Dockerfile

FROM python:3.11-slim

ENV HF_HOME=/app/hf_cache \
    PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1

RUN apt-get update && apt-get install -y --no-install-recommends git && rm -rf /var/lib/apt/lists/*

WORKDIR /app
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

RUN mkdir -p /app/hf_cache && chmod -R 777 /app/hf_cache

RUN python - <<'PY' || true
from transformers import AutoTokenizer, AutoModelForSequenceClassification
PRIMARY="cardiffnlp/twitter-roberta-base-sentiment"  # <- stable 3-class
FALLBACK="distilbert-base-uncased-finetuned-sst-2-english"  # binary
for mid in (PRIMARY, FALLBACK):
    try:
        AutoTokenizer.from_pretrained(mid)
        AutoModelForSequenceClassification.from_pretrained(mid)
        print("Cached:", mid)
    except Exception as e:
        print("Cache failed for", mid, "->", e)
PY

COPY app.py .

EXPOSE 7860
CMD bash -lc "uvicorn app:app --host 0.0.0.0 --port ${PORT:-7860}"