From 39499c9f294baba7a46b21713d2a64109322c229 Mon Sep 17 00:00:00 2001
From: 0206pdh <0206pdh@naver.com>
Date: Fri, 3 Jul 2026 12:29:58 +0900
Subject: [PATCH] fix(logging): read user_email from span attributes, not a
 ContextVar
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이전 PR(#94)의 ContextVar 방식이 실제로는 동작하지 않는 버그였다.
get_current_user()는 동기 함수(def)라 FastAPI가 스레드풀에서 실행하는데,
anyio.to_thread.run_sync는 contextvars.copy_context()로 복사본을 만들어
그 안에서 실행하므로 ContextVar.set()이 원래 요청 컨텍스트로 전파되지
않는다. 즉 이미지를 새로 배포해도 로그에 user_email이 절대 찍히지 않았다.

span.set_attribute()는 이미 값이 채워진 span 객체 자체를 참조로 공유하기
때문에 스레드 경계와 무관하게 작동한다 (user.id/user.email 트레이스 검색이
이미 되던 이유). 그래서 별도 ContextVar 없이 포매터에서 현재 span의
attributes를 직접 읽도록 변경.
---
 app/api/dependencies.py |  2 --
 app/core/logging.py     | 17 ++++++++---------
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/app/api/dependencies.py b/app/api/dependencies.py
index d188e37..434401a 100644
--- a/app/api/dependencies.py
+++ b/app/api/dependencies.py
@@ -9,7 +9,6 @@
 from app.core.db import get_db_session
 from app.core.enums import UserStatus
 from app.core.config import get_settings
-from app.core.logging import set_request_user_email
 from app.core.security import decode_access_token
 from app.repositories.user import UserRepository
 from app.schemas.auth import TokenPayload, UserRead
@@ -52,7 +51,6 @@ def get_current_user(
     span = trace.get_current_span()
     span.set_attribute("user.id", str(resolved.id))
     span.set_attribute("user.email", resolved.email)
-    set_request_user_email(resolved.email)
     return resolved
 
 
diff --git a/app/core/logging.py b/app/core/logging.py
index 70d3b52..2109946 100644
--- a/app/core/logging.py
+++ b/app/core/logging.py
@@ -4,17 +4,9 @@
 
 import json
 import logging
-from contextvars import ContextVar
 
 from opentelemetry import trace
 
-_user_email_var: ContextVar[str] = ContextVar('user_email', default='')
-
-
-def set_request_user_email(email: str) -> None:
-    _user_email_var.set(email)
-
-
 _SKIP_ATTRS = frozenset((
     "name", "msg", "args", "levelname", "levelno",
     "pathname", "filename", "module", "exc_info",
@@ -41,7 +33,14 @@ def format(self, record: logging.LogRecord) -> str:
             "span_id": format(ctx.span_id, "016x") if ctx.is_valid else "",
         }
 
-        user_email = _user_email_var.get()
+        # Read off the span's attributes rather than a ContextVar: the
+        # dependency that resolves the user runs in FastAPI's threadpool
+        # (sync def), and contextvars.copy_context() there means any
+        # ContextVar.set() inside it never propagates back to the request's
+        # context. The span object itself is shared by reference across
+        # that boundary, so attribute mutations on it are visible everywhere.
+        attributes = getattr(span, "attributes", None) or {}
+        user_email = attributes.get("user.email")
         if user_email:
             entry["user_email"] = user_email