field instead`,
 	},
 	{
 		key:     `security.alpha.kubernetes.io/unsafe-sysctls`,
 		message: `non-functional in v1.11+; use the "sysctls" field instead`,
 	},
 }

 func warningsForPodSpecAndMeta(fieldPath *field.Path, podSpec *api.PodSpec, meta *metav1.ObjectMeta, oldPodSpec *api.PodSpec, oldMeta *metav1.ObjectMeta) []string {
 	var warnings []string

 	// use of deprecated node labels in selectors/affinity/topology
 	for k := range podSpec.NodeSelector {
 		if msg, deprecated := nodeapi.GetNodeLabelDeprecatedMessage(k); deprecated {
 			warnings = append(warnings, fmt.Sprintf("%s: %s", fieldPath.Child("spec", "nodeSelector").Key(k), msg))
 		}
 	}
 	if podSpec.Affinity != nil && podSpec.Affinity.NodeAffinity != nil {
 		n := podSpec.Affinity.NodeAffinity
 		if n.RequiredDuringSchedulingIgnoredDuringExecution != nil {
 			termFldPath := fieldPath.Child("spec", "affinity", "nodeAffinity", "requiredDuringSchedulingIgnoredDuringExecution", "nodeSelectorTerms")
 			for i, term := range n.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms {
 				warnings = append(warnings, nodeapi.GetWarningsForNodeSelectorTerm(term, termFldPath.Index(i))...)
 			}
 		}
 		preferredFldPath := fieldPath.Child("spec", "affinity", "nodeAffinity", "preferredDuringSchedulingIgnoredDuringExecution")
 		for i, term := range n.PreferredDuringSchedulingIgnoredDuringExecution {
 			warnings = append(warnings, nodeapi.GetWarningsForNodeSelectorTerm(term.Preference, preferredFldPath.Index(i).Child("preference"))...)
 		}
 	}
 	for i, t := range podSpec.TopologySpreadConstraints {
 		if msg, deprecated := nodeapi.GetNodeLabelDeprecatedMessage(t.TopologyKey); deprecated {
 			warnings = append(warnings, fmt.Sprintf(
 				"%s: %s is %s",
 				fieldPath.Child("spec", "topologySpreadConstraints").Index(i).Child("topologyKey"),
 				t.TopologyKey,
 				msg,
 			))
 		}

 		// warn if labelSelector is empty which is no-match.
 		if t.LabelSelector == nil {
 			warnings = append(warnings, fmt.Sprintf("%s: a null labelSelector results in matching no pod", fieldPath.Child("spec", "topologySpreadConstraints").Index(i).Child("labelSelector")))
 		}
 	}

 	// use of deprecated annotations
 	for _, deprecated := range deprecatedAnnotations {
 		if _, exists := meta.Annotations[deprecated.key]; exists {
 			warnings = append(warnings, fmt.Sprintf("%s: %s", fieldPath.Child("metadata", "annotations").Key(deprecated.key), deprecated.message))
 		}
 		if len(deprecated.prefix) > 0 {
 			for k := range meta.Annotations {
 				if strings.HasPrefix(k, deprecated.prefix) {
 					warnings = append(warnings, fmt.Sprintf("%s: %s", fieldPath.Child("metadata", "annotations").Key(k), deprecated.message))
 					break
 				}
 			}
 		}
 	}

