headscale now has a CLI - registration of machines occurs there

app.go

@@ -3,6 +3,7 @@ package headscale
 import (
 	"fmt"
 	"io/ioutil"
+	"log"
 
 	"github.com/gin-gonic/gin"
 	"tailscale.com/tailcfg"
@@ -65,3 +66,38 @@ func (h *Headscale) Serve() error {
 	err := r.Run(h.cfg.Addr)
 	return err
 }
+
+func (h *Headscale) RegisterMachine(key string) error {
+	mKey, err := wgcfg.ParseHexKey(key)
+	if err != nil {
+		log.Printf("Cannot parse client key: %s", err)
+		return err
+	}
+	db, err := h.db()
+	if err != nil {
+		log.Printf("Cannot open DB: %s", err)
+		return err
+	}
+	defer db.Close()
+	m := Machine{}
+	if db.First(&m, "machine_key = ?", mKey.HexString()).RecordNotFound() {
+		log.Printf("Cannot find machine with machine key: %s", mKey.Base64())
+		return err
+	}
+
+	if m.isAlreadyRegistered() {
+		fmt.Println("This machine already registered")
+		return nil
+	}
+
+	ip, err := h.getAvailableIP()
+	if err != nil {
+		log.Println(err)
+		return err
+	}
+	m.IPAddress = ip.String()
+	m.Registered = true
+	db.Save(&m)
+	fmt.Println("Machine registered 🎉")
+	return nil
+}