fix: don't router request until dispatch is ready

apps/emqx_dashboard/src/emqx_dashboard_listener.erl

@@ -25,7 +25,7 @@
 
 -behaviour(gen_server).
 
--export([start_link/0, is_ready/0]).
+-export([start_link/0, is_ready/1]).
 
 -export([
     init/1,
@@ -37,8 +37,8 @@
     code_change/3
 ]).
 
-is_ready() ->
-    ready =:= gen_server:call(?MODULE, get_state, 10000).
+is_ready(Timeout) ->
+    ready =:= gen_server:call(?MODULE, get_state, Timeout).
 
 start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).

apps/emqx_dashboard/src/emqx_dashboard_middleware.erl

@@ -21,33 +21,27 @@
 -export([execute/2]).
 
 execute(Req, Env) ->
-    waiting_dispatch_ready(),
+    case check_dispatch_ready(Env) of
+        true -> add_cors_flag(Req, Env);
+        false -> {stop, cowboy_req:reply(503, Req)}
+    end.
+
+add_cors_flag(Req, Env) ->
     CORS = emqx_conf:get([dashboard, cors], false),
-    case CORS andalso cowboy_req:header(<<"origin">>, Req, undefined) of
+    Origin = cowboy_req:header(<<"origin">>, Req, undefined),
+    case CORS andalso Origin =/= undefined of
         false ->
             {ok, Req, Env};
-        undefined ->
-            {ok, Req, Env};
-        _ ->
+        true ->
             Req2 = cowboy_req:set_resp_header(<<"Access-Control-Allow-Origin">>, <<"*">>, Req),
             {ok, Req2, Env}
     end.
 
-waiting_dispatch_ready() ->
-    waiting_dispatch_ready(5).
-
-waiting_dispatch_ready(0) ->
-    ok;
-waiting_dispatch_ready(Count) ->
-    case emqx_sys:uptime() < timer:minutes(1) of
-        true ->
-            case emqx_dashboard_listener:is_ready() of
-                true ->
-                    ok;
-                false ->
-                    timer:sleep(100),
-                    waiting_dispatch_ready(Count - 1)
-            end;
+check_dispatch_ready(Env) ->
+    case maps:is_key(options, Env) of
         false ->
-            ok
+            true;
+        true ->
+            %% dashboard should always ready, if not, is_ready/1 will block until ready.
+            emqx_dashboard_listener:is_ready(timer:seconds(15))
     end.