From 1021088f5f96296ef84636355e51340a9dec1232 Mon Sep 17 00:00:00 2001
From: zhongwencool <zhongwencool@gmail.com>
Date: Thu, 12 Oct 2023 15:23:23 +0800
Subject: [PATCH] fix: 500 error response when downloading non-existent trace
 files

---
 apps/emqx_management/src/emqx_mgmt_api_trace.erl      |  2 ++
 .../test/emqx_mgmt_api_trace_SUITE.erl                | 11 ++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/apps/emqx_management/src/emqx_mgmt_api_trace.erl b/apps/emqx_management/src/emqx_mgmt_api_trace.erl
index bcc21a97b..4aff66efc 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_trace.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_trace.erl
@@ -552,6 +552,8 @@ group_trace_files(TraceLog, TraceFiles) ->
                 empty;
             ({ok, _Node, _Bin}) ->
                 nonempty;
+            ({error, _Node, enoent}) ->
+                empty;
             ({error, Node, Reason}) ->
                 ?SLOG(error, #{
                     msg => "download_trace_log_error",
diff --git a/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl b/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl
index f4725b453..9b8222d20 100644
--- a/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl
+++ b/apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl
@@ -389,7 +389,16 @@ t_download_empty_trace(_Config) ->
     ),
     {error, {{_, 404, _}, _Headers, Body}} =
         request_api(get, api_path(<<"trace/", Name/binary, "/download">>), [], #{return_all => true}),
-    ?assertMatch(#{<<"message">> := <<"Trace is empty">>}, emqx_utils_json:decode(Body)).
+    ?assertMatch(#{<<"message">> := <<"Trace is empty">>}, emqx_utils_json:decode(Body)),
+    File = emqx_trace:log_file(Name, Now),
+    ct:pal("FileName: ~p", [File]),
+    ?assertEqual({ok, <<>>}, file:read_file(File)),
+    ?assertEqual(ok, file:delete(File)),
+    %% return 404 if trace file is not found
+    {error, {{_, 404, _}, _Headers, Body}} =
+        request_api(get, api_path(<<"trace/", Name/binary, "/download">>), [], #{return_all => true}),
+    ?assertMatch(#{<<"message">> := <<"Trace is empty">>}, emqx_utils_json:decode(Body)),
+    ok.
 
 to_rfc3339(Second) ->
     list_to_binary(calendar:system_time_to_rfc3339(Second)).