podman kube play: add --validate=ignore|warn|strict flag

cmd/podman/common/completion.go

@@ -2006,6 +2006,11 @@ func AutocompleteHealthOnFailure(_ *cobra.Command, _ []string, _ string) ([]stri
 	return define.SupportedHealthCheckOnFailureActions, cobra.ShellCompDirectiveNoFileComp
 }
 
+// AutocompleteKubePlayValidate - autocomplete the values for the kube play --validate flag.
+func AutocompleteKubePlayValidate(_ *cobra.Command, _ []string, _ string) ([]string, cobra.ShellCompDirective) {
+	return entities.KubeValidateModeNames(), cobra.ShellCompDirectiveNoFileComp
+}
+
 // AutocompleteSysctl - autocomplete list all sysctl names
 func AutocompleteSysctl(_ *cobra.Command, _ []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 	var completions []string

cmd/podman/kube/play.go

@@ -21,6 +21,7 @@ import (
 	"go.podman.io/podman/v6/cmd/podman/parse"
 	"go.podman.io/podman/v6/cmd/podman/registry"
 	"go.podman.io/podman/v6/cmd/podman/utils"
+	"go.podman.io/podman/v6/cmd/podman/validate"
 	"go.podman.io/podman/v6/libpod/define"
 	"go.podman.io/podman/v6/libpod/shutdown"
 	"go.podman.io/podman/v6/pkg/annotations"
@@ -38,6 +39,7 @@ type playKubeOptionsWrapper struct {
 	CredentialsCLI string
 	StartCLI       bool
 	BuildCLI       bool
+	ValidateCLI    string
 	annotations    []string
 	macs           []string
 }
@@ -142,6 +144,12 @@ func playFlags(cmd *cobra.Command) {
 	)
 	_ = cmd.RegisterFlagCompletionFunc(usernsFlagName, common.AutocompleteUserNamespace)
 
+	playOptions.ValidateCLI = string(entities.KubeValidateIgnore)
+	validateChoice := validate.Value(&playOptions.ValidateCLI, entities.KubeValidateModeNames()...)
+	validateFlagName := "validate"
+	flags.Var(validateChoice, validateFlagName, "How to handle unrecognized YAML fields and objects: "+validateChoice.Choices())
+	_ = cmd.RegisterFlagCompletionFunc(validateFlagName, common.AutocompleteKubePlayValidate)
+
 	flags.BoolVar(&playOptions.NoHostname, "no-hostname", false, "Do not create /etc/hostname within the container, instead use the version from the image")
 	flags.BoolVar(&playOptions.NoHosts, "no-hosts", podmanConfig.ContainersConfDefaultsRO.Containers.NoHosts, "Do not create /etc/hosts within the pod's containers, instead use the version from the image")
 	flags.BoolVarP(&playOptions.Quiet, "quiet", "q", false, "Suppress output information when pulling images")
@@ -217,6 +225,8 @@ func play(cmd *cobra.Command, args []string) error {
 	if playOptions.ServiceContainer && !playOptions.StartCLI { // Sanity check to be future proof
 		return fmt.Errorf("--service-container does not work with --start=stop")
 	}
+	// The --validate value is enforced at flag-parse time by validate.Value.
+	playOptions.Validate = entities.KubeValidateMode(playOptions.ValidateCLI)
 	// TLS verification in c/image is controlled via a `types.OptionalBool`
 	// which allows for distinguishing among set-true, set-false, unspecified
 	// which is important to implement a sane way of dealing with defaults of
@@ -517,6 +527,11 @@ func kubeplay(body io.Reader) error {
 // printPlayReport goes through the report returned by KubePlay and prints it out in a human
 // friendly format.
 func printPlayReport(report *entities.PlayKubeReport) error {
+	// Print any validation warnings (for example --validate=warn) to stderr.
+	for _, warning := range report.ValidationWarnings {
+		fmt.Fprintln(os.Stderr, "Warning:", warning)
+	}
+
 	// Print volumes report
 	for i, volume := range report.Volumes {
 		if i == 0 {

docs/source/markdown/podman-kube-play.1.md.in

@@ -296,6 +296,19 @@ Start the pod after creating it, set to false to only create it.
 
 @@option userns.container
 
+#### **--validate**=*mode*
+
+Control how unrecognized YAML fields and unsupported objects are handled. Supported modes are:
+
+- **ignore**: silently skip them (default).
+- **warn**: report a warning and continue. Warnings are printed to stderr and, when using the API, returned in the play report.
+- **strict**: fail with an error.
+
+When **strict** is used, any object that fails validation halts the processing of
+further objects, but prior objects will still exist and will not be rolled back.
+For example, in a YAML file containing a Pod followed by an unsupported object, the
+Pod is created and then the command fails.
+
 #### **--wait**, **-w**
 
 Run pods and containers in the foreground. Default is false.

