Extend the cmd with argument handling

- add cobra to relay server
- add logger instance for handshaker

relay/cmd/main.go

@@ -6,13 +6,27 @@ import (
 	"syscall"
 
 	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
 
 	"github.com/netbirdio/netbird/relay/server"
 	"github.com/netbirdio/netbird/util"
 )
 
+var (
+	listenAddress string
+
+	rootCmd = &cobra.Command{
+		Use:   "relay",
+		Short: "Relay service",
+		Long:  "Relay service for Netbird agents",
+		Run:   execute,
+	}
+)
+
 func init() {
-	util.InitLog("trace", "console")
+	_ = util.InitLog("trace", "console")
+	rootCmd.PersistentFlags().StringVarP(&listenAddress, "listen-address", "l", ":1235", "listen address")
+
 }
 
 func waitForExitSignal() {
@@ -21,10 +35,9 @@ func waitForExitSignal() {
 	_ = <-osSigs
 }
 
-func main() {
-	address := "10.145.236.1:1235"
+func execute(cmd *cobra.Command, args []string) {
 	srv := server.NewServer()
-	err := srv.Listen(address)
+	err := srv.Listen(listenAddress)
 	if err != nil {
 		log.Errorf("failed to bind server: %s", err)
 		os.Exit(1)
@@ -38,3 +51,10 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+func main() {
+	err := rootCmd.Execute()
+	if err != nil {
+		os.Exit(1)
+	}
+}