 	// deprecated and removed volume plugins
 	for i, v := range podSpec.Volumes {
 		if v.PhotonPersistentDisk != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.11, non-functional in v1.16+", fieldPath.Child("spec", "volumes").Index(i).Child("photonPersistentDisk")))
 		}
 		if v.GitRepo != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.11", fieldPath.Child("spec", "volumes").Index(i).Child("gitRepo")))
 		}
 		if v.ScaleIO != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.16, non-functional in v1.22+", fieldPath.Child("spec", "volumes").Index(i).Child("scaleIO")))
 		}
 		if v.Flocker != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.22, non-functional in v1.25+", fieldPath.Child("spec", "volumes").Index(i).Child("flocker")))
 		}
 		if v.StorageOS != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.22, non-functional in v1.25+", fieldPath.Child("spec", "volumes").Index(i).Child("storageOS")))
 		}
 		if v.Quobyte != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.22, non-functional in v1.25+", fieldPath.Child("spec", "volumes").Index(i).Child("quobyte")))
 		}
 		if v.Glusterfs != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.25, non-functional in v1.26+", fieldPath.Child("spec", "volumes").Index(i).Child("glusterfs")))
 		}
 		if v.Ephemeral != nil && v.Ephemeral.VolumeClaimTemplate != nil {
 			warnings = append(warnings, pvcutil.GetWarningsForPersistentVolumeClaimSpec(fieldPath.Child("spec", "volumes").Index(i).Child("ephemeral").Child("volumeClaimTemplate").Child("spec"), v.Ephemeral.VolumeClaimTemplate.Spec)...)
 		}
 		if v.CephFS != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.28, non-functional in v1.31+", fieldPath.Child("spec", "volumes").Index(i).Child("cephfs")))
 		}
 		if v.RBD != nil {
 			warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.28, non-functional in v1.31+", fieldPath.Child("spec", "volumes").Index(i).Child("rbd")))
 		}
 	}

 	// duplicate hostAliases (#91670, #58477)
 	if len(podSpec.HostAliases) > 1 {
 		items := sets.New[string]()
 		for i, item := range podSpec.HostAliases {
 			if items.Has(item.IP) {
 				warnings = append(warnings, fmt.Sprintf("%s: duplicate ip %q", fieldPath.Child("spec", "hostAliases").Index(i).Child("ip"), item.IP))
 			} else {
 				items.Insert(item.IP)
 			}
 		}
 	}

 	// duplicate imagePullSecrets (#91629, #58477)
 	if len(podSpec.ImagePullSecrets) > 1 {
 		items := sets.New[string]()
 		for i, item := range podSpec.ImagePullSecrets {
 			if items.Has(item.Name) {
 				warnings = append(warnings, fmt.Sprintf("%s: duplicate name %q", fieldPath.Child("spec", "imagePullSecrets").Index(i).Child("name"), item.Name))
 			} else {
 				items.Insert(item.Name)
 			}
 		}
 	}
 	// imagePullSecrets with empty name (#99454#issuecomment-787838112)
 	for i, item := range podSpec.ImagePullSecrets {
 		if len(item.Name) == 0 {
 			warnings = append(warnings, fmt.Sprintf("%s: invalid empty name %q", fieldPath.Child("spec", "imagePullSecrets").Index(i).Child("name"), item.Name))
 		}
 	}

 	// fractional memory/ephemeral-storage requests/limits (#79950, #49442, #18538)
 	if value, ok := podSpec.Overhead[api.ResourceMemory]; ok && value.MilliValue()%int64(1000) != int64(0) {
 		warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", fieldPath.Child("spec", "overhead").Key(string(api.ResourceMemory)), value.String()))
 	}
 	if value, ok := podSpec.Overhead[api.ResourceEphemeralStorage]; ok && value.MilliValue()%int64(1000) != int64(0) {
 		warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", fieldPath.Child("spec", "overhead").Key(string(api.ResourceEphemeralStorage)), value.String()))
 	}

 	// use of pod seccomp annotation without accompanying field
 	if podSpec.SecurityContext == nil || podSpec.SecurityContext.SeccompProfile == nil {
 		if _, exists := meta.Annotations[api.SeccompPodAnnotationKey]; exists {
 			warnings = append(warnings, fmt.Sprintf(`%s: non-functional in v1.27+; use the "seccompProfile" field instead`, fieldPath.Child("metadata", "annotations").Key(api.SeccompPodAnnotationKey)))
 		}
 	}
 	hasPodAppArmorProfile := podSpec.SecurityContext != nil && podSpec.SecurityContext.AppArmorProfile != nil

 	pods.VisitContainersWithPath(podSpec, fieldPath.Child("spec"), func(c *api.Container, p *field.Path) bool {
 		// use of container seccomp annotation without accompanying field
 		if c.SecurityContext == nil || c.SecurityContext.SeccompProfile == nil {
 			if _, exists := meta.Annotations[api.SeccompContainerAnnotationKeyPrefix+c.Name]; exists {
 				warnings = append(warnings, fmt.Sprintf(`%s: non-functional in v1.27+; use the "seccompProfile" field instead`, fieldPath.Child("metadata", "annotations").Key(api.SeccompContainerAnnotationKeyPrefix+c.Name)))
 			}
 		}

