Update Dockerfile

Dockerfile

@@ -1,21 +1,41 @@
-# Use an official Python runtime as a parent image
-FROM python:3.9-slim
+# --- Stage 1: Build Stage ---
+# Use a full Python image to build our dependencies.
+FROM python:3.11-slim as builder
 
-# Set the working directory in the container
+# Set the working directory.
 WORKDIR /app
 
-# Copy the dependencies file to the working directory
-COPY requirements.txt .
+# Install poetry for dependency management.
+# Using poetry is a best practice for managing dependencies.
+RUN pip install poetry
 
-# Install any needed packages specified in requirements.txt
-RUN pip install --no-cache-dir -r requirements.txt
+# Copy only the files needed for dependency installation.
+# This leverages Docker's layer caching.
+COPY pyproject.toml poetry.lock ./
 
-# Copy the rest of the application's code to the working directory
-COPY main.py .
+# Install dependencies.
+# --no-root: Don't install the project itself, only the dependencies.
+# --no-dev: Exclude development dependencies.
+RUN poetry install --no-root --no-dev
 
-# Expose the port the app runs on
+# --- Stage 2: Runtime Stage ---
+# Use a slim Python image for the final container.
+FROM python:3.11-slim
+
+# Set the working directory.
+WORKDIR /app
+
+# Copy the installed dependencies from the builder stage.
+COPY --from=builder /app/.venv /.venv
+
+# Set the PATH to include the virtual environment's bin directory.
+ENV PATH="/app/.venv/bin:$PATH"
+
+# Copy the application code.
+COPY . .
+
+# Expose the port Gunicorn will run on.
 EXPOSE 8000
 
-# Run the application with Uvicorn
-# The host 0.0.0.0 makes the server accessible from outside the container
-CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]
+# The command to run the application using Gunicorn.
+CMD ["gunicorn", "-c", "gunicorn_config.py", "main:app"]