Core of image's duplication feature

internal/app/wwctl/container/copy/root.go

@@ -0,0 +1,33 @@
+package copy
+
+import (
+	"github.com/hpcng/warewulf/internal/pkg/container"
+	"github.com/spf13/cobra"
+)
+
+var (
+	baseCmd = &cobra.Command{
+		DisableFlagsInUseLine: true,
+		Use:                   "cp CONTAINER NEW_NAME",
+		Short:                 "Copy an existing container",
+		Long:                  "This command will duplicate an imported container image.",
+		RunE:                  CobraRunE,
+		Args:                  cobra.MinimumNArgs(2),
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) != 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			list, _ := container.ListSources()
+			return list, cobra.ShellCompDirectiveNoFileComp
+		},
+	}
+)
+
+func init() {
+	// Nothing to do here
+}
+
+// GetRootCommand returns the root cobra.Command for the application.
+func GetCommand() *cobra.Command {
+	return baseCmd
+}