Load DERP servers from file

cmd/headscale/headscale.go

@@ -1,10 +1,14 @@
 package main
 
 import (
+	"io"
 	"log"
+	"os"
 
 	"github.com/juanfont/headscale"
 	"github.com/spf13/viper"
+	"gopkg.in/yaml.v2"
+	"tailscale.com/tailcfg"
 )
 
 func main() {
@@ -16,10 +20,16 @@ func main() {
 		log.Fatalf("Fatal error config file: %s \n", err)
 	}
 
+	derpMap, err := loadDerpMap(viper.GetString("derp_map_path"))
+	if err != nil {
+		log.Printf("Could not load DERP servers map file: %s", err)
+	}
+
 	cfg := headscale.Config{
 		ServerURL:      viper.GetString("server_url"),
 		Addr:           viper.GetString("listen_addr"),
 		PrivateKeyPath: viper.GetString("private_key_path"),
+		DerpMap:        derpMap,
 
 		DBhost: viper.GetString("db_host"),
 		DBport: viper.GetInt("db_port"),
@@ -33,3 +43,18 @@ func main() {
 	}
 	h.Serve()
 }
+
+func loadDerpMap(path string) (*tailcfg.DERPMap, error) {
+	derpFile, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer derpFile.Close()
+	var derpMap tailcfg.DERPMap
+	b, err := io.ReadAll(derpFile)
+	if err != nil {
+		return nil, err
+	}
+	err = yaml.Unmarshal(b, &derpMap)
+	return &derpMap, err
+}