Having trouble deploying a FastAPI app that uses MediaPipe and OpenCV.

Stack:

• FastAPI + Uvicorn
• MediaPipe
• opencv-python-headless
• Python 3.10
• Deploying via Dockerfile, Root Directory: /backend

Issues I've hit in order:

1. Nixpacks failed with: undefined variable 'libxcb'
2. Switched to Dockerfile, got: ImportError: libxcb.so.1 cannot open shared object file
3. Found mediapipe was pulling in full opencv-python, overriding headless
4. Fixed by force-uninstalling opencv-python after mediapipe install
5. Now getting: ModuleNotFoundError: No module named 'cv2' at runtime

Current Dockerfile:

FROM python:3.10-slim

WORKDIR /app

RUN apt-get update && apt-get install -y \

libgl1 \

libglib2.0-0 \

libgthread-2.0-0 \

&& rm -rf /var/lib/apt/lists/*

COPY . .

RUN pip install --no-cache-dir mediapipe && \

pip uninstall -y opencv-python opencv-contrib-python || true && \

pip install --no-cache-dir opencv-python-headless && \

pip install --no-cache-dir -r requirements.txt && \

pip uninstall -y opencv-python opencv-contrib-python || true && \

pip install --no-cache-dir opencv-python-headless

ENV PYTHONUNBUFFERED=1

ENV QT_QPA_PLATFORM=offscreen

EXPOSE 8000

CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

requirements.txt:

fastapi

uvicorn

sqlalchemy

pydantic

passlib[bcrypt]

python-jose[cryptography]

python-multipart

mediapipe

opencv-python-headless

numpy

pillow

rich

httpx

Railway settings:

• Builder: Dockerfile
• Root Directory: /backend
• Build Command: empty
• Start Command: empty

Questions:

1. Is mediapipe known to conflict with opencv-python-headless on Railway?
2. Is there a recommended way to deploy MediaPipe on Railway?
3. Could the Root Directory setting be causing COPY to fail silently?

Any help appreciated!