diff --git a/server/cli/cli.go b/server/cli/cli.go
index 619764a..655ca43 100644
--- a/server/cli/cli.go
+++ b/server/cli/cli.go
@@ -4,12 +4,13 @@ import (
 	"context"
 	"crypto/md5"
 	"fmt"
-	"next-terminal/server/env"
-	"next-terminal/server/service"
 
+	"next-terminal/server/constant"
+	"next-terminal/server/env"
 	"next-terminal/server/log"
 	"next-terminal/server/model"
 	"next-terminal/server/repository"
+	"next-terminal/server/service"
 	"next-terminal/server/utils"
 
 	"gorm.io/gorm"
@@ -65,7 +66,7 @@ func (cli Cli) ChangeEncryptionKey(oldEncryptionKey, newEncryptionKey string) er
 	newPassword := []byte(fmt.Sprintf("%x", md5.Sum([]byte(newEncryptionKey))))
 
 	return env.GetDB().Transaction(func(tx *gorm.DB) error {
-		c := context.WithValue(context.TODO(), "db", tx)
+		c := context.WithValue(context.TODO(), constant.DB, tx)
 		credentials, err := repository.CredentialRepository.FindAll(c)
 		if err != nil {
 			return err
diff --git a/server/constant/const.go b/server/constant/const.go
index 00281e3..0f05c2a 100644
--- a/server/constant/const.go
+++ b/server/constant/const.go
@@ -19,8 +19,10 @@ const (
 
 const Token = "X-Auth-Token"
 
+type Key string
+
 const (
-	DB = "db"
+	DB Key = "db"
 
 	SSH    = "ssh"
 	RDP    = "rdp"
diff --git a/server/service/backup.go b/server/service/backup.go
index 4b6ca5b..3eef961 100644
--- a/server/service/backup.go
+++ b/server/service/backup.go
@@ -220,7 +220,7 @@ func (service backupService) Import(backup *dto.Backup) error {
 			}
 		}
 
-		var accessGatewayIdMapping = make(map[string]string, 0)
+		var accessGatewayIdMapping = make(map[string]string)
 		if len(backup.AccessGateways) > 0 {
 			for _, item := range backup.AccessGateways {
 				oldId := item.ID
@@ -244,7 +244,7 @@ func (service backupService) Import(backup *dto.Backup) error {
 			}
 		}
 
-		var credentialIdMapping = make(map[string]string, 0)
+		var credentialIdMapping = make(map[string]string)
 		if len(backup.Credentials) > 0 {
 			for _, item := range backup.Credentials {
 				oldId := item.ID
@@ -257,7 +257,7 @@ func (service backupService) Import(backup *dto.Backup) error {
 			}
 		}
 
-		var assetIdMapping = make(map[string]string, 0)
+		var assetIdMapping = make(map[string]string)
 		if len(backup.Assets) > 0 {
 			for _, m := range backup.Assets {
 				data, err := json.Marshal(m)
diff --git a/server/service/user.go b/server/service/user.go
index 2028cce..b63863e 100644
--- a/server/service/user.go
+++ b/server/service/user.go
@@ -3,6 +3,7 @@ package service
 import (
 	"errors"
 	"fmt"
+	"strings"
 
 	"next-terminal/server/constant"
 	"next-terminal/server/dto"
@@ -12,7 +13,6 @@ import (
 	"next-terminal/server/model"
 	"next-terminal/server/repository"
 	"next-terminal/server/utils"
-	"strings"
 
 	"golang.org/x/net/context"
 	"gorm.io/gorm"
diff --git a/server/sshd/ui.go b/server/sshd/ui.go
index d87f296..a59cc35 100644
--- a/server/sshd/ui.go
+++ b/server/sshd/ui.go
@@ -5,6 +5,9 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"path"
+	"strings"
+
 	"next-terminal/server/api"
 	"next-terminal/server/config"
 	"next-terminal/server/constant"
@@ -18,8 +21,6 @@ import (
 	"next-terminal/server/term"
 	"next-terminal/server/totp"
 	"next-terminal/server/utils"
-	"path"
-	"strings"
 
 	"github.com/gliderlabs/ssh"
 	"github.com/manifoldco/promptui"
diff --git a/server/term/next_terminal.go b/server/term/next_terminal.go
index 3be9d44..2029fdc 100644
--- a/server/term/next_terminal.go
+++ b/server/term/next_terminal.go
@@ -22,7 +22,7 @@ func NewNextTerminal(ip string, port int, username, password, privateKey, passph
 	if err != nil {
 		return nil, err
 	}
-	return newNT(err, sshClient, pipe, recording, term, rows, cols)
+	return newNT(sshClient, pipe, recording, term, rows, cols)
 }
 
 func NewNextTerminalUseSocks(ip string, port int, username, password, privateKey, passphrase string, rows, cols int, recording, term string, pipe bool, socksProxyHost, socksProxyPort, socksProxyUsername, socksProxyPassword string) (*NextTerminal, error) {
@@ -30,10 +30,10 @@ func NewNextTerminalUseSocks(ip string, port int, username, password, privateKey
 	if err != nil {
 		return nil, err
 	}
-	return newNT(err, sshClient, pipe, recording, term, rows, cols)
+	return newNT(sshClient, pipe, recording, term, rows, cols)
 }
 
-func newNT(err error, sshClient *ssh.Client, pipe bool, recording string, term string, rows int, cols int) (*NextTerminal, error) {
+func newNT(sshClient *ssh.Client, pipe bool, recording string, term string, rows int, cols int) (*NextTerminal, error) {
 	sshSession, err := sshClient.NewSession()
 	if err != nil {
 		return nil, err
diff --git a/server/utils/guacamole.go b/server/utils/guacamole.go
index 3173ce9..dc917cd 100644
--- a/server/utils/guacamole.go
+++ b/server/utils/guacamole.go
@@ -2,9 +2,11 @@ package utils
 
 import (
 	"encoding/base64"
-	"github.com/gorilla/websocket"
-	"next-terminal/server/guacd"
 	"strconv"
+
+	"next-terminal/server/guacd"
+
+	"github.com/gorilla/websocket"
 )
 
 func Disconnect(ws *websocket.Conn, code int, reason string) {