Fleshed out the framework of most of the wwctl overlay command group.

internal/app/wwctl/overlay/mkdir/root.go

@@ -0,0 +1,28 @@
+package mkdir
+
+import (
+	"github.com/spf13/cobra"
+)
+
+var (
+	baseCmd = &cobra.Command{
+		Use:                "mkdir [overlay name] [directory path]",
+		Short:              "Create a new directory",
+		Long:               "Create a new directory within a Warewulf overlay",
+		RunE:				CobraRunE,
+		Args: 				cobra.MinimumNArgs(2),
+	}
+	SystemOverlay bool
+//	PermMode os.FileMode
+)
+
+func init() {
+	baseCmd.PersistentFlags().BoolVarP(&SystemOverlay, "system", "s", false, "Show System Overlays as well")
+	// This will be added back as soon as I figure out how to properly handle the FileMode case
+//	baseCmd.PersistentFlags().Uint32VarP(&PermMode, "mode", "m", 0755, "Permission mode for directory")
+}
+
+// GetRootCommand returns the root cobra.Command for the application.
+func GetCommand() *cobra.Command {
+	return baseCmd
+}