Update Dockerfile

Dockerfile

@@ -1,21 +1,52 @@
+# Dockerfile
+
+# --- Stage 1: Base Image ---
+# Use an official Python slim image as a parent image.
+# Using a specific version (e.g., 3.9) ensures consistency.
+# The 'slim' variant is smaller than the full image.
 FROM python:3.9-slim
 
+# --- Environment Variables ---
+# Prevents Python from writing .pyc files to disc (improves performance in containers)
+ENV PYTHONDONTWRITEBYTECODE 1
+# Ensures that Python output is sent straight to the terminal without being buffered
+ENV PYTHONUNBUFFERED 1
+
+# --- Working Directory ---
+# Set the working directory in the container to /app
 WORKDIR /app
 
-RUN apt-get update && apt-get install -y \
-    build-essential \
-    curl \
-    software-properties-common \
-    git \
-    && rm -rf /var/lib/apt/lists/*
+# --- Create a non-root user ---
+# Create a user group and a user to run the app. This is a security best practice
+# to avoid running the container as root. This will solve the PermissionError.
+RUN addgroup --system streamlit && adduser --system --ingroup streamlit streamlit
+
+# --- Install Dependencies ---
+# Copy the requirements file first to leverage Docker's layer caching.
+# If requirements.txt doesn't change, this layer won't be rebuilt.
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# --- Copy Application Code ---
+# Copy the local code to the container's /app directory
+COPY . .
 
-COPY requirements.txt ./
-COPY src/ ./src/
+# --- Set Ownership ---
+# Change the ownership of the /app directory to the non-root user.
+# This ensures our application has the necessary permissions to read/write in its own directory.
+RUN chown -R streamlit:streamlit /app
 
-RUN pip3 install -r requirements.txt
+# --- Switch to non-root user ---
+# Switch from root to our newly created user.
+USER streamlit
 
+# --- Expose Port ---
+# Expose the port that Streamlit runs on.
 EXPOSE 8501
 
-HEALTHCHECK CMD curl --fail http://localhost:8501/_stcore/health
+# --- Run Application ---
+# The command to run when the container starts.
+# It tells Streamlit to run app.py and listen on all network interfaces,
+# which is necessary for it to be accessible from outside the container.
+CMD ["streamlit", "run", "app.py", "--server.port=8501", "--server.address=0.0.0.0"]
 
-ENTRYPOINT ["streamlit", "run", "src/streamlit_app.py", "--server.port=8501", "--server.address=0.0.0.0"]