From 1a715c8708a3029cf559498ab2adc65197c2a3ae Mon Sep 17 00:00:00 2001
From: Georgy Sychev <georgy.sychev@emqx.io>
Date: Thu, 17 Feb 2022 22:49:48 +0300
Subject: [PATCH 1/7] feat(emqx_dashboard): subsciption to update password
 emqx_dashboard restarted in ekka hook Closes #3155

---
 CHANGES-4.3.md                                |   1 +
 .../src/emqx_rule_engine.appup.src            |  12 +-
 .../src/emqx_dashboard_admin.erl              |  83 ++++----
 .../test/emqx_dashboard_SUITE.erl             | 149 ++++++++++++-
 src/emqx.appup.src                            | 200 ++++++------------
 src/emqx.erl                                  |  14 +-
 6 files changed, 273 insertions(+), 186 deletions(-)

diff --git a/CHANGES-4.3.md b/CHANGES-4.3.md
index bb33daaba..77617a60c 100644
--- a/CHANGES-4.3.md
+++ b/CHANGES-4.3.md
@@ -25,6 +25,7 @@ File format:
 * Prohibit empty topics in strict mode
 * Make sure ehttpc delete useless pool always succeed.
 * Update mongodb driver to fix potential process leak.
+* Dashboard admin password persists after leaving/joining the cluster
 
 ## v4.3.13
 
diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
index e151086be..f47cff1f9 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
@@ -4,12 +4,12 @@
   [{"4.3.8",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
-     {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
-     {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_events,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
-     {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]}]},
    {"4.3.7",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
@@ -101,12 +101,12 @@
   [{"4.3.8",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
-     {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_metrics,brutal_purge,soft_purge,[]},
-     {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_events,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
-     {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]}]},
    {"4.3.7",
     [{load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
diff --git a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
index 420380f88..505c468cd 100644
--- a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
+++ b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
@@ -21,7 +21,6 @@
 -behaviour(gen_server).
 
 -include("emqx_dashboard.hrl").
--include_lib("emqx/include/logger.hrl").
 
 -boot_mnesia({mnesia, [boot]}).
 -copy_mnesia({mnesia, [copy]}).
@@ -146,9 +145,9 @@ update_pwd(Username, Fun) ->
     Trans = fun() ->
                     User =
                     case lookup_user(Username) of
-                    [Admin] -> Admin;
-                    [] ->
-                           mnesia:abort(<<"Username Not Found">>)
+                        [Admin] -> Admin;
+                        [] ->
+                            mnesia:abort(<<"Username Not Found">>)
                     end,
                     mnesia:write(Fun(User))
             end,
@@ -156,7 +155,14 @@ update_pwd(Username, Fun) ->
 
 
 -spec(lookup_user(binary()) -> [mqtt_admin()]).
-lookup_user(Username) when is_binary(Username) -> mnesia:dirty_read(mqtt_admin, Username).
+lookup_user(Username) when is_binary(Username) ->
+    case binenv(default_user_username) of
+        Username ->
+            Password = hashed_default_passwd(),
+            [#mqtt_admin{username=Username, password=Password, tags= <<"administrator">>}];
+        _ ->
+            mnesia:dirty_read(mqtt_admin, Username)
+    end.
 
 -spec(all_users() -> [#mqtt_admin{}]).
 all_users() -> ets:tab2list(mqtt_admin).
@@ -187,7 +193,8 @@ check(Username, Password) ->
 
 init([]) ->
     %% Add default admin user
-    _ = add_default_user(binenv(default_user_username), binenv(default_user_passwd)),
+    {ok, _} = mnesia:subscribe({table, mqtt_admin, simple}),
+    add_default_user_hashed(binenv(default_user_username), hashed_default_passwd()),
     {ok, state}.
 
 handle_call(_Req, _From, State) ->
@@ -196,6 +203,17 @@ handle_call(_Req, _From, State) ->
 handle_cast(_Msg, State) ->
     {noreply, State}.
 
+handle_info({mnesia_table_event, {write, Admin, _}}, State) ->
+    #mqtt_admin{username=Username, password=HashedPassword} = Admin,
+    case binenv(default_user_username) of
+        Username ->
+            application:set_env(emqx_dashboard, default_user_passwd_hashed, HashedPassword);
+
+        _ ->
+            ignore
+    end,
+    {noreply, State};
+
 handle_info(_Msg, State) ->
     {noreply, State}.
 
@@ -222,37 +240,26 @@ salt() ->
     <<Salt:32>>.
 
 binenv(Key) ->
-    iolist_to_binary(application:get_env(emqx_dashboard, Key, "")).
+    iolist_to_binary(application:get_env(emqx_dashboard, Key, <<>>)).
 
-add_default_user(Username, Password) when ?EMPTY_KEY(Username) orelse ?EMPTY_KEY(Password) ->
-    ignore;
+add_default_user_hashed(Username, HashedPassword) ->
+    case mnesia:dirty_read(mqtt_admin, Username) of
+        [] ->
+            Admin = #mqtt_admin{username=Username, password=HashedPassword, tags= <<"administrator">>},
+            return(mnesia:transaction(fun add_user_/1, [Admin]));
+        _  -> ok
+    end.
 