 		// use of container AppArmor annotation without accompanying field
 		if utilfeature.DefaultFeatureGate.Enabled(features.AppArmorFields) {
 			isPodTemplate := fieldPath != nil // Pod warnings are emitted through applyAppArmorVersionSkew instead.
 			hasAppArmorField := hasPodAppArmorProfile || (c.SecurityContext != nil && c.SecurityContext.AppArmorProfile != nil)
 			if isPodTemplate && !hasAppArmorField {
 				key := api.DeprecatedAppArmorAnnotationKeyPrefix + c.Name
 				if _, exists := meta.Annotations[key]; exists {
 					warnings = append(warnings, fmt.Sprintf(`%s: deprecated since v1.30; use the "appArmorProfile" field instead`, fieldPath.Child("metadata", "annotations").Key(key)))
 				}
 			}
 		}

 		// fractional memory/ephemeral-storage requests/limits (#79950, #49442, #18538)
 		if value, ok := c.Resources.Limits[api.ResourceMemory]; ok && value.MilliValue()%int64(1000) != int64(0) {
 			warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "limits").Key(string(api.ResourceMemory)), value.String()))
 		}
 		if value, ok := c.Resources.Requests[api.ResourceMemory]; ok && value.MilliValue()%int64(1000) != int64(0) {
 			warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "requests").Key(string(api.ResourceMemory)), value.String()))
 		}
 		if value, ok := c.Resources.Limits[api.ResourceEphemeralStorage]; ok && value.MilliValue()%int64(1000) != int64(0) {
 			warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "limits").Key(string(api.ResourceEphemeralStorage)), value.String()))
 		}
 		if value, ok := c.Resources.Requests[api.ResourceEphemeralStorage]; ok && value.MilliValue()%int64(1000) != int64(0) {
 			warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "requests").Key(string(api.ResourceEphemeralStorage)), value.String()))
 		}

 		// duplicate containers[*].env (#86163, #93266, #58477)
 		if len(c.Env) > 1 {
 			items := sets.New[string]()
 			for i, item := range c.Env {
 				if items.Has(item.Name) {
 					// a previous value exists, but it might be OK
 					bad := false
 					ref := fmt.Sprintf("$(%s)", item.Name) // what does a ref to this name look like
 					// if we are replacing it with a valueFrom, warn
 					if item.ValueFrom != nil {
 						bad = true
 					}
 					// if this is X="$(X)", warn
 					if item.Value == ref {
 						bad = true
 					}
 					// if the new value does not contain a reference to the old
 					// value (e.g. X="abc"; X="$(X)123"), warn
 					if !strings.Contains(item.Value, ref) {
 						bad = true
 					}
 					if bad {
 						warnings = append(warnings, fmt.Sprintf("%s: hides previous definition of %q, which may be dropped when using apply", p.Child("env").Index(i), item.Name))
 					}
 				} else {
 					items.Insert(item.Name)
 				}
 			}
 		}
 		return true
 	})

