Logs from various parts of the application not appearing

[deohgu]

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Example Code

import logging
import sys
from functools import wraps
from typing import Callable, Dict, Optional

from fastapi import BackgroundTasks, Depends, HTTPException, Request, Response, status
from sqlmodel import Session
from starlette.responses import JSONResponse

from app.api.deps.deps import CurrentUser, SessionDep
from app.core.tier_config import ENDPOINT_TO_FEATURE_MAP, EXEMPT_PATHS
from app.models import User
from app.services.quota_service import QuotaService

# Configure logging
logger = logging.getLogger(__name__)

async def rate_limit_dependency(
    request: Request,
    response: Response,
    background_tasks: BackgroundTasks,
    session: SessionDep,
    current_user: CurrentUser,
) -> None:
    """
    FastAPI dependency for rate limiting based on user tier and quota
    """
    # These logs don't appear anywhere
    logger.debug("testing logging")
    logger.info("testing logging")
    logger.warn("testing logging")
    logger.warning("testing logging")
    logging.debug("testing logging")
    logging.info("testing logging")
    logging.warn("testing logging")
    logging.warning("testing logging")
    
    # This doesn't appear either!
    print("===== RATE LIMITING RUNNING =====", file=sys.stderr)

    # The rest of the function works fine - we get 429 errors when expected
    if current_user.is_superuser:
        return
    
    # Code continues...

Description

I'm having a widespread issue with logging in our FastAPI application. Logs from certain parts of the application appear in the console output, while logs from other parts don't show up at all. Even direct print() statements to sys.stderr are not visible from some modules.
For example:

Logs from app/main.py and app/membership_init.py are visible
Logs from API routes, dependencies, and services generally don't appear

What makes this particularly confusing is that I see logs from some modules but not others, despite using the same logging configuration. For instance, this log appears:

2025-03-23 13:27:12,237 - app.main - INFO - Initializing application

But logs from other parts of the application, particularly in the API routes and dependencies, are completely invisible. This happens with logs at all levels (debug, info, warning) and even with direct print statements.
The affected code definitely runs because the functionality works correctly (e.g., rate limits are enforced, routes return expected responses), but no logs appear.

Operating System

macOS, Other

Operating System Details

Running locally in Docker containers with the FastAPI template setup. This is a development environment, not production.

• docker compose watch
• docker compose logs -f backend

Python Version

3.10

Additional Context

• The application is structured using the full-stack-fastapi-template
• Environment is set to "local" in .env file (ENVIRONMENT=local)
• I've confirmed the code is definitely running because functionality works as expected
• I've tried:
  • Setting log level to DEBUG in app/main.py
  • Using direct print statements to stderr
  • Using fully qualified logger names instead of name
  • Setting different log levels