-add_default_user(Username, Password) ->
-    case lookup_user(Username) of
-        [] -> add_user(Username, Password, <<"administrator">>);
-        _  ->
-            case check(Username, Password) of
-                ok ->
-                    ?LOG(warning,
-                        "[Dashboard] The initial default password for dashboard 'admin' user in emqx_dashboard.conf\n"
-                        "For safety, it should be changed as soon as possible.\n"
-                        "Please use the './bin/emqx_ctl admins' CLI to change it.\n"
-                        "Then remove `dashboard.default_user.login/password` from emqx_dashboard.conf"
-                    );
-                {error, _} ->
-                    %% We can't force add default,
-                    %% otherwise passwords that have been updated via HTTP API will be reset after reboot.
-                    ?LOG(warning,
-                        "[Dashboard] dashboard.default_user.password in the plugins/emqx_dashboard.conf\n"
-                        "does not match the password in the database(mnesia).\n"
-                        "1. If you have already changed the password via the HTTP API or `./bin/emqx_ctl admins`,"
-                        "this warning has no effect.\n"
-                        "You should remove the `dashboard.default_user.login/password` from emqx_dashboard.conf "
-                        "to resolve this warning.\n"
-                        "2. If you just want to update the password by manually changing the configuration file,\n"
-                        "you need to delete the old user and password using `emqx_ctl admins del ~s` first\n"
-                        "the new password in emqx_dashboard.conf can take effect after reboot.",
-                        [])
-            end
-    end,
-    ok.
+hashed_default_passwd() ->
+    case binenv(default_user_passwd_hashed) of
+        Empty0 when ?EMPTY_KEY(Empty0) ->
+            case binenv(default_user_passwd) of
+                Empty when ?EMPTY_KEY(Empty) ->
+                    undefined;
+                Password ->
+                    Hashed = hash(Password),
+                    application:set_env(emqx_dashboard, default_user_passwd_hashed, Hashed),
+                    Hashed
+            end;
+        HashedPassword -> HashedPassword
+    end.
diff --git a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
index 5099d4449..28d80ae7d 100644
--- a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
+++ b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
@@ -29,6 +29,8 @@
 
 -include_lib("emqx/include/emqx.hrl").
 
+-include("emqx_dashboard.hrl").
+
 -define(CONTENT_TYPE, "application/x-www-form-urlencoded").
 
 -define(HOST, "http://127.0.0.1:18083/").
@@ -40,21 +42,23 @@
 -define(OVERVIEWS, ['alarms/activated', 'alarms/deactivated', banned, brokers, stats, metrics, listeners, clients, subscriptions, routes, plugins]).
 
 all() ->
-    [{group, overview},
+    [
+     {group, overview},
      {group, admins},
      {group, rest},
      {group, cli}
      ].
 
 groups() ->
-    [{overview, [sequence], [t_overview]},
-     {admins, [sequence], [t_admins_add_delete]},
-     {rest, [sequence], [t_rest_api, t_auth_exhaustive_attack]},
+    [
+     {overview, [sequence], [t_overview]},
+     {admins, [sequence], [t_admins_add_delete, t_admins_persist_default_password, t_default_password_persists_after_leaving_cluster]},
+     {rest, [sequence], [t_rest_api]},
      {cli, [sequence], [t_cli]}
     ].
 
 init_per_suite(Config) ->
-    emqx_ct_helpers:start_apps([emqx_modules, emqx_management, emqx_dashboard]),
+    ok = emqx_ct_helpers:start_apps([emqx_modules, emqx_management, emqx_dashboard]),
     Config.
 
 end_per_suite(_Config) ->
@@ -84,9 +88,93 @@ t_admins_add_delete(_) ->
     ?assertNotEqual(true, request_dashboard(get, api_path("brokers"),
         auth_header_("username", "pwd"))).
 
