Added some Cobra framework for new command groups as I'm thinking through the interface.

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

@@ -0,0 +1,32 @@
+package list
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+)
+
+var (
+	listCmd = &cobra.Command{
+		Use:                "list",
+		Short:              "List Warewulf Overlays",
+		Long:               "Warewulf List overlay",
+		RunE:				CobraRunE,
+	}
+
+)
+
+func init() {
+
+}
+
+// GetRootCommand returns the root cobra.Command for the application.
+func GetCommand() *cobra.Command {
+	return listCmd
+}
+
+
+func CobraRunE(cmd *cobra.Command, args []string) error {
+
+	fmt.Printf("List: Hello World\n")
+	return nil
+}

internal/app/wwctl/overlay/root.go

@@ -0,0 +1,30 @@
+package overlay
+
+import (
+	"github.com/hpcng/warewulf/internal/app/wwctl/overlay/list"
+	"github.com/hpcng/warewulf/internal/app/wwctl/overlay/show"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	overlayCmd = &cobra.Command{
+		Use:                "overlay",
+		Short:              "Warewulf Overlay Management",
+		Long:               "Management interface for Warewulf overlays",
+	}
+	test bool
+)
+
+func init() {
+	overlayCmd.PersistentFlags().BoolVarP(&test, "test", "t", false, "Testing.")
+
+	overlayCmd.AddCommand(list.GetCommand())
+	overlayCmd.AddCommand(show.GetCommand())
+
+}
+
+// GetRootCommand returns the root cobra.Command for the application.
+func GetCommand() *cobra.Command {
+	return overlayCmd
+}

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

@@ -0,0 +1,32 @@
+package show
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+)
+
+var (
+	showCmd = &cobra.Command{
+		Use:                "show",
+		Short:              "Show Warewulf Overlay objects",
+		Long:               "Warewulf show overlay objects",
+		RunE:				CobraRunE,
+	}
+
+)
+
+func init() {
+
+}
+
+// GetRootCommand returns the root cobra.Command for the application.
+func GetCommand() *cobra.Command {
+	return showCmd
+}
+
+
+func CobraRunE(cmd *cobra.Command, args []string) error {
+
+	fmt.Printf("Show: Hello World\n")
+	return nil
+}

internal/app/wwctl/root.go

@@ -2,6 +2,7 @@ package wwctl
 
 import (
 	"github.com/hpcng/warewulf/internal/app/wwctl/build"
+	"github.com/hpcng/warewulf/internal/app/wwctl/overlay"
 	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 	"github.com/spf13/cobra"
 )
@@ -22,6 +23,7 @@ func init() {
 	rootCmd.PersistentFlags().BoolVarP(&debugArg, "debug", "d", false, "Run with debugging messages enabled.")
 
 	rootCmd.AddCommand(build.GetCommand())
+	rootCmd.AddCommand(overlay.GetCommand())
 }
 
 // GetRootCommand returns the root cobra.Command for the application.