deprecate fn wrap, xargs, sink, source commands

cmd/config/internal/commands/cmdwrap.go

@@ -50,6 +50,8 @@ Environment Variables:
 		SilenceUsage:       true,
 		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
 		Args:               cobra.MinimumNArgs(1),
+		Deprecated: "this will no longer be available in kustomize v5.\n" +
+			"See discussion in https://github.com/kubernetes-sigs/kustomize/issues/3953.",
 	}
 	r.Command = c
 	r.XArgs = GetXArgsRunner()

cmd/config/internal/commands/cmdxargs.go

@@ -63,6 +63,8 @@ $ kyaml cat pkg/ --function-config config.yaml --wrap-kind ResourceList | kyaml
 		SilenceUsage:       true,
 		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
 		Args:               cobra.MinimumNArgs(1),
+		Deprecated: "this will no longer be available in kustomize v5.\n" +
+			"See discussion in https://github.com/kubernetes-sigs/kustomize/issues/3953.",
 	}
 	r.Command = c
 	r.Command.Flags().BoolVar(&r.EnvOnly, "env-only", false, "only add env vars, not flags")

cmd/config/internal/commands/sink.go

@@ -21,6 +21,8 @@ func GetSinkRunner(name string) *SinkRunner {
 		Example: commands.SinkExamples,
 		RunE:    r.runE,
 		Args:    cobra.MaximumNArgs(1),
+		Deprecated: "this will no longer be available in kustomize v5.\n" +
+			"See discussion in https://github.com/kubernetes-sigs/kustomize/issues/3953.",
 	}
 	runner.FixDocs(name, c)
 	r.Command = c

cmd/config/internal/commands/source.go

@@ -22,6 +22,8 @@ func GetSourceRunner(name string) *SourceRunner {
 		Long:    commands.SourceLong,
 		Example: commands.SourceExamples,
 		RunE:    r.runE,
+		Deprecated: "this will no longer be available in kustomize v5.\n" +
+			"See discussion in https://github.com/kubernetes-sigs/kustomize/issues/3953.",
 	}
 	runner.FixDocs(name, c)
 	c.Flags().StringVar(&r.WrapKind, "wrap-kind", kio.ResourceListKind,