+t_admins_persist_default_password(_) ->
+    emqx_dashboard_admin:change_password(<<"admin">>, <<"new_password">>),
+    ct:sleep(100),
+    [#mqtt_admin{password=Password, tags= <<"administrator">>}] = emqx_dashboard_admin:lookup_user(<<"admin">>),
+
+    %% To ensure that state persists even if the process dies
+    application:stop(emqx_dashboard),
+    application:start(emqx_dashboard),
+
+    ct:sleep(100),
+
+    %% It get's restarted by the app automatically
+    [#mqtt_admin{password=PasswordAfterRestart}] = emqx_dashboard_admin:lookup_user(<<"admin">>),
+    ?assertEqual(Password, PasswordAfterRestart),
+    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).
+
+debug(Label, Slave) ->
+    ct:print(
+      "[~p]~nusers local ~p~nusers remote: ~p~nenv local: ~p~nenv remote: ~p",
+      [
+       Label,
+       ets:tab2list(mqtt_admin),
+       rpc:call(Slave, ets, tab2list, [mqtt_admin]),
+       application:get_all_env(emqx_dashboard),
+       rpc:call(Slave, application, get_all_env, [emqx_dashboard])
+      ]).
+
+
+t_default_password_persists_after_leaving_cluster(_) ->
+    [#mqtt_admin{password=InitialPassword}] = emqx_dashboard_admin:lookup_user(<<"admin">>),
+
+    ct:print("Cluster status: ~p", [ekka_cluster:info()]),
+    ct:print("Table nodes: ~p", [mnesia:table_info(mqtt_admin, active_replicas)]),
+
+    Slave = start_slave('test1', [emqx_modules, emqx_management, emqx_dashboard]),
+
+    %% To make sure that subscription is not lost during reconnection
+    rpc:call(Slave, ekka, leave, []),
+    ct:sleep(100), %% To ensure that leave gets processed
+    rpc:call(Slave, ekka, join, [node()]),
+    ct:sleep(100), %% To ensure that join gets processed
+
+    ct:print("Cluster status: ~p", [ekka_cluster:info()]),
+    ct:print("Table nodes: ~p", [mnesia:table_info(mqtt_admin, active_replicas)]),
+
+    ct:print("Apps: ~p", [
+                          rpc:call(Slave, application, which_applications, [])
+                         ]),
+
+    debug(0, Slave),
+
+    emqx_dashboard_admin:change_password(<<"admin">>, <<"new_password">>),
+    ct:sleep(100), %% To ensure that event gets processed
+
+    debug(1, Slave),
+
+    [#mqtt_admin{password=Password}] = rpc:call(Slave, emqx_dashboard_admin, lookup_user, [<<"admin">>]),
+    ?assertNotEqual(InitialPassword, Password),
+
+    rpc:call(Slave, ekka, leave, []),
+
+    debug(2, Slave),
+
+    rpc:call(Slave, application, stop, [emqx_dashboard]),
+
+    debug(3, Slave),
+
+    rpc:call(Slave, application, start, [emqx_dashboard]),
+
+    debug(4, Slave),
+
+    ?assertEqual(
+       ok,
+       rpc:call(Slave, emqx_dashboard_admin, check, [<<"admin">>, <<"new_password">>])),
+
+    ?assertMatch(
+       {error, _},
+       rpc:call(Slave, emqx_dashboard_admin, check, [<<"admin">>, <<"password">>])),
+
+    {ok, _} = stop_slave(Slave, [emqx_dashboard, emqx_management, emqx_modules]),
+
+    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).
+
 t_rest_api(_Config) ->
     {ok, Res0} = http_get("users"),
     Users = get_http_data(Res0),
+    ct:pal("~p", [emqx_dashboard_admin:all_users()]),
     ?assert(lists:member(#{<<"username">> => <<"admin">>, <<"tags">> => <<"administrator">>},
         Users)),
 