 	type portBlock struct {
 		field *field.Path
 		port  api.ContainerPort
 	}

 	// Accumulate ports across all containers
 	allPorts := map[string][]portBlock{}
 	pods.VisitContainersWithPath(podSpec, fieldPath.Child("spec"), func(c *api.Container, fldPath *field.Path) bool {
 		for i, port := range c.Ports {
 			if port.HostIP != "" && port.HostPort == 0 {
 				warnings = append(warnings, fmt.Sprintf("%s: hostIP set without hostPort: %+v",
 					fldPath.Child("ports").Index(i), port))
 			}
 			k := fmt.Sprintf("%d/%s", port.ContainerPort, port.Protocol)
 			if others, found := allPorts[k]; found {
 				// Someone else has this protcol+port, but it still might not be a conflict.
 				for _, other := range others {
 					if port.HostIP == other.port.HostIP && port.HostPort == other.port.HostPort {
 						// Exactly-equal is obvious. Validation should already filter for this except when these are unspecified.
 						warnings = append(warnings, fmt.Sprintf("%s: duplicate port definition with %s", fldPath.Child("ports").Index(i), other.field))
 					} else if port.HostPort == 0 || other.port.HostPort == 0 {
 						// HostPort = 0 is redundant with any other value, which is odd but not really dangerous.  HostIP doesn't matter here.
 						warnings = append(warnings, fmt.Sprintf("%s: overlapping port definition with %s", fldPath.Child("ports").Index(i), other.field))
 					} else if a, b := port.HostIP == "", other.port.HostIP == ""; port.HostPort == other.port.HostPort && ((a || b) && !(a && b)) {
 						// If the HostPorts are the same and either HostIP is not specified while the other is not, the behavior is undefined.
 						warnings = append(warnings, fmt.Sprintf("%s: dangerously ambiguous port definition with %s", fldPath.Child("ports").Index(i), other.field))
 					}
 				}
 				allPorts[k] = append(allPorts[k], portBlock{field: fldPath.Child("ports").Index(i), port: port})
 			} else {
 				allPorts[k] = []portBlock{{field: fldPath.Child("ports").Index(i), port: port}}
 			}
 		}
 		return true
 	})

 	// warn if the terminationGracePeriodSeconds is negative.
 	if podSpec.TerminationGracePeriodSeconds != nil && *podSpec.TerminationGracePeriodSeconds < 0 {
 		warnings = append(warnings, fmt.Sprintf("%s: must be >= 0; negative values are invalid and will be treated as 1", fieldPath.Child("spec", "terminationGracePeriodSeconds")))
 	}

 	if podSpec.Affinity != nil {
 		if affinity := podSpec.Affinity.PodAffinity; affinity != nil {
 			warnings = append(warnings, warningsForPodAffinityTerms(affinity.RequiredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAffinity", "requiredDuringSchedulingIgnoredDuringExecution"))...)
 			warnings = append(warnings, warningsForWeightedPodAffinityTerms(affinity.PreferredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAffinity", "preferredDuringSchedulingIgnoredDuringExecution"))...)
 		}
 		if affinity := podSpec.Affinity.PodAntiAffinity; affinity != nil {
 			warnings = append(warnings, warningsForPodAffinityTerms(affinity.RequiredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAntiAffinity", "requiredDuringSchedulingIgnoredDuringExecution"))...)
 			warnings = append(warnings, warningsForWeightedPodAffinityTerms(affinity.PreferredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAntiAffinity", "preferredDuringSchedulingIgnoredDuringExecution"))...)
 		}
 	}

 	return warnings
 }

 func warningsForPodAffinityTerms(terms []api.PodAffinityTerm, fieldPath *field.Path) []string {
 	var warnings []string
 	for i, t := range terms {
 		if t.LabelSelector == nil {
 			warnings = append(warnings, fmt.Sprintf("%s: a null labelSelector results in matching no pod", fieldPath.Index(i).Child("labelSelector")))
 		}
 	}
 	return warnings
 }

 func warningsForWeightedPodAffinityTerms(terms []api.WeightedPodAffinityTerm, fieldPath *field.Path) []string {
 	var warnings []string
 	for i, t := range terms {
 		// warn if labelSelector is empty which is no-match.
 		if t.PodAffinityTerm.LabelSelector == nil {
 			warnings = append(warnings, fmt.Sprintf("%s: a null labelSelector results in matching no pod", fieldPath.Index(i).Child("podAffinityTerm", "labelSelector")))
 		}
 	}
 	return warnings
 }
	/*
	Copyright 2021 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 pod

	import (
	"context"
	"fmt"
	"strings"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/apimachinery/pkg/util/validation/field"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	nodeapi "k8s.io/kubernetes/pkg/api/node"
	pvcutil "k8s.io/kubernetes/pkg/api/persistentvolumeclaim"
	api "k8s.io/kubernetes/pkg/apis/core"
	"k8s.io/kubernetes/pkg/apis/core/pods"
	"k8s.io/kubernetes/pkg/features"
	)

	func GetWarningsForPod(ctx context.Context, pod, oldPod *api.Pod) []string {
	if pod == nil {
	return nil
	}

	var (
	oldSpec *api.PodSpec
	oldMeta *metav1.ObjectMeta
	)
	if oldPod != nil {
	oldSpec = &oldPod.Spec
	oldMeta = &oldPod.ObjectMeta
	}
	return warningsForPodSpecAndMeta(nil, &pod.Spec, &pod.ObjectMeta, oldSpec, oldMeta)
	}

