refactor go-flags initialization

main.go

@@ -4,29 +4,22 @@ import (
 	"os"
 
 	goflags "github.com/jessevdk/go-flags"
+
 	"github.com/motiejus/code/undocker/internal/cmdlxcconfig"
 	"github.com/motiejus/code/undocker/internal/cmdrootfs"
 )
 
-type (
-	params struct {
-		RootFS    cmdrootfs.Command    `command:"rootfs" description:"Unpack a docker container image to a single filesystem tarball"`
-		LXCConfig cmdlxcconfig.Command `command:"lxcconfig" description:"Create an LXC-compatible container configuration"`
-	}
-)
-
 func main() {
-	if err := run(os.Args); err != nil {
+	flags := goflags.NewParser(nil, goflags.Default)
+
+	rootfs := cmdrootfs.NewCommand()
+	lxcconfig := cmdlxcconfig.NewCommand()
+	flags.AddCommand("rootfs", rootfs.ShortDesc(), rootfs.LongDesc(), rootfs)
+	flags.AddCommand("lxcconfig", lxcconfig.ShortDesc(), lxcconfig.LongDesc(), lxcconfig)
+
+	_, err := flags.Parse()
+	if err != nil {
 		os.Exit(1)
 	}
 	os.Exit(0)
 }
-
-func run(args []string) error {
-	var opts params
-	if _, err := goflags.ParseArgs(&opts, args[1:]); err != nil {
-		return err
-	}
-
-	return nil
-}