@@ -170,3 +258,54 @@ api_path(Path) ->
 
 json(Data) ->
     {ok, Jsx} = emqx_json:safe_decode(Data, [return_maps]), Jsx.
+
+start_slave(Name, Apps) ->
+    {ok, Node} = ct_slave:start(list_to_atom(atom_to_list(Name) ++ "@" ++ host()),
+                                [{kill_if_fail, true},
+                                 {monitor_master, true},
+                                 {init_timeout, 10000},
+                                 {startup_timeout, 10000},
+                                 {erl_flags, ebin_path()}]),
+
+    pong = net_adm:ping(Node),
+    setup_node(Node, Apps),
+    Node.
+
+stop_slave(Node, Apps) ->
+    [ok = Res || Res <- rpc:call(Node, emqx_ct_helpers, stop_apps, [Apps])],
+    rpc:call(Node, ekka, leave, []),
+    ct_slave:stop(Node).
+
+host() ->
+    [_, Host] = string:tokens(atom_to_list(node()), "@"), Host.
+
+ebin_path() ->
+    string:join(["-pa" | lists:filter(fun is_lib/1, code:get_path())], " ").
+
+is_lib(Path) ->
+    string:prefix(Path, code:lib_dir()) =:= nomatch.
+
+setup_node(Node, Apps) ->
+    EnvHandler =
+        fun(emqx) ->
+                application:set_env(emqx, listeners, []),
+                application:set_env(gen_rpc, port_discovery, manual),
+                ok;
+           (emqx_management) ->
+                application:set_env(emqx_management, listeners, []),
+                ok;
+           (emqx_dashboard) ->
+                application:set_env(emqx_dashboard, listeners, []),
+                ok;
+           (_) ->
+                ok
+        end,
+
+    [ok = rpc:call(Node, application, load, [App]) || App <- [gen_rpc, emqx | Apps]],
+    ok = rpc:call(Node, emqx_ct_helpers, start_apps, [Apps, EnvHandler]),
+
+    rpc:call(Node, ekka, join, [node()]),
+    rpc:call(Node, application, stop, [emqx_dashboard]),
+    rpc:call(Node, application, start, [emqx_dashboard]),
+
+    ok.
diff --git a/src/emqx.appup.src b/src/emqx.appup.src
index 8825da442..17a0e92e9 100644
--- a/src/emqx.appup.src
+++ b/src/emqx.appup.src
@@ -3,13 +3,12 @@
 {VSN,
   [{"4.3.14",
     [{load_module,emqx_frame,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_hooks,brutal_purge,soft_purge,[]},
+     {load_module,emqx,brutal_purge,soft_purge,[]}]},
    {"4.3.13",
-    [{load_module,emqx_plugins,brutal_purge,soft_purge,[]},
-     {load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
+     {load_module,emqx,brutal_purge,soft_purge,[]},
+     {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_frame,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys_mon,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
@@ -21,12 +20,9 @@
      {load_module,emqx_ctl,brutal_purge,soft_purge,[]},
      {load_module,emqx_cm,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
-     {load_module,emqx_connection,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_connection,brutal_purge,soft_purge,[]}]},
    {"4.3.12",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_frame,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -48,12 +44,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.11",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -77,12 +70,9 @@
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_http_lib,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.10",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -106,12 +96,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_connection,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.9",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -139,12 +126,9 @@
      {load_module,emqx_os_mon,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.8",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -172,12 +156,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.7",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -206,12 +187,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.6",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -240,12 +218,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.5",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -275,11 +250,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.4",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -310,11 +283,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.3",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -346,11 +317,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.2",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -382,11 +351,9 @@
      {load_module,emqx_os_mon,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.1",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys,brutal_purge,soft_purge,[]},
@@ -421,11 +388,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.0",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys,brutal_purge,soft_purge,[]},
@@ -463,18 +428,16 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
   [{"4.3.14",
     [{load_module,emqx_frame,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_hooks,brutal_purge,soft_purge,[]},
+     {load_module,emqx,brutal_purge,soft_purge,[]}]},
    {"4.3.13",
-    [{load_module,emqx_plugins,brutal_purge,soft_purge,[]},
-     {load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
+     {load_module,emqx,brutal_purge,soft_purge,[]},
+     {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_frame,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys_mon,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
@@ -486,12 +449,9 @@
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_ctl,brutal_purge,soft_purge,[]},
      {load_module,emqx_cm,brutal_purge,soft_purge,[]},
-     {load_module,emqx_connection,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_connection,brutal_purge,soft_purge,[]}]},
    {"4.3.12",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_frame,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys_mon,brutal_purge,soft_purge,[]},
@@ -512,12 +472,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.11",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -540,12 +497,9 @@
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_http_lib,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.10",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -568,12 +522,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_connection,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.9",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -600,12 +551,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.8",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_misc,brutal_purge,soft_purge,[]},
@@ -632,12 +580,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.7",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -665,12 +610,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.6",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -698,12 +640,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.5",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
-     {load_module,emqx_shared_sub,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -732,11 +671,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.4",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -766,11 +703,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.3",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -801,11 +736,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.2",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
@@ -836,11 +769,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.1",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys,brutal_purge,soft_purge,[]},
@@ -874,11 +805,9 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {"4.3.0",
-    [{load_module,emqx_flapping,brutal_purge,soft_purge,[]},
-     {load_module,emqx_listeners,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_hooks,brutal_purge,soft_purge,[]},
      {load_module,emqx_pmon,brutal_purge,soft_purge,[]},
      {load_module,emqx_banned,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys,brutal_purge,soft_purge,[]},
@@ -914,6 +843,5 @@
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]},
      {load_module,emqx_message,brutal_purge,soft_purge,[]},
-     {load_module,emqx_limiter,brutal_purge,soft_purge,[]},
-     {load_module,emqx_hooks,brutal_purge,soft_purge,[]}]},
+     {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}]}.
diff --git a/src/emqx.erl b/src/emqx.erl
index 5c90cf953..7fb3c734f 100644
--- a/src/emqx.erl
+++ b/src/emqx.erl
@@ -234,7 +234,19 @@ shutdown(Reason) ->
                  ).
 
 reboot() ->
-    lists:foreach(fun application:start/1 , default_started_applications()).
+    case is_application_running(emqx_dashboard) of
+        true ->
+            application:stop(emqx_dashboard), %% dashboard must be started after mnesia
+            lists:foreach(fun application:start/1 , default_started_applications()),
+            application:start(emqx_dashboard);
+
+        false ->
+            lists:foreach(fun application:start/1 , default_started_applications())
+    end.
+
+is_application_running(App) ->
+    StartedApps = proplists:get_value(started, application:info()),
+    proplists:is_defined(App, StartedApps).
 
