fix emqttd_ctl crashed when emq_auth_usename doesn't exist

src/emqttd_cli.erl

@@ -30,7 +30,7 @@
 
 -export([load/0]).
 
--export([status/1, broker/1, cluster/1, users/1, clients/1, sessions/1,
+-export([status/1, broker/1, cluster/1, clients/1, sessions/1,
          routes/1, topics/1, subscriptions/1, plugins/1, bridges/1,
          listeners/1, vm/1, mnesia/1, trace/1, acl/1]).
 
@@ -152,9 +152,7 @@ cluster(_) ->
             {"cluster status",            "Cluster status"}]).
 
 %%--------------------------------------------------------------------
-%% @doc Users usage
+%% @doc ACL reload
-
-users(Args) -> emq_auth_username:cli(Args).
 
 acl(["reload"]) -> emqttd_access_control:reload_acl();
 acl(_) -> ?USAGE([{"acl reload", "reload etc/acl.conf"}]).
@@ -607,4 +605,3 @@ format(_, Val) ->
     Val.
 
 bin(S) -> iolist_to_binary(S).
-

src/emqttd_plugins.erl

@@ -99,7 +99,7 @@ list() ->
     case emqttd:env(plugins_etc_dir) of
         {ok, PluginsEtc} ->
             CfgFiles = filelib:wildcard("*.{conf,config}", PluginsEtc),
-            Plugins = [plugin(CfgFile) || CfgFile <- CfgFiles],
+            Plugins = all_plugin_attrs(CfgFiles),
             StartedApps = names(started_app),
             lists:map(fun(Plugin = #mqtt_plugin{name = Name}) ->
                           case lists:member(Name, StartedApps) of
@@ -111,12 +111,24 @@ list() ->
             []
     end.
 
+all_plugin_attrs(CfgFiles) ->
+    lists:foldl(
+      fun(CfgFile, Acc) ->
+          case plugin(CfgFile) of
+              not_found -> Acc;
+              Attr -> Acc ++ [Attr]
+          end
+      end, [], CfgFiles).
+
 plugin(CfgFile) ->
     AppName = app_name(CfgFile),
-    {ok, Attrs} = application:get_all_key(AppName),
+    case application:get_all_key(AppName) of
+        {ok, Attrs} ->
             Ver = proplists:get_value(vsn, Attrs, "0"),
             Descr = proplists:get_value(description, Attrs, ""),
-    #mqtt_plugin{name = AppName, version = Ver, descr = Descr}.
+            #mqtt_plugin{name = AppName, version = Ver, descr = Descr};
+        _ -> not_found
+    end.
 
 %% @doc Load a Plugin
 -spec(load(atom()) -> ok | {error, term()}).
@@ -269,4 +281,3 @@ write_loaded(AppNames) ->
             lager:error("Open File ~p Error: ~p", [File, Error]),
             {error, Error}
     end.
-