From 73643e932fdf1e2f5db23d73feb7a11460b1da8c Mon Sep 17 00:00:00 2001
From: Shawn <506895667@qq.com>
Date: Tue, 10 Jan 2023 16:43:24 +0800
Subject: [PATCH] fix: bulk subscribe topics failed in the client.connected
 hook

---
 apps/emqx_management/src/emqx_mgmt_api_clients.erl | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/apps/emqx_management/src/emqx_mgmt_api_clients.erl b/apps/emqx_management/src/emqx_mgmt_api_clients.erl
index f078f4d2a..7c45206fd 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_clients.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_clients.erl
@@ -718,15 +718,18 @@ subscribe(#{clientid := ClientID, topic := Topic} = Sub) ->
     end.
 
 subscribe_batch(#{clientid := ClientID, topics := Topics}) ->
-    case lookup(#{clientid => ClientID}) of
-        {200, _} ->
+    %% We use emqx_channel instead of emqx_channel_info (used by the emqx_mgmt:lookup_client/2),
+    %% as the emqx_channel_info table will only be populated after the hook `client.connected`
+    %% has returned. So if one want to subscribe topics in this hook, it will fail.
+    case ets:lookup(emqx_channel, ClientID) of
+        [] ->
+            {404, ?CLIENT_ID_NOT_FOUND};
+        _ ->
             ArgList = [
                 [ClientID, Topic, maps:with([qos, nl, rap, rh], Sub)]
              || #{topic := Topic} = Sub <- Topics
             ],
-            {200, emqx_mgmt_util:batch_operation(?MODULE, do_subscribe, ArgList)};
-        {404, ?CLIENT_ID_NOT_FOUND} ->
-            {404, ?CLIENT_ID_NOT_FOUND}
+            {200, emqx_mgmt_util:batch_operation(?MODULE, do_subscribe, ArgList)}
     end.
 
 unsubscribe(#{clientid := ClientID, topic := Topic}) ->