Enable Logging with docker-compose?

[YuanhengZ]

Hi everyone,
I have a question that I think should be simple, but I can't seem to get it to work.
I'm using a docker-compose file to start my server, and everything is working well from a functionality perspective. However, I'm not seeing any logs after the litestar-1 | INFO: Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit) message.
I've tried tweaking various settings, but nothing has worked so far.

Here is my dockerfile and compose file, any light on this subject is apperciated.

# Minimal Dockerfile for the API service
FROM python:3.11-slim

ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    APP_PORT=8000

WORKDIR /app

# Install system deps if needed (curl, build tools) - kept minimal
RUN pip install --no-cache-dir --upgrade pip

# Copy only what is necessary
COPY requirements.txt ./requirements.txt
COPY ex ./ex
COPY app.py ./app.py
COPY openapi.yaml ./openapi.yaml
COPY logging.conf ./logging.conf

# Install PyTorch packages with CUDA support from PyTorch index first
RUN pip install --no-cache-dir torch==2.8.0+cu128 torchaudio==2.8.0+cu128 torchvision==0.23.0+cu128 --index-url https://download.pytorch.org/whl/cu128

# Create requirements file without torch-related packages and install other dependencies
RUN grep -v -E "torch.*==" requirements.txt > /tmp/requirements_no_torch.txt && \
    pip install --no-cache-dir -r /tmp/requirements_no_torch.txt

EXPOSE 8000

CMD ["litestar", "run", "--host", "0.0.0.0", "--port", "8000", "--debug"]

services:
  litestar:
    build: .
    image: ex-litestar:dev
    environment:
      - PYTHONUNBUFFERED=1
      - APP_ENV=dev
      - APP_PORT=8000
      - STORAGE_BACKEND=filesystem
      - STORAGE_BASE_PATH=/data/storage
      - REDIS_URL=redis://redis:6379/0
      - PRESIGNED_URL_EXPIRY_SECONDS=900
      - AUTH_MODE=none
    volumes:
      - ./ex:/app/ex:ro
      - ./app.py:/app/app.py:ro
      - ./logging.conf:/app/logging.conf:ro
      - ./openapi.yaml:/app/openapi.yaml:ro
      - ./storage:/data/storage
    ports:
      - "8000:8000"
    depends_on:
      - redis

  celery:
    build: .
    image: ex-celery:dev
    command: ["celery", "-A", "ex.celery_worker:celery_app", "worker", "--loglevel=info"]
    environment:
      - PYTHONUNBUFFERED=1
      - APP_ENV=dev
      - REDIS_URL=redis://redis:6379/0
      - STORAGE_BACKEND=filesystem
      - STORAGE_BASE_PATH=/data/storage
      - API_BASE_URL=http://litestar:8000
    volumes:
      - ./ex:/app/ex:ro
      - ./storage:/data/storage
    depends_on:
      - redis

  redis:
    image: redis:7-alpine
    ports:
      - "6379:6379"
    volumes:
      - redis-data:/data

volumes:
  redis-data:
  # Storage volume for local dev

I have this api to test logging:

@get(path="/healthz", sync_to_thread=False)
def healthz() -> dict[str, str]:
    """Health check endpoint."""
    log.debug("healthz called")
    log.info("Info Level Log Message")
    log.critical("Critical Level Log Message")
    log.warning("Warning Level Log Message")
    log.error("Error Level Log Message")
    return {"status": "ok"}

Failed to see any log. (I do get a {"status": "ok"} from server.)

I am using

fileConfig("logging.conf", disable_existing_loggers=False)
log = logging.getLogger(__name__)

to create logger, and the config file looks like this:

[loggers]
keys=root

[handlers]
keys=consoleHandler,fileHandler

[formatters]
keys=plainFormatter,colorFormatter

[logger_root]
level=DEBUG
handlers=consoleHandler,fileHandler

[handler_consoleHandler]
class=StreamHandler
level=DEBUG
formatter=colorFormatter
args=(sys.stdout,)

[handler_fileHandler]
class=handlers.RotatingFileHandler
level=DEBUG
formatter=plainFormatter
args=('train.log', 'w', 5242880, 0)

[formatter_plainFormatter]
format=%(asctime)s - %(name)s - %(levelname)s - %(message)s (%(pathname)s:%(lineno)d)


[formatter_colorFormatter]
class=colorlog.ColoredFormatter
format=%(asctime)s - %(name)s - %(funcName)s - %(log_color)s%(levelname)s%(reset)s - %(message)s %(bold_blue)s File "%(pathname)s:%(lineno)d"%(reset)s

# Use in program starting point:
# from logging.config import fileConfig
# fileConfig("logging.conf", disable_existing_loggers=False)
# log = logging.getLogger(__name__)

[cclinet]

Have you ever tried to set env variables PYTHONUNBUFFERED=1?