fix(dashboard): fix nit codes

apps/emqx_dashboard/i18n/emqx_dashboard_i18n.conf

@@ -203,8 +203,19 @@ its own from which a browser should permit loading resources."""
       zh: "初始化用户文件"
     }
     label {
-      en: "Initialize users file"
+      en: """Is used to add an administrative user to Dashboard when emqx is first launched,
-      zh: "初始化用户文件"
+      the format is:
+       ```
+       username1:password1
+       username2:password2
+       ```
+"""
+      zh: """用于在首次启动 emqx 时，为 Dashboard 添加管理用户，其格式为：
+      ```
+      username1:password1
+      username2:password2
+      ```
+"""
     }
   }
 }

apps/emqx_dashboard/src/emqx_dashboard_admin.erl

@@ -19,6 +19,7 @@
 -module(emqx_dashboard_admin).
 
 -include("emqx_dashboard.hrl").
+-include_lib("emqx/include/logger.hrl").
 -include_lib("stdlib/include/ms_transform.hrl").
 
 -boot_mnesia({mnesia, [boot]}).
@@ -91,6 +92,7 @@ add_bootstrap_user() ->
         File ->
             case mnesia:table_info(?ADMIN, size) of
                 0 ->
+                    ?SLOG(debug, #{msg => "Add dashboard bootstrap users", file => File}),
                     add_bootstrap_user(File);
                 _ ->
                     ok

apps/emqx_dashboard/src/emqx_dashboard_app.erl

@@ -31,9 +31,13 @@ start(_StartType, _StartArgs) ->
     case emqx_dashboard:start_listeners() of
         ok ->
             emqx_dashboard_cli:load(),
-            ok = emqx_dashboard_admin:add_bootstrap_user(),
+            case emqx_dashboard_admin:add_bootstrap_user() of
+                ok ->
                     {ok, _} = emqx_dashboard_admin:add_default_user(),
                     {ok, Sup};
+                Error ->
+                    Error
+            end;
         {error, Reason} ->
             {error, Reason}
     end.