fix: JSON trace formatter should handle report style log entries

Fixes:
https://emqx.atlassian.net/browse/EMQX-12344

apps/emqx/src/emqx_logger_jsonfmt.erl

@@ -34,6 +34,9 @@
 %% For CLI HTTP API outputs
 -export([best_effort_json/1, best_effort_json/2, best_effort_json_obj/1]).
 
+%% For emqx_trace_json_formatter
+-export([format_msg/3]).
+
 -ifdef(TEST).
 -include_lib("proper/include/proper.hrl").
 -include_lib("eunit/include/eunit.hrl").

apps/emqx/src/emqx_trace/emqx_trace_json_formatter.erl

@@ -23,6 +23,8 @@
 %% logger_formatter:config/0 is not exported.
 -type config() :: map().
 
+-define(DEFAULT_FORMATTER, fun logger:format_otp_report/1).
+
 %%%-----------------------------------------------------------------
 %%% Callback Function
 %%%-----------------------------------------------------------------
@@ -31,9 +33,10 @@
     LogEvent :: logger:log_event(),
     Config :: config().
 format(
-    LogMap0,
-    #{payload_encode := PEncode}
+    LogMap,
+    #{payload_encode := PEncode} = Config
 ) ->
+    LogMap0 = maybe_format_msg(LogMap, Config),
     LogMap1 = emqx_trace_formatter:evaluate_lazy_values(LogMap0),
     %% We just make some basic transformations on the input LogMap and then do
     %% an external call to create the JSON text
@@ -46,6 +49,40 @@ format(
 %%% Helper Functions
 %%%-----------------------------------------------------------------
 
+maybe_format_msg(#{msg := Msg, meta := Meta} = LogMap, Config) ->
+    try do_maybe_format_msg(Msg, Meta, Config) of
+        Map when is_map(Map) ->
+            LogMap#{meta => maps:merge(Meta, Map), msg => maps:get(msg, Map, "no_message")};
+        Bin when is_binary(Bin) ->
+            LogMap#{msg => Bin}
+    catch
+        C:R:S ->
+            Meta#{
+                amsg => Msg,
+                msg => "emqx_logger_jsonfmt_format_error",
+                fmt_raw_input => Msg,
+                fmt_error => C,
+                fmt_reason => R,
+                fmt_stacktrace => S,
+                more => {Msg, Meta, Config}
+            }
+    end.
+
+do_maybe_format_msg(String, _Meta, _Config) when is_list(String); is_binary(String) ->
+    unicode:characters_to_binary(String);
+do_maybe_format_msg(undefined, _Meta, _Config) ->
+    #{};
+do_maybe_format_msg({report, Report} = Msg, #{report_cb := Cb} = Meta, Config) ->
+    case is_map(Report) andalso Cb =:= ?DEFAULT_FORMATTER of
+        true ->
+            %% reporting a map without a customised format function
+            Report;
+        false ->
+            emqx_logger_jsonfmt:format_msg(Msg, Meta, Config)
+    end;
+do_maybe_format_msg(Msg, Meta, Config) ->
+    emqx_logger_jsonfmt:format_msg(Msg, Meta, Config).
+
 prepare_log_map(LogMap, PEncode) ->
     NewKeyValuePairs = [prepare_key_value(K, V, PEncode) || {K, V} <- maps:to_list(LogMap)],
     maps:from_list(NewKeyValuePairs).

apps/emqx_management/test/emqx_mgmt_api_trace_SUITE.erl

@@ -269,6 +269,8 @@ t_http_test_json_formatter(_Config) ->
         action_id =>
             <<"action:http:emqx_bridge_http_test_lib:connector:http:emqx_bridge_http_test_lib">>
     }),
+    %% We should handle report style logging
+    ?SLOG(error, #{msg => "recursive_republish_detected"}, #{topic => Topic}),
     ok = emqx_trace_handler_SUITE:filesync(Name, topic),
     {ok, _Detail2} = request_api(get, api_path("trace/" ++ binary_to_list(Name) ++ "/log_detail")),
     {ok, Bin} = request_api(get, api_path("trace/" ++ binary_to_list(Name) ++ "/download")),
@@ -410,6 +412,19 @@ t_http_test_json_formatter(_Config) ->
         },
         NextFun()
     ),
+    ?assertMatch(
+        #{
+            <<"level">> := <<"error">>,
+            <<"meta">> :=
+                #{
+                    <<"msg">> := <<"recursive_republish_detected">>,
+                    <<"topic">> := <<"/x/y/z">>
+                },
+            <<"msg">> := <<"recursive_republish_detected">>,
+            <<"time">> := _
+        },
+        NextFun()
+    ),
     {ok, Delete} = request_api(delete, api_path("trace/" ++ binary_to_list(Name))),
     ?assertEqual(<<>>, Delete),