allow kubectl cmd to process dirs recursively

reqs:
    - the kubectl cmd must support the -f | --filename flag
    - the kubectl cmd must support visiting a dir one level deep,
    or using more than one resource

pkg/kubectl/cmd/label.go

@@ -39,6 +39,7 @@ import (
 // referencing the cmd.Flags()
 type LabelOptions struct {
 	Filenames []string
+	Recursive bool
 }
 
 const (
@@ -96,6 +97,7 @@ func NewCmdLabel(f *cmdutil.Factory, out io.Writer) *cobra.Command {
 	cmd.Flags().String("resource-version", "", "If non-empty, the labels update will only succeed if this is the current resource-version for the object. Only valid when specifying a single resource.")
 	usage := "Filename, directory, or URL to a file identifying the resource to update the labels"
 	kubectl.AddJsonFilenameFlag(cmd, &options.Filenames, usage)
+	cmdutil.AddRecursiveFlag(cmd, &options.Recursive)
 	cmd.Flags().Bool("dry-run", false, "If true, only print the object that would be sent, without sending it.")
 	cmdutil.AddRecordFlag(cmd)
 
@@ -203,10 +205,11 @@ func RunLabel(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []stri
 		return cmdutil.UsageError(cmd, err.Error())
 	}
 	mapper, typer := f.Object()
+
 	b := resource.NewBuilder(mapper, typer, resource.ClientMapperFunc(f.ClientForMapping), f.Decoder(true)).
 		ContinueOnError().
 		NamespaceParam(cmdNamespace).DefaultNamespace().
-		FilenameParam(enforceNamespace, options.Filenames...).
+		FilenameParam(enforceNamespace, options.Recursive, options.Filenames...).
 		SelectorParam(selector).
 		ResourceTypeOrNameArgs(all, resources...).
 		Flatten().