 -ifdef(EMQX_ENTERPRISE).
 default_started_applications() ->

From 0d4822ba781655abb1d71c68db64794dec8de855 Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Tue, 5 Apr 2022 10:52:11 +0200
Subject: [PATCH 2/7] refactor(emqx_dashboard_admin): simplify default pwd
 read/write

---
 .../src/emqx_dashboard_admin.erl              | 74 ++++++++++++-------
 1 file changed, 48 insertions(+), 26 deletions(-)

diff --git a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
index 505c468cd..8c4611a8b 100644
--- a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
+++ b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
@@ -156,13 +156,15 @@ update_pwd(Username, Fun) ->
 
 -spec(lookup_user(binary()) -> [mqtt_admin()]).
 lookup_user(Username) when is_binary(Username) ->
-    case binenv(default_user_username) of
-        Username ->
-            Password = hashed_default_passwd(),
-            [#mqtt_admin{username=Username, password=Password, tags= <<"administrator">>}];
+    IsDefaultUser = binenv(default_user_username) =:= Username,
+    case mnesia:dirty_read(mqtt_admin, Username) of
+        [] when IsDefaultUser ->
+            _ = ensure_default_user_in_db(Username),
+            ok;
         _ ->
-            mnesia:dirty_read(mqtt_admin, Username)
-    end.
+            ok
+    end,
+    mnesia:dirty_read(mqtt_admin, Username).
 
 -spec(all_users() -> [#mqtt_admin{}]).
 all_users() -> ets:tab2list(mqtt_admin).
@@ -194,7 +196,8 @@ check(Username, Password) ->
 init([]) ->
     %% Add default admin user
     {ok, _} = mnesia:subscribe({table, mqtt_admin, simple}),
-    add_default_user_hashed(binenv(default_user_username), hashed_default_passwd()),
+    PasswordHash = ensure_default_user_in_db(binenv(default_user_username)),
+    ok = ensure_default_user_passwd_hashed_in_app_env(PasswordHash),
     {ok, state}.
 
 handle_call(_Req, _From, State) ->
@@ -204,11 +207,11 @@ handle_cast(_Msg, State) ->
     {noreply, State}.
 
 handle_info({mnesia_table_event, {write, Admin, _}}, State) ->
-    #mqtt_admin{username=Username, password=HashedPassword} = Admin,
+    %% the password is chagned from another node, sync it to app env
+    #mqtt_admin{username = Username, password = HashedPassword} = Admin,
     case binenv(default_user_username) of
         Username ->
-            application:set_env(emqx_dashboard, default_user_passwd_hashed, HashedPassword);
-
+            ok = ensure_default_user_passwd_hashed_in_app_env(HashedPassword);
         _ ->
             ignore
     end,
@@ -242,24 +245,43 @@ salt() ->
 binenv(Key) ->
     iolist_to_binary(application:get_env(emqx_dashboard, Key, <<>>)).
 
-add_default_user_hashed(Username, HashedPassword) ->
-    case mnesia:dirty_read(mqtt_admin, Username) of
-        [] ->
-            Admin = #mqtt_admin{username=Username, password=HashedPassword, tags= <<"administrator">>},
-            return(mnesia:transaction(fun add_user_/1, [Admin]));
-        _  -> ok
-    end.
+ensure_default_user_in_db(Username) ->
+    F =
+        fun() ->
+                case mnesia:wread(mqtt_admin, Username) of
+                    [] ->
+                        PasswordHash = initial_default_user_passwd_hashed(),
+                        Admin = #mqtt_admin{username = Username,
+                                            password = PasswordHash,
+                                            tags = <<"administrator">>},
+                        ok = mnesia:write(Admin),
+                        PasswordHash;
+                    [#mqtt_admin{password = PasswordHash}] ->
+                        PasswordHash
+                end
+        end,
+    {atomic, PwdHash} = mnesia:transaction(F),
+    PwdHash.
 
-hashed_default_passwd() ->
-    case binenv(default_user_passwd_hashed) of
-        Empty0 when ?EMPTY_KEY(Empty0) ->
+initial_default_user_passwd_hashed() ->
+    case get_default_user_passwd_hashed_in_app_env() of
+        Empty when ?EMPTY_KEY(Empty) ->
+            %% in case it's not set yet
             case binenv(default_user_passwd) of
                 Empty when ?EMPTY_KEY(Empty) ->
-                    undefined;
-                Password ->
-                    Hashed = hash(Password),
-                    application:set_env(emqx_dashboard, default_user_passwd_hashed, Hashed),
-                    Hashed
+                    error({missing_configuration, default_user_passwd});
+                Pwd ->
+                    hash(Pwd)
             end;
-        HashedPassword -> HashedPassword
+        PwdHash ->
+            PwdHash
     end.
+
+%% use this app env for a copy of the value in mnesia database
+%% so that after the node leaves a cluster, db gets purged,
+%% we can still find the changed password back from this app env
+ensure_default_user_passwd_hashed_in_app_env(Hashed) ->
+    ok = application:set_env(emqx_dashboard, default_user_passwd_hashed, Hashed).
+
+get_default_user_passwd_hashed_in_app_env() ->
+    application:get_env(emqx_dashboard, default_user_passwd_hashed, <<>>).

From 6cc55f5c349a2e25cf2dda860422741ff85c365f Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Tue, 5 Apr 2022 12:22:04 +0200
Subject: [PATCH 3/7] chore: add back the default password warning

---
 .../src/emqx_dashboard_admin.erl              | 25 ++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
index 8c4611a8b..185737148 100644
--- a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
+++ b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
@@ -21,6 +21,7 @@
 -behaviour(gen_server).
 