	func GetWarningsForPodTemplate(ctx context.Context, fieldPath field.Path, podTemplate, oldPodTemplate api.PodTemplateSpec) []string {
	if podTemplate == nil {
	return nil
	}

	var (
	oldSpec *api.PodSpec
	oldMeta *metav1.ObjectMeta
	)
	if oldPodTemplate != nil {
	oldSpec = &oldPodTemplate.Spec
	oldMeta = &oldPodTemplate.ObjectMeta
	}
	return warningsForPodSpecAndMeta(fieldPath, &podTemplate.Spec, &podTemplate.ObjectMeta, oldSpec, oldMeta)
	}

	var deprecatedAnnotations = []struct {
	key string
	prefix string
	message string
	}{
	{
	key: `scheduler.alpha.kubernetes.io/critical-pod`,
	message: `non-functional in v1.16+; use the "priorityClassName" field instead`,
	},
	{
	key: `security.alpha.kubernetes.io/sysctls`,
	message: `non-functional in v1.11+; use the "sysctls" field instead`,
	},
	{
	key: `security.alpha.kubernetes.io/unsafe-sysctls`,
	message: `non-functional in v1.11+; use the "sysctls" field instead`,
	},
	}

	func warningsForPodSpecAndMeta(fieldPath field.Path, podSpec api.PodSpec, meta metav1.ObjectMeta, oldPodSpec api.PodSpec, oldMeta *metav1.ObjectMeta) []string {
	var warnings []string

	// use of deprecated node labels in selectors/affinity/topology
	for k := range podSpec.NodeSelector {
	if msg, deprecated := nodeapi.GetNodeLabelDeprecatedMessage(k); deprecated {
	warnings = append(warnings, fmt.Sprintf("%s: %s", fieldPath.Child("spec", "nodeSelector").Key(k), msg))
	}
	}
	if podSpec.Affinity != nil && podSpec.Affinity.NodeAffinity != nil {
	n := podSpec.Affinity.NodeAffinity
	if n.RequiredDuringSchedulingIgnoredDuringExecution != nil {
	termFldPath := fieldPath.Child("spec", "affinity", "nodeAffinity", "requiredDuringSchedulingIgnoredDuringExecution", "nodeSelectorTerms")
	for i, term := range n.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms {
	warnings = append(warnings, nodeapi.GetWarningsForNodeSelectorTerm(term, termFldPath.Index(i))...)
	}
	}
	preferredFldPath := fieldPath.Child("spec", "affinity", "nodeAffinity", "preferredDuringSchedulingIgnoredDuringExecution")
	for i, term := range n.PreferredDuringSchedulingIgnoredDuringExecution {
	warnings = append(warnings, nodeapi.GetWarningsForNodeSelectorTerm(term.Preference, preferredFldPath.Index(i).Child("preference"))...)
	}
	}
	for i, t := range podSpec.TopologySpreadConstraints {
	if msg, deprecated := nodeapi.GetNodeLabelDeprecatedMessage(t.TopologyKey); deprecated {
	warnings = append(warnings, fmt.Sprintf(
	"%s: %s is %s",
	fieldPath.Child("spec", "topologySpreadConstraints").Index(i).Child("topologyKey"),
	t.TopologyKey,
	msg,
	))
	}

	// warn if labelSelector is empty which is no-match.
	if t.LabelSelector == nil {
	warnings = append(warnings, fmt.Sprintf("%s: a null labelSelector results in matching no pod", fieldPath.Child("spec", "topologySpreadConstraints").Index(i).Child("labelSelector")))
	}
	}

	// use of deprecated annotations
	for _, deprecated := range deprecatedAnnotations {
	if _, exists := meta.Annotations[deprecated.key]; exists {
	warnings = append(warnings, fmt.Sprintf("%s: %s", fieldPath.Child("metadata", "annotations").Key(deprecated.key), deprecated.message))
	}
	if len(deprecated.prefix) > 0 {
	for k := range meta.Annotations {
	if strings.HasPrefix(k, deprecated.prefix) {
	warnings = append(warnings, fmt.Sprintf("%s: %s", fieldPath.Child("metadata", "annotations").Key(k), deprecated.message))
	break
	}
	}
	}
	}

