fix: clear logger process metadata

Author: SergeTupchiy

apps/opentelemetry/test/opentelemetry_SUITE.erl

@@ -268,14 +268,14 @@ logger_metadata(_Config) ->
 
     ok.
 
-%% logger metadata will either be undefined, a map without the otel_span_ctx key or
-%% with the value of the key being undefined
+%% logger metadata will either be undefined, or a map without hex_span_ctx_keys:
+%%  [otel_trace_id, otel_span_id, ,otel_trace_flags]
 empty_metadata() ->
     case logger:get_process_metadata() of
         undefined ->
             true;
         M ->
-            maps:get(otel_span_ctx, M, #{}) =:= #{}
+            maps:with(otel_span:hex_span_ctx_keys(), M) =:= #{}
     end.
 
 propagator_configuration(_Config) ->

apps/opentelemetry_api/src/otel_ctx.erl

@@ -201,9 +201,5 @@ text_map_injector(Key, ToText) ->
 text_map_injector_fun(TextMap, Key, ToText) ->
     TextMap ++ ToText(?MODULE:get_value(Key, undefined)).
 
-%%
-
-update_logger_process_metadata(undefined) ->
-    ok;
 update_logger_process_metadata(Ctx) ->
     otel_tracer:update_logger_process_metadata(Ctx).

apps/opentelemetry_api/src/otel_span.erl

@@ -21,6 +21,7 @@
 -export([trace_id/1,
          span_id/1,
          hex_span_ctx/1,
+         hex_span_ctx_keys/0,
          hex_trace_id/1,
          hex_span_id/1,
          tracestate/1,
@@ -44,6 +45,9 @@
 -include_lib("opentelemetry_semantic_conventions/include/trace.hrl").
 
 -define(is_recording(SpanCtx), SpanCtx =/= undefined andalso SpanCtx#span_ctx.is_recording =:= true).
+-define(OTEL_TRACE_ID, otel_trace_id).
+-define(OTEL_SPAN_ID, otel_span_id).
+-define(OTEL_TRACE_FLAGS, otel_trace_flags).
 
 -type start_opts() :: #{attributes := opentelemetry:attributes_map(),
                         links := [opentelemetry:link()],
@@ -108,18 +112,22 @@ span_id(#span_ctx{span_id=SpanId}) ->
     SpanId.
 
 %% keys are prefixed with `otel_' because the main use of this function is logger metadata
--spec hex_span_ctx(opentelemetry:span_ctx() | undefined) -> #{otel_trace_id := unicode:charlist(),
-                                                              otel_span_id := unicode:charlist(),
-                                                              otel_trace_flags := unicode:charlist()} | #{}.
+-spec hex_span_ctx(opentelemetry:span_ctx() | undefined) -> #{?OTEL_TRACE_ID := unicode:charlist(),
+                                                              ?OTEL_SPAN_ID := unicode:charlist(),
+                                                              ?OTEL_TRACE_FLAGS := unicode:charlist()} | #{}.
 hex_span_ctx(#span_ctx{trace_id=TraceId,
                        span_id=SpanId,
                        trace_flags=TraceFlags}) ->
-    #{otel_trace_id => io_lib:format("~32.16.0b", [TraceId]),
-      otel_span_id => io_lib:format("~16.16.0b", [SpanId]),
-      otel_trace_flags => case TraceFlags band 1 of 1 -> "01"; _ -> "00" end};
+    #{?OTEL_TRACE_ID => io_lib:format("~32.16.0b", [TraceId]),
+      ?OTEL_SPAN_ID => io_lib:format("~16.16.0b", [SpanId]),
+      ?OTEL_TRACE_FLAGS => case TraceFlags band 1 of 1 -> "01"; _ -> "00" end};
 hex_span_ctx(_) ->
     #{}.
 
+-spec hex_span_ctx_keys() -> [atom()].
+hex_span_ctx_keys() ->
+    [?OTEL_TRACE_ID, ?OTEL_SPAN_ID, ?OTEL_TRACE_FLAGS].
+
 -spec hex_trace_id(opentelemetry:span_ctx()) -> opentelemetry:hex_trace_id().
 hex_trace_id(#span_ctx{trace_id=TraceId}) ->
     case otel_utils:format_binary_string("~32.16.0b", [TraceId]) of

apps/opentelemetry_api/src/otel_tracer.erl

@@ -127,8 +127,17 @@ current_span_ctx(Ctx) ->
 update_logger_process_metadata(Ctx) ->
     update_logger_process_metadata_from_span_ctx(current_span_ctx(Ctx)).
 
-%%
-
+%% If the (previous) context is undefined, logger process metadata must be cleared
+update_logger_process_metadata_from_span_ctx(undefined) ->
+    clear_logger_proces_metadata();
 update_logger_process_metadata_from_span_ctx(SpanCtx) ->
     Metadata = otel_span:hex_span_ctx(SpanCtx),
     logger:update_process_metadata(Metadata).
+
+clear_logger_proces_metadata() ->
+    case logger:get_process_metadata() of
+        M when is_map(M) ->
+            logger:set_process_metadata(maps:without(otel_span:hex_span_ctx_keys(), M));
+        _ ->
+            ok
+    end.