 -include("emqx_dashboard.hrl").
+-include_lib("emqx/include/logger.hrl").
 
 -boot_mnesia({mnesia, [boot]}).
 -copy_mnesia({mnesia, [copy]}).
@@ -180,8 +181,8 @@ check(_, undefined) ->
     {error, <<"Password undefined">>};
 check(Username, Password) ->
     case lookup_user(Username) of
-        [#mqtt_admin{password = <<Salt:4/binary, Hash/binary>>}] ->
-            case Hash =:= md5_hash(Salt, Password) of
+        [#mqtt_admin{password = PwdHash}] ->
+            case is_valid_pwd(PwdHash, Password) of
                 true  -> ok;
                 false -> {error, <<"Username/Password error">>}
             end;
@@ -189,6 +190,9 @@ check(Username, Password) ->
             {error, <<"Username/Password error">>}
     end.
 
+is_valid_pwd(<<Salt:4/binary, Hash/binary>>, Password) ->
+    Hash =:= md5_hash(Salt, Password).
+
 %%--------------------------------------------------------------------
 %% gen_server callbacks
 %%--------------------------------------------------------------------
@@ -198,6 +202,7 @@ init([]) ->
     {ok, _} = mnesia:subscribe({table, mqtt_admin, simple}),
     PasswordHash = ensure_default_user_in_db(binenv(default_user_username)),
     ok = ensure_default_user_passwd_hashed_in_app_env(PasswordHash),
+    ok = maybe_warn_default_pwd(),
     {ok, state}.
 
 handle_call(_Req, _From, State) ->
@@ -248,7 +253,7 @@ binenv(Key) ->
 ensure_default_user_in_db(Username) ->
     F =
         fun() ->
-                case mnesia:wread(mqtt_admin, Username) of
+                case mnesia:wread({mqtt_admin, Username}) of
                     [] ->
                         PasswordHash = initial_default_user_passwd_hashed(),
                         Admin = #mqtt_admin{username = Username,
@@ -285,3 +290,17 @@ ensure_default_user_passwd_hashed_in_app_env(Hashed) ->
 
 get_default_user_passwd_hashed_in_app_env() ->
     application:get_env(emqx_dashboard, default_user_passwd_hashed, <<>>).
+
+maybe_warn_default_pwd() ->
+    case is_valid_pwd(initial_default_user_passwd_hashed(), <<"public">>) of
+        true ->
+            ?LOG(warning,
+                 "[Dashboard] Using default password for dashboard 'admin' user. "
+                 "Please use the './bin/emqx_ctl admins' CLI to change it. "
+                 "NOTE: the default password in config file is only "
+                 "used to initialise the database record, changing the config "
+                 "file after database is initialised has no effect."
+                );
+        false ->
+            ok
+    end.

From 155befe418e5cb604d6cf054785d4db5dc7a4fab Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Tue, 5 Apr 2022 13:23:44 +0200
Subject: [PATCH 4/7] chore: no duplicated reads and some comment/message
 rewording

Co-authored-by: Dmitrii <99872536+ieQu1@users.noreply.github.com>
---
 lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl  | 12 ++++++------
 lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
index 185737148..24fd58e1e 100644
--- a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
+++ b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
@@ -161,11 +161,11 @@ lookup_user(Username) when is_binary(Username) ->
     case mnesia:dirty_read(mqtt_admin, Username) of
         [] when IsDefaultUser ->
             _ = ensure_default_user_in_db(Username),
-            ok;
-        _ ->
-            ok
-    end,
-    mnesia:dirty_read(mqtt_admin, Username).
+            %% try to read again
+            mnesia:dirty_read(mqtt_admin, Username);
+        Res ->
+            Res
+    end.
 
 -spec(all_users() -> [#mqtt_admin{}]).
 all_users() -> ets:tab2list(mqtt_admin).
@@ -296,7 +296,7 @@ maybe_warn_default_pwd() ->
         true ->
             ?LOG(warning,
                  "[Dashboard] Using default password for dashboard 'admin' user. "
-                 "Please use the './bin/emqx_ctl admins' CLI to change it. "
+                 "Please use './bin/emqx_ctl admins' command to change it. "
                  "NOTE: the default password in config file is only "
                  "used to initialise the database record, changing the config "
                  "file after database is initialised has no effect."
diff --git a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
index 28d80ae7d..f9d6e5b78 100644
--- a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
+++ b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
@@ -99,7 +99,7 @@ t_admins_persist_default_password(_) ->
 
     ct:sleep(100),
 
-    %% It get's restarted by the app automatically
+    %% It gets restarted by the app automatically
     [#mqtt_admin{password=PasswordAfterRestart}] = emqx_dashboard_admin:lookup_user(<<"admin">>),
     ?assertEqual(Password, PasswordAfterRestart),
     emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).