	// deprecated and removed volume plugins
	for i, v := range podSpec.Volumes {
	if v.PhotonPersistentDisk != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.11, non-functional in v1.16+", fieldPath.Child("spec", "volumes").Index(i).Child("photonPersistentDisk")))
	}
	if v.GitRepo != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.11", fieldPath.Child("spec", "volumes").Index(i).Child("gitRepo")))
	}
	if v.ScaleIO != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.16, non-functional in v1.22+", fieldPath.Child("spec", "volumes").Index(i).Child("scaleIO")))
	}
	if v.Flocker != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.22, non-functional in v1.25+", fieldPath.Child("spec", "volumes").Index(i).Child("flocker")))
	}
	if v.StorageOS != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.22, non-functional in v1.25+", fieldPath.Child("spec", "volumes").Index(i).Child("storageOS")))
	}
	if v.Quobyte != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.22, non-functional in v1.25+", fieldPath.Child("spec", "volumes").Index(i).Child("quobyte")))
	}
	if v.Glusterfs != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.25, non-functional in v1.26+", fieldPath.Child("spec", "volumes").Index(i).Child("glusterfs")))
	}
	if v.Ephemeral != nil && v.Ephemeral.VolumeClaimTemplate != nil {
	warnings = append(warnings, pvcutil.GetWarningsForPersistentVolumeClaimSpec(fieldPath.Child("spec", "volumes").Index(i).Child("ephemeral").Child("volumeClaimTemplate").Child("spec"), v.Ephemeral.VolumeClaimTemplate.Spec)...)
	}
	if v.CephFS != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.28, non-functional in v1.31+", fieldPath.Child("spec", "volumes").Index(i).Child("cephfs")))
	}
	if v.RBD != nil {
	warnings = append(warnings, fmt.Sprintf("%s: deprecated in v1.28, non-functional in v1.31+", fieldPath.Child("spec", "volumes").Index(i).Child("rbd")))
	}
	}

	// duplicate hostAliases (#91670, #58477)
	if len(podSpec.HostAliases) > 1 {
	items := sets.New[string]()
	for i, item := range podSpec.HostAliases {
	if items.Has(item.IP) {
	warnings = append(warnings, fmt.Sprintf("%s: duplicate ip %q", fieldPath.Child("spec", "hostAliases").Index(i).Child("ip"), item.IP))
	} else {
	items.Insert(item.IP)
	}
	}
	}

	// duplicate imagePullSecrets (#91629, #58477)
	if len(podSpec.ImagePullSecrets) > 1 {
	items := sets.New[string]()
	for i, item := range podSpec.ImagePullSecrets {
	if items.Has(item.Name) {
	warnings = append(warnings, fmt.Sprintf("%s: duplicate name %q", fieldPath.Child("spec", "imagePullSecrets").Index(i).Child("name"), item.Name))
	} else {
	items.Insert(item.Name)
	}
	}
	}
	// imagePullSecrets with empty name (#99454#issuecomment-787838112)
	for i, item := range podSpec.ImagePullSecrets {
	if len(item.Name) == 0 {
	warnings = append(warnings, fmt.Sprintf("%s: invalid empty name %q", fieldPath.Child("spec", "imagePullSecrets").Index(i).Child("name"), item.Name))
	}
	}

	// fractional memory/ephemeral-storage requests/limits (#79950, #49442, #18538)
	if value, ok := podSpec.Overhead[api.ResourceMemory]; ok && value.MilliValue()%int64(1000) != int64(0) {
	warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", fieldPath.Child("spec", "overhead").Key(string(api.ResourceMemory)), value.String()))
	}
	if value, ok := podSpec.Overhead[api.ResourceEphemeralStorage]; ok && value.MilliValue()%int64(1000) != int64(0) {
	warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", fieldPath.Child("spec", "overhead").Key(string(api.ResourceEphemeralStorage)), value.String()))
	}