pkg/api/handlers/libpod/kube.go

@@ -120,6 +120,7 @@ func KubePlay(w http.ResponseWriter, r *http.Request) {
 		StaticMACs       []string          `schema:"staticMACs"`
 		TLSVerify        bool              `schema:"tlsVerify"`
 		Userns           string            `schema:"userns"`
+		Validate         string            `schema:"validate"`
 		Wait             bool              `schema:"wait"`
 		Build            bool              `schema:"build"`
 		NoPodPrefix      bool              `schema:"noPodPrefix"`
@@ -133,6 +134,13 @@ func KubePlay(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// An empty value is allowed for backward compatibility with older clients
+	// that do not send the parameter; it is treated as the default (ignore).
+	if query.Validate != "" && !entities.KubeValidateMode(query.Validate).IsValid() {
+		utils.Error(w, http.StatusBadRequest, fmt.Errorf("invalid validate value %q", query.Validate))
+		return
+	}
+
 	staticIPs := make([]net.IP, 0, len(query.StaticIPs))
 	for _, ipString := range query.StaticIPs {
 		ip := net.ParseIP(ipString)
@@ -196,6 +204,7 @@ func KubePlay(w http.ResponseWriter, r *http.Request) {
 		UseLongAnnotations: query.NoTrunc,
 		Username:           username,
 		Userns:             query.Userns,
+		Validate:           entities.KubeValidateMode(query.Validate),
 		Wait:               query.Wait,
 		ContextDir:         contextDirectory,
 		NoPodPrefix:        query.NoPodPrefix,

pkg/api/server/register_kube.go

@@ -135,6 +135,15 @@ func (s *APIServer) registerKubeHandlers(r *mux.Router) error {
 	//    type: string
 	//    description: Set the user namespace mode for the pods.
 	//  - in: query
+	//    name: validate
+	//    type: string
+	//    default: ignore
+	//    enum: [ignore, warn, strict]
+	//    description: |
+	//      How to handle unrecognized YAML fields and unsupported objects. "ignore" skips them,
+	//      "warn" returns them in the ValidationWarnings field of the response, and "strict"
+	//      fails the request. An empty value is treated as "ignore".
+	//  - in: query
 	//    name: wait
 	//    type: boolean
 	//    default: false
@@ -153,6 +162,8 @@ func (s *APIServer) registerKubeHandlers(r *mux.Router) error {
 	// responses:
 	//   200:
 	//     $ref: "#/responses/playKubeResponseLibpod"
+	//   400:
+	//     $ref: "#/responses/badParamError"
 	//   500:
 	//     $ref: "#/responses/internalError"
 	r.HandleFunc(VersionedPath("/libpod/play/kube"), s.APIHandler(libpod.PlayKube)).Methods(http.MethodPost)

pkg/bindings/kube/types.go

@@ -53,6 +53,9 @@ type PlayOptions struct {
 	NoTrunc *bool
 	// Userns - define the user namespace to use.
 	Userns *string
+	// Validate - how to handle unrecognized YAML fields and kinds:
+	// "ignore", "warn", or "strict".
+	Validate *string
 	// Force - remove volumes on --down
 	Force *bool
 	// PublishPorts - configure how to expose ports configured inside the K8S YAML file

pkg/domain/entities/play.go

@@ -7,6 +7,41 @@ import (
 	entitiesTypes "go.podman.io/podman/v6/pkg/domain/entities/types"
 )
 
+// KubeValidateMode controls how `podman kube play` handles unrecognized YAML
+// fields and unsupported kinds.
+type KubeValidateMode string
+
+const (
+	// KubeValidateIgnore silently skips unrecognized fields and kinds.
+	KubeValidateIgnore KubeValidateMode = "ignore"
+	// KubeValidateWarn logs a warning for unrecognized fields and kinds.
+	KubeValidateWarn KubeValidateMode = "warn"
+	// KubeValidateStrict fails on unrecognized fields and kinds.
+	KubeValidateStrict KubeValidateMode = "strict"
+)
+
+// supportedKubeValidateModes is the set of accepted --validate values.
+var supportedKubeValidateModes = map[KubeValidateMode]bool{
+	KubeValidateIgnore: true,
+	KubeValidateWarn:   true,
+	KubeValidateStrict: true,
+}
+
+// IsValid reports whether m is a supported validate mode.
+func (m KubeValidateMode) IsValid() bool {
+	return supportedKubeValidateModes[m]
+}
+
+// KubeValidateModeNames returns the supported --validate values as strings, in
+// order of increasing strictness, for use in shell completion and error messages.
+func KubeValidateModeNames() []string {
+	return []string{
+		string(KubeValidateIgnore),
+		string(KubeValidateWarn),
+		string(KubeValidateStrict),
+	}
+}
+
 // PlayKubeOptions controls playing kube YAML files.
 type PlayKubeOptions struct {
 	// Annotations - Annotations to add to Pods
@@ -83,6 +118,8 @@ type PlayKubeOptions struct {
 	SystemContext *types.SystemContext
 	// Do not prefix container name with pod name
 	NoPodPrefix bool
+	// Validate controls how unrecognized YAML fields and kinds are handled.
+	Validate KubeValidateMode
 }
 
 // PlayKubePod represents a single pod and associated containers created by play kube

pkg/domain/entities/types/play.go

@@ -29,6 +29,9 @@ type PlayKubeReport struct {
 	Secrets []PlaySecret
 	// ServiceContainerID - ID of the service container if one is created
 	ServiceContainerID string
+	// ValidationWarnings - non-fatal messages produced by --validate=warn, for
+	// example unrecognized YAML fields or unsupported kinds.
+	ValidationWarnings []string
 	// If set, exit with the specified exit code.
 	ExitCode *int32
 }