feat(aliases): add aliases for namespaces command

- `namespace`, `ns`, `user`, `users` are aliases for `namespaces`
   command
- `c`, `new` are aliases for the `create` subcommand
- `delete` is an alias for the `destroy` subcommand
- `mv` is an alias for the `rename` subcommand
- `ls`, `show` are aliases for the `list` subcommand

cmd/headscale/cli/namespaces.go

@@ -25,13 +25,15 @@ const (
 )
 
 var namespaceCmd = &cobra.Command{
-	Use:   "namespaces",
-	Short: "Manage the namespaces of Headscale",
+	Use:     "namespaces",
+	Short:   "Manage the namespaces of Headscale",
+	Aliases: []string{"namespace", "ns", "user", "users"},
 }
 
 var createNamespaceCmd = &cobra.Command{
-	Use:   "create NAME",
-	Short: "Creates a new namespace",
+	Use:     "create NAME",
+	Short:   "Creates a new namespace",
+	Aliases: []string{"c", "new"},
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
 			return errMissingParameter
@@ -72,8 +74,9 @@ var createNamespaceCmd = &cobra.Command{
 }
 
 var destroyNamespaceCmd = &cobra.Command{
-	Use:   "destroy NAME",
-	Short: "Destroys a namespace",
+	Use:     "destroy NAME",
+	Short:   "Destroys a namespace",
+	Aliases: []string{"delete"},
 	Args: func(cmd *cobra.Command, args []string) error {
 		if len(args) < 1 {
 			return errMissingParameter
@@ -144,8 +147,9 @@ var destroyNamespaceCmd = &cobra.Command{
 }
 
 var listNamespacesCmd = &cobra.Command{
-	Use:   "list",
-	Short: "List all the namespaces",
+	Use:     "list",
+	Short:   "List all the namespaces",
+	Aliases: []string{"ls", "show"},
 	Run: func(cmd *cobra.Command, args []string) {
 		output, _ := cmd.Flags().GetString("output")
 
@@ -197,8 +201,9 @@ var listNamespacesCmd = &cobra.Command{
 }
 
 var renameNamespaceCmd = &cobra.Command{
-	Use:   "rename OLD_NAME NEW_NAME",
-	Short: "Renames a namespace",
+	Use:     "rename OLD_NAME NEW_NAME",
+	Short:   "Renames a namespace",
+	Aliases: []string{"mv"},
 	Args: func(cmd *cobra.Command, args []string) error {
 		expectedArguments := 2
 		if len(args) < expectedArguments {