	// use of pod seccomp annotation without accompanying field
	if podSpec.SecurityContext == nil \|\| podSpec.SecurityContext.SeccompProfile == nil {
	if _, exists := meta.Annotations[api.SeccompPodAnnotationKey]; exists {
	warnings = append(warnings, fmt.Sprintf(`%s: non-functional in v1.27+; use the "seccompProfile" field instead`, fieldPath.Child("metadata", "annotations").Key(api.SeccompPodAnnotationKey)))
	}
	}
	hasPodAppArmorProfile := podSpec.SecurityContext != nil && podSpec.SecurityContext.AppArmorProfile != nil

	pods.VisitContainersWithPath(podSpec, fieldPath.Child("spec"), func(c api.Container, p field.Path) bool {
	// use of container seccomp annotation without accompanying field
	if c.SecurityContext == nil \|\| c.SecurityContext.SeccompProfile == nil {
	if _, exists := meta.Annotations[api.SeccompContainerAnnotationKeyPrefix+c.Name]; exists {
	warnings = append(warnings, fmt.Sprintf(`%s: non-functional in v1.27+; use the "seccompProfile" field instead`, fieldPath.Child("metadata", "annotations").Key(api.SeccompContainerAnnotationKeyPrefix+c.Name)))
	}
	}

	// use of container AppArmor annotation without accompanying field
	if utilfeature.DefaultFeatureGate.Enabled(features.AppArmorFields) {
	isPodTemplate := fieldPath != nil // Pod warnings are emitted through applyAppArmorVersionSkew instead.
	hasAppArmorField := hasPodAppArmorProfile \|\| (c.SecurityContext != nil && c.SecurityContext.AppArmorProfile != nil)
	if isPodTemplate && !hasAppArmorField {
	key := api.DeprecatedAppArmorAnnotationKeyPrefix + c.Name
	if _, exists := meta.Annotations[key]; exists {
	warnings = append(warnings, fmt.Sprintf(`%s: deprecated since v1.30; use the "appArmorProfile" field instead`, fieldPath.Child("metadata", "annotations").Key(key)))
	}
	}
	}

	// fractional memory/ephemeral-storage requests/limits (#79950, #49442, #18538)
	if value, ok := c.Resources.Limits[api.ResourceMemory]; ok && value.MilliValue()%int64(1000) != int64(0) {
	warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "limits").Key(string(api.ResourceMemory)), value.String()))
	}
	if value, ok := c.Resources.Requests[api.ResourceMemory]; ok && value.MilliValue()%int64(1000) != int64(0) {
	warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "requests").Key(string(api.ResourceMemory)), value.String()))
	}
	if value, ok := c.Resources.Limits[api.ResourceEphemeralStorage]; ok && value.MilliValue()%int64(1000) != int64(0) {
	warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "limits").Key(string(api.ResourceEphemeralStorage)), value.String()))
	}
	if value, ok := c.Resources.Requests[api.ResourceEphemeralStorage]; ok && value.MilliValue()%int64(1000) != int64(0) {
	warnings = append(warnings, fmt.Sprintf("%s: fractional byte value %q is invalid, must be an integer", p.Child("resources", "requests").Key(string(api.ResourceEphemeralStorage)), value.String()))
	}

	// duplicate containers[*].env (#86163, #93266, #58477)
	if len(c.Env) > 1 {
	items := sets.New[string]()
	for i, item := range c.Env {
	if items.Has(item.Name) {
	// a previous value exists, but it might be OK
	bad := false
	ref := fmt.Sprintf("$(%s)", item.Name) // what does a ref to this name look like
	// if we are replacing it with a valueFrom, warn
	if item.ValueFrom != nil {
	bad = true
	}
	// if this is X="$(X)", warn
	if item.Value == ref {
	bad = true
	}
	// if the new value does not contain a reference to the old
	// value (e.g. X="abc"; X="$(X)123"), warn
	if !strings.Contains(item.Value, ref) {
	bad = true
	}
	if bad {
	warnings = append(warnings, fmt.Sprintf("%s: hides previous definition of %q, which may be dropped when using apply", p.Child("env").Index(i), item.Name))
	}
	} else {
	items.Insert(item.Name)
	}
	}
	}
	return true
	})

