[VOL-2760] Disable the clearing of the global log level setting

Change-Id: I26c35fa449126b036ddbb71db82d6da17b467b08
diff --git a/internal/pkg/commands/loglevel.go b/internal/pkg/commands/loglevel.go
index 2bdd5cf..acdc115 100644
--- a/internal/pkg/commands/loglevel.go
+++ b/internal/pkg/commands/loglevel.go
@@ -103,6 +103,11 @@
 	for _, component := range Components {
 		logConfig := model.LogLevel{}
 		val := strings.SplitN(component, "#", 2)
+
+		if strings.Contains(val[0], "/") {
+			return nil, errors.New("the component name '" + val[0] + "' contains an invalid character '/'")
+		}
+
 		if len(val) > 1 {
 			if val[0] == defaultComponentName {
 				return nil, errors.New("global level doesn't support packageName")
@@ -162,7 +167,7 @@
 
 	if options.Args.Level != "" {
 		if _, err := log.StringToLogLevel(options.Args.Level); err != nil {
-			return fmt.Errorf("Unknown log level %s. Allowed values are INFO, DEBUG, ERROR, WARN, FATAL", options.Args.Level)
+			return fmt.Errorf("Unknown log level '%s'. Allowed values are  DEBUG, INFO, WARN, ERROR, FATAL", options.Args.Level)
 		}
 	}
 
@@ -384,6 +389,10 @@
 
 	for _, lConfig := range logLevelConfig {
 
+		if lConfig.ComponentName == defaultComponentName {
+			return fmt.Errorf("The global default loglevel cannot be cleared.")
+		}
+
 		logConfig := cm.InitComponentConfig(lConfig.ComponentName, config.ConfigTypeLogLevel)
 
 		err := logConfig.Delete(ctx, lConfig.PackageName)