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

internal/machine/daemon/token.go

@@ -0,0 +1,41 @@
+package daemon
+
+import (
+	"errors"
+	"fmt"
+	"net/netip"
+	"os"
+	"uncloud/internal/machine"
+	"uncloud/internal/machine/network"
+)
+
+// MachineToken returns the local machine's token that can be used for adding the machine to a cluster.
+// TODO: ideally, this should be an RPC call to the daemon API to ensure the config is created and up-to-date.
+func MachineToken(dataDir string) (machine.Token, error) {
+	cfg, err := machine.ParseConfig(machine.ConfigPath(dataDir))
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return machine.Token{}, fmt.Errorf("load machine config (is uncloudd daemon running?): %w", err)
+		}
+		return machine.Token{}, fmt.Errorf("load machine config: %w", err)
+	}
+	if len(cfg.Network.PublicKey) == 0 {
+		return machine.Token{}, errors.New("public key is not set in machine config")
+	}
+
+	ips, err := network.ListRoutableIPs()
+	if err != nil {
+		return machine.Token{}, fmt.Errorf("list routable addresses: %w", err)
+	}
+	publicIP, err := network.GetPublicIP()
+	// Ignore the error if failed to get the public IP using API services.
+	if err == nil {
+		ips = append([]netip.Addr{publicIP}, ips...)
+	}
+
+	endpoints := make([]netip.AddrPort, len(ips))
+	for i, ip := range ips {
+		endpoints[i] = netip.AddrPortFrom(ip, network.WireGuardPort)
+	}
+	return machine.NewToken(cfg.Network.PublicKey, endpoints), nil
+}