	type portBlock struct {
	field *field.Path
	port api.ContainerPort
	}

	// Accumulate ports across all containers
	allPorts := map[string][]portBlock{}
	pods.VisitContainersWithPath(podSpec, fieldPath.Child("spec"), func(c api.Container, fldPath field.Path) bool {
	for i, port := range c.Ports {
	if port.HostIP != "" && port.HostPort == 0 {
	warnings = append(warnings, fmt.Sprintf("%s: hostIP set without hostPort: %+v",
	fldPath.Child("ports").Index(i), port))
	}
	k := fmt.Sprintf("%d/%s", port.ContainerPort, port.Protocol)
	if others, found := allPorts[k]; found {
	// Someone else has this protcol+port, but it still might not be a conflict.
	for _, other := range others {
	if port.HostIP == other.port.HostIP && port.HostPort == other.port.HostPort {
	// Exactly-equal is obvious. Validation should already filter for this except when these are unspecified.
	warnings = append(warnings, fmt.Sprintf("%s: duplicate port definition with %s", fldPath.Child("ports").Index(i), other.field))
	} else if port.HostPort == 0 \|\| other.port.HostPort == 0 {
	// HostPort = 0 is redundant with any other value, which is odd but not really dangerous. HostIP doesn't matter here.
	warnings = append(warnings, fmt.Sprintf("%s: overlapping port definition with %s", fldPath.Child("ports").Index(i), other.field))
	} else if a, b := port.HostIP == "", other.port.HostIP == ""; port.HostPort == other.port.HostPort && ((a \|\| b) && !(a && b)) {
	// If the HostPorts are the same and either HostIP is not specified while the other is not, the behavior is undefined.
	warnings = append(warnings, fmt.Sprintf("%s: dangerously ambiguous port definition with %s", fldPath.Child("ports").Index(i), other.field))
	}
	}
	allPorts[k] = append(allPorts[k], portBlock{field: fldPath.Child("ports").Index(i), port: port})
	} else {
	allPorts[k] = []portBlock{{field: fldPath.Child("ports").Index(i), port: port}}
	}
	}
	return true
	})

	// warn if the terminationGracePeriodSeconds is negative.
	if podSpec.TerminationGracePeriodSeconds != nil && *podSpec.TerminationGracePeriodSeconds < 0 {
	warnings = append(warnings, fmt.Sprintf("%s: must be >= 0; negative values are invalid and will be treated as 1", fieldPath.Child("spec", "terminationGracePeriodSeconds")))
	}

	if podSpec.Affinity != nil {
	if affinity := podSpec.Affinity.PodAffinity; affinity != nil {
	warnings = append(warnings, warningsForPodAffinityTerms(affinity.RequiredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAffinity", "requiredDuringSchedulingIgnoredDuringExecution"))...)
	warnings = append(warnings, warningsForWeightedPodAffinityTerms(affinity.PreferredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAffinity", "preferredDuringSchedulingIgnoredDuringExecution"))...)
	}
	if affinity := podSpec.Affinity.PodAntiAffinity; affinity != nil {
	warnings = append(warnings, warningsForPodAffinityTerms(affinity.RequiredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAntiAffinity", "requiredDuringSchedulingIgnoredDuringExecution"))...)
	warnings = append(warnings, warningsForWeightedPodAffinityTerms(affinity.PreferredDuringSchedulingIgnoredDuringExecution, fieldPath.Child("spec", "affinity", "podAntiAffinity", "preferredDuringSchedulingIgnoredDuringExecution"))...)
	}
	}

	return warnings
	}

	func warningsForPodAffinityTerms(terms []api.PodAffinityTerm, fieldPath *field.Path) []string {
	var warnings []string
	for i, t := range terms {
	if t.LabelSelector == nil {
	warnings = append(warnings, fmt.Sprintf("%s: a null labelSelector results in matching no pod", fieldPath.Index(i).Child("labelSelector")))
	}
	}
	return warnings
	}

	func warningsForWeightedPodAffinityTerms(terms []api.WeightedPodAffinityTerm, fieldPath *field.Path) []string {
	var warnings []string
	for i, t := range terms {
	// warn if labelSelector is empty which is no-match.
	if t.PodAffinityTerm.LabelSelector == nil {
	warnings = append(warnings, fmt.Sprintf("%s: a null labelSelector results in matching no pod", fieldPath.Index(i).Child("podAffinityTerm", "labelSelector")))
	}
	}
	return warnings
	}