add uncloud machine token command to print machine token to add machine to cluster

cmd/uncloud/machine/init.go

@@ -22,7 +22,7 @@ func NewInitCommand() *cobra.Command {
 	opts := initOptions{}
 	cmd := &cobra.Command{
 		Use:   "init",
-		Short: "Initialise a new cluster that consists of the local or remote machine",
+		Short: "Initialise a new cluster that consists of the local or remote machine.",
 		RunE: func(cmd *cobra.Command, args []string) error {
 			netPrefix, err := netip.ParsePrefix(opts.network)
 			if err != nil {

cmd/uncloud/machine/root.go

@@ -12,6 +12,7 @@ func NewRootCommand() *cobra.Command {
 	cmd.AddCommand(
 		NewAddCommand(),
 		NewInitCommand(),
+		NewTokenCommand(),
 	)
 	return cmd
 }

cmd/uncloud/machine/token.go

@@ -0,0 +1,38 @@
+package machine
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+	"uncloud/internal/machine"
+	"uncloud/internal/machine/daemon"
+)
+
+type tokenOptions struct {
+	dataDir string
+}
+
+func NewTokenCommand() *cobra.Command {
+	opts := tokenOptions{}
+	cmd := &cobra.Command{
+		Use:   "token",
+		Short: "Print the local machine's token for adding it to a cluster.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			token, err := daemon.MachineToken(opts.dataDir)
+			if err != nil {
+				return fmt.Errorf("get machine token: %w", err)
+			}
+			tokenStr, err := token.String()
+			if err != nil {
+				return fmt.Errorf("encode machine token: %w", err)
+			}
+			fmt.Println(tokenStr)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVarP(&opts.dataDir, "data-dir", "d", machine.DefaultDataDir,
+		"Directory for storing persistent machine state")
+	_ = cmd.MarkFlagDirname("data-dir")
+
+	return cmd
+}