From d219e475fb7a5942b358ee5db7de389d5b5af781 Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Tue, 5 Apr 2022 13:56:43 +0200
Subject: [PATCH 5/7] fix(emqx_dashboard_admin): put changed default user pwd
 in pt

plugin app envs are all unloaded when the app reboots
---
 .../src/emqx_dashboard_admin.erl              | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
index 24fd58e1e..8b35d167d 100644
--- a/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
+++ b/lib-ce/emqx_dashboard/src/emqx_dashboard_admin.erl
@@ -201,7 +201,7 @@ init([]) ->
     %% Add default admin user
     {ok, _} = mnesia:subscribe({table, mqtt_admin, simple}),
     PasswordHash = ensure_default_user_in_db(binenv(default_user_username)),
-    ok = ensure_default_user_passwd_hashed_in_app_env(PasswordHash),
+    ok = ensure_default_user_passwd_hashed_in_pt(PasswordHash),
     ok = maybe_warn_default_pwd(),
     {ok, state}.
 
@@ -212,11 +212,11 @@ handle_cast(_Msg, State) ->
     {noreply, State}.
 
 handle_info({mnesia_table_event, {write, Admin, _}}, State) ->
-    %% the password is chagned from another node, sync it to app env
+    %% the password is chagned from another node, sync it to persistent_term
     #mqtt_admin{username = Username, password = HashedPassword} = Admin,
     case binenv(default_user_username) of
         Username ->
-            ok = ensure_default_user_passwd_hashed_in_app_env(HashedPassword);
+            ok = ensure_default_user_passwd_hashed_in_pt(HashedPassword);
         _ ->
             ignore
     end,
@@ -269,7 +269,7 @@ ensure_default_user_in_db(Username) ->
     PwdHash.
 
 initial_default_user_passwd_hashed() ->
-    case get_default_user_passwd_hashed_in_app_env() of
+    case get_default_user_passwd_hashed_from_pt() of
         Empty when ?EMPTY_KEY(Empty) ->
             %% in case it's not set yet
             case binenv(default_user_passwd) of
@@ -282,14 +282,14 @@ initial_default_user_passwd_hashed() ->
             PwdHash
     end.
 
-%% use this app env for a copy of the value in mnesia database
+%% use this persistent_term for a copy of the value in mnesia database
 %% so that after the node leaves a cluster, db gets purged,
-%% we can still find the changed password back from this app env
-ensure_default_user_passwd_hashed_in_app_env(Hashed) ->
-    ok = application:set_env(emqx_dashboard, default_user_passwd_hashed, Hashed).
+%% we can still find the changed password back from PT
+ensure_default_user_passwd_hashed_in_pt(Hashed) ->
+    ok = persistent_term:put({?MODULE, default_user_passwd_hashed}, Hashed).
 
-get_default_user_passwd_hashed_in_app_env() ->
-    application:get_env(emqx_dashboard, default_user_passwd_hashed, <<>>).
+get_default_user_passwd_hashed_from_pt() ->
+    persistent_term:get({?MODULE, default_user_passwd_hashed}, <<>>).
 
 maybe_warn_default_pwd() ->
     case is_valid_pwd(initial_default_user_passwd_hashed(), <<"public">>) of

From 164209b576fbb27f997f1e3e69a983a2e182a23a Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Tue, 5 Apr 2022 22:29:43 +0200
Subject: [PATCH 6/7] test: use end_per_testcase to restore default admin
 password

---
 lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
index f9d6e5b78..8bba12242 100644
--- a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
+++ b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
@@ -65,6 +65,13 @@ end_per_suite(_Config) ->
     emqx_ct_helpers:stop_apps([emqx_dashboard, emqx_management, emqx_modules]),
     ekka_mnesia:ensure_stopped().
 
+init_per_testcase(_, Config) ->
+    Config.
+
+end_per_testcase(_, _) ->
+    %% revert to default password
+    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).
+
 t_overview(_) ->
     [?assert(request_dashboard(get, api_path(erlang:atom_to_list(Overview)), auth_header_()))|| Overview <- ?OVERVIEWS].
 
@@ -101,8 +108,7 @@ t_admins_persist_default_password(_) ->
 
     %% It gets restarted by the app automatically
     [#mqtt_admin{password=PasswordAfterRestart}] = emqx_dashboard_admin:lookup_user(<<"admin">>),
-    ?assertEqual(Password, PasswordAfterRestart),
-    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).
+    ?assertEqual(Password, PasswordAfterRestart).
 
 debug(Label, Slave) ->
     ct:print(
@@ -168,8 +174,7 @@ t_default_password_persists_after_leaving_cluster(_) ->
        rpc:call(Slave, emqx_dashboard_admin, check, [<<"admin">>, <<"password">>])),
 
     {ok, _} = stop_slave(Slave, [emqx_dashboard, emqx_management, emqx_modules]),
-
-    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).
+    ok.
 
 t_rest_api(_Config) ->
     {ok, Res0} = http_get("users"),

From c422edd977571f9ba82dfc93368c873ac92ef3d9 Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Tue, 5 Apr 2022 23:41:35 +0200
Subject: [PATCH 7/7] test(emqx_dashboard_SUITE): add init/end_per_testcase

---
 .../test/emqx_dashboard_SUITE.erl             | 35 ++++++++++++++-----
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
index 8bba12242..556fb8371 100644
--- a/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
+++ b/lib-ce/emqx_dashboard/test/emqx_dashboard_SUITE.erl
@@ -65,16 +65,21 @@ end_per_suite(_Config) ->
     emqx_ct_helpers:stop_apps([emqx_dashboard, emqx_management, emqx_modules]),
     ekka_mnesia:ensure_stopped().
 
