Reworked nexus-exam to better indicate whether there is a connection issue

Makefile

@@ -312,7 +312,7 @@ build_nexus-exam: check_server_var check_cert_var check_nexus_exam_vars copy_res
 	@echo -n '$(value EXAM_PWD)' > $(NEXUS_EXAM_PWD_CREDS_FILE)
 	@cd $(SRC_CLIENT)/nexus-exam && go build $(BUILD_FLAGS) $(BUILD_CLIENT_FLAGS) && mv nexus-exam $(BUILD_ABS_CLIENT)
 	@strip -s $(BUILD_DIR_CLIENT)/nexus-exam
-	@upx -q $(BUILD_DIR_CLIENT)/nexus-exam
+#	@upx -q $(BUILD_DIR_CLIENT)/nexus-exam
 	@rm $(NEXUS_EXAM_USER_CREDS_FILE) $(NEXUS_EXAM_PWD_CREDS_FILE)
 
 clean_client:

src/client/nexus-exam/nexus-exam.go

@@ -32,6 +32,8 @@ import (
 
 const (
 	windowTitle = "nexus-exam"
+
+	connectionMsg = "Enter password to connect to your VM:"
 )
 
 var (
@@ -41,9 +43,13 @@ var (
 	//go:embed nexus_exam_pwd.val
 	nexus_exam_pwd string
 
-	token    string
-	certPath string
 	exitFn func()
+
+	token string
+
+	loggedIn   bool
+	appLabel   *widget.Label
+	appConnect *widget.Form
 )
 
 func exit(code int) {
@@ -144,27 +150,44 @@ func setHeaderToken() {
 
 // Recurrently obtains a new JWT token so that the user session doesn't expire.
 func refreshToken(parent fyne.Window) {
-	// Wait 10 seconds before attempting to refresh the token.
-	// The reason for this delay is that when nexus-exam is launched from
-	// a nexus live image, the wifi interface might not be up yet.
-	time.Sleep(10 * time.Second)
+	var err error
 
 	for {
+		if !loggedIn {
+			// Logins and obtains a JWT token.
+			token, err = cmdLogin.GetToken(nexus_exam_user, nexus_exam_pwd)
+			if err != nil {
+				appLabel.SetText("Unable to connect to server (error code 1)...\nCheck your network connection.")
+				u.PrintlnErr(time.Now(), ": failed connecting to server: "+err.Error())
+			} else {
+				u.Println(time.Now(), ": successfully connected to server")
+				appLabel.SetText(connectionMsg)
+				loggedIn = true
+			}
+		} else {
 			setHeaderToken()
 			refreshedToken, err := cmdToken.GetToken()
 			if err != nil {
-			errorPopup(parent, "Failed refreshing token")
+				appLabel.SetText("Unable to connect to server (error code 2)...\nCheck your network connection.")
 				u.PrintlnErr(time.Now(), ": failed refreshing token: "+err.Error())
-			break
+				loggedIn = false
 			} else {
+				appLabel.SetText(connectionMsg)
 				u.Println(time.Now(), ": successfully refreshed token")
 			}
 			token = refreshedToken
-		time.Sleep(1 * time.Hour)
+		}
+		if loggedIn {
+			appConnect.Show()
+		} else {
+			appConnect.Hide()
+		}
+		time.Sleep(10 * time.Second)
 	}
 }
 
 func run() int {
+	loggedIn = false
 	var appname = path.Base(os.Args[0])
 	clientVersion := version.Get()
 	u.PrintlnErr(appname + " version " + clientVersion.String() + " (commit " + buildversion.GitCommit() + ")")
@@ -176,11 +199,9 @@ func run() int {
 		abortWindow(err.Error())
 	}
 
-	var err error // necessary for certPath below to be ref as the same variable
-
-	certPath, err = defaults.CreateCert()
+	certPath, err := defaults.CreateCert()
 	if err != nil {
-		abortWindow("Failed creating certificate from embedded certificate!")
+		abortWindow("Failed creating certificate!")
 	}
 	// No embedded certificate, exit with a information message.
 	if certPath == "" {
@@ -205,19 +226,13 @@ func run() int {
 
 	g.Init(hostname, host, certPath, client)
 
-	client.SetTimeout(10 * time.Second)
+	client.SetTimeout(4 * time.Second)
 
 	// Checks the client version is compatible with the server's API.
 	// if !cmdVersion.CheckServerCompatibility("nexus-exam") {
 	//     abortWindow("client version is incompatible with server!")
 	// }
 
-	// Logins and obtains a JWT token.
-	token, err = cmdLogin.GetToken(nexus_exam_user, nexus_exam_pwd)
-	if err != nil {
-		abortWindow("Failed obtaining token (network issue?)")
-	}
-
 	app := app.New()
 	app.Settings().SetTheme(theme.LightTheme())
 	win := app.NewWindow(windowTitle)
@@ -232,9 +247,9 @@ func run() int {
 		return nil
 	}
 
-	label := widget.NewLabel("Enter password to connect to your VM:")
+	appLabel = widget.NewLabel("Please wait, connecting to server...")
 
-	form := &widget.Form{
+	appConnect = &widget.Form{
 		Items: []*widget.FormItem{
 			{Text: "Password", Widget: pwdEntry},
 		},
@@ -244,8 +259,9 @@ func run() int {
 		SubmitText: "Connect",
 	}
 
-	win.SetContent(container.NewPadded(container.NewVBox(label, form)))
-	win.Resize(fyne.NewSize(600, 200))
+	win.SetContent(container.NewPadded(container.NewVBox(appLabel, appConnect)))
+	win.Resize(fyne.NewSize(600, 160))
+	appConnect.Hide()
 
 	go refreshToken(win)