Raise error when adding a new zot config with an existed saved name

pkg/cli/config_cmd.go

@@ -204,6 +204,10 @@ func addConfig(configPath, configName, url string) error {
 		return zotErrors.ErrInvalidURL
 	}
 
+	if configNameExists(configs, configName) {
+		return zotErrors.ErrDuplicateConfigName
+	}
+
 	configMap := make(map[string]interface{})
 	configMap["url"] = url
 	configMap[nameKey] = configName
@@ -361,6 +365,17 @@ func getAllConfig(configPath, configName string) (string, error) {
 	return "", zotErrors.ErrConfigNotFound
 }
 
+func configNameExists(configs []interface{}, configName string) bool {
+	for _, val := range configs {
+		configMap := val.(map[string]interface{})
+		if configMap[nameKey] == configName {
+			return true
+		}
+	}
+
+	return false
+}
+
 const (
 	examples = `  zot config add main https://zot-foo.com:8080
   zot config main url