-init_per_testcase(_, Config) ->
-    Config.
+init_per_testcase(Case, Config) ->
+    ?MODULE:Case({init, Config}).
 
-end_per_testcase(_, _) ->
+end_per_testcase(Case, Config) ->
     %% revert to default password
-    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>).
+    emqx_dashboard_admin:change_password(<<"admin">>, <<"public">>),
+    ?MODULE:Case({'end', Config}).
 
+t_overview({init, Config}) -> Config;
+t_overview({'end', _Config}) -> ok;
 t_overview(_) ->
     [?assert(request_dashboard(get, api_path(erlang:atom_to_list(Overview)), auth_header_()))|| Overview <- ?OVERVIEWS].
 
+t_admins_add_delete({init, Config}) -> Config;
+t_admins_add_delete({'end', _Config}) -> ok;
 t_admins_add_delete(_) ->
     ok = emqx_dashboard_admin:add_user(<<"username">>, <<"password">>, <<"tag">>),
     ok = emqx_dashboard_admin:add_user(<<"username1">>, <<"password1">>, <<"tag1">>),
@@ -95,6 +100,8 @@ t_admins_add_delete(_) ->
     ?assertNotEqual(true, request_dashboard(get, api_path("brokers"),
         auth_header_("username", "pwd"))).
 
+t_admins_persist_default_password({init, Config}) -> Config;
+t_admins_persist_default_password({'end', _Config}) -> ok;
 t_admins_persist_default_password(_) ->
     emqx_dashboard_admin:change_password(<<"admin">>, <<"new_password">>),
     ct:sleep(100),
@@ -122,13 +129,20 @@ debug(Label, Slave) ->
       ]).
 
 
-t_default_password_persists_after_leaving_cluster(_) ->
+t_default_password_persists_after_leaving_cluster({init, Config}) ->
+    Slave = start_slave('test1', [emqx_modules, emqx_management, emqx_dashboard]),
+    [{slave, Slave} | Config];
+t_default_password_persists_after_leaving_cluster({'end', Config}) ->
+    Slave = proplists:get_value(slave, Config),
+    {ok, _} = stop_slave(Slave, [emqx_dashboard, emqx_management, emqx_modules]),
+    ok;
+t_default_password_persists_after_leaving_cluster(Config) ->
+    Slave = proplists:get_value(slave, Config),
     [#mqtt_admin{password=InitialPassword}] = emqx_dashboard_admin:lookup_user(<<"admin">>),
 
     ct:print("Cluster status: ~p", [ekka_cluster:info()]),
     ct:print("Table nodes: ~p", [mnesia:table_info(mqtt_admin, active_replicas)]),
 
-    Slave = start_slave('test1', [emqx_modules, emqx_management, emqx_dashboard]),
 
     %% To make sure that subscription is not lost during reconnection
     rpc:call(Slave, ekka, leave, []),
@@ -172,10 +186,10 @@ t_default_password_persists_after_leaving_cluster(_) ->
     ?assertMatch(
        {error, _},
        rpc:call(Slave, emqx_dashboard_admin, check, [<<"admin">>, <<"password">>])),
-
-    {ok, _} = stop_slave(Slave, [emqx_dashboard, emqx_management, emqx_modules]),
     ok.
 
+t_rest_api({init, Config}) -> Config;
+t_rest_api({'end', _Config}) -> ok;
 t_rest_api(_Config) ->
     {ok, Res0} = http_get("users"),
     Users = get_http_data(Res0),
@@ -196,11 +210,15 @@ t_rest_api(_Config) ->
              ]],
     ok.
 
+t_auth_exhaustive_attack({init, Config}) -> Config;
+t_auth_exhaustive_attack({'end', _Config}) -> ok;
 t_auth_exhaustive_attack(_Config) ->
     {ok, Res0} = http_post("auth", #{<<"username">> => <<"invalid_login">>, <<"password">> => <<"newpwd">>}),
     {ok, Res1} = http_post("auth", #{<<"username">> => <<"admin">>, <<"password">> => <<"invalid_password">>}),
     ?assertEqual(Res0, Res1).
 
+t_cli({init, Config}) -> Config;
+t_cli({'end', _Config}) -> ok;
 t_cli(_Config) ->
     [mnesia:dirty_delete({mqtt_admin, Admin}) ||  Admin <- mnesia:dirty_all_keys(mqtt_admin)],
     emqx_dashboard_cli:admins(["add", "username", "password"]),
@@ -312,5 +330,4 @@ setup_node(Node, Apps) ->
     rpc:call(Node, ekka, join, [node()]),
     rpc:call(Node, application, stop, [emqx_dashboard]),
     rpc:call(Node, application, start, [emqx_dashboard]),
-
     ok.