cleanup code warnings, update RaspberryPi readme

internal/server/server.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"encoding/gob"
 	"html/template"
+	"io"
 	"io/fs"
-	"io/ioutil"
 	"math/rand"
 	"net/http"
 	"net/url"
@@ -110,7 +110,7 @@ func (s *Server) Setup(ctx context.Context) error {
 
 	// Setup http server
 	gin.SetMode(gin.DebugMode)
-	gin.DefaultWriter = ioutil.Discard
+	gin.DefaultWriter = io.Discard
 	s.server = gin.New()
 	if logrus.GetLevel() == logrus.TraceLevel {
 		s.server.Use(ginlogrus.Logger(logrus.StandardLogger()))

internal/server/server_helper.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"crypto/md5"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path"
 	"syscall"
 	"time"
@@ -224,7 +224,7 @@ func (s *Server) WriteWireGuardConfigFile(device string) error {
 		return errors.WithMessage(err, "failed to get config file")
 	}
 	filePath := path.Join(s.config.WG.ConfigDirectoryPath, dev.DeviceName+".conf")
-	if err := ioutil.WriteFile(filePath, cfg, 0644); err != nil {
+	if err := os.WriteFile(filePath, cfg, 0644); err != nil {
 		return errors.Wrap(err, "failed to write WireGuard config file")
 	}
 	return nil