Dockerfile

 FROM python:3.9-slim

 # 1) Set working directory
 WORKDIR /app

 # 2) Make /app the home directory so HOME/.streamlit is writable
 ENV HOME=/app

 # 3) Copy code
 COPY . .

 # 4) Install dependencies
 RUN pip install --no-cache-dir -r requirements.txt

-# 5) Pre-create the Streamlit config folder (now under /app/.streamlit)
-RUN mkdir -p /app/.streamlit \
- && printf "[server]\nheadless = true\nport = 7860\n\n" \
-      > /app/.streamlit/config.toml
+# 5) Pre-create the Streamlit config folder and open up permissions
+RUN mkdir -p /app/.streamlit \
+ && printf "[server]\nheadless = true\nport = 7860\n\n" > /app/.streamlit/config.toml \
+ && chmod -R a+rwx /app/.streamlit

 # 6) Expose port and run
 EXPOSE 7860
 CMD ["streamlit", "run", "app.py", "--server.port=7860", "--server.address=0.0.0.0"]