build: optimize Dockerfile with multi-stage build

Co-authored-by: aider (openrouter/openai/o3-mini-high) <aider@aider.chat>

Dockerfile

@@ -1,21 +1,29 @@
-# Use the official Python image as the base image
-FROM python:3.11-slim
-
-# Set the working directory to /app
+# Build stage
+FROM python:3.11-slim AS builder
 WORKDIR /app
 ENV PYTHONPATH=/app
 
-# Install system dependencies
-RUN apt-get update && apt-get install -y \
-    gcc \
-    && rm -rf /var/lib/apt/lists/*
+# Install system dependencies for building
+RUN apt-get update && apt-get install -y gcc && rm -rf /var/lib/apt/lists/*
 
-# Copy requirements and install Python dependencies
+# Copy project files for building
 COPY pyproject.toml .
-RUN pip install --no-cache-dir build
-RUN pip install --no-cache-dir .
+COPY . .
 
-# Install additional dependencies for demo.py
+RUN pip install --no-cache-dir build && python -m build --wheel
+
+# Runtime stage
+FROM python:3.11-slim
+WORKDIR /app
+ENV PYTHONPATH=/app
+
+RUN apt-get update && apt-get install -y libpq-dev && rm -rf /var/lib/apt/lists/*
+
+# Install the built package from builder
+COPY --from=builder /app/dist/*.whl /tmp/
+RUN pip install --no-cache-dir /tmp/*.whl
+
+# Install additional runtime dependencies for demo.py
 RUN pip install --no-cache-dir \
     uvicorn[standard]==0.29.0 \
     python-multipart==0.0.20 \
@@ -28,7 +36,7 @@ RUN pip install --no-cache-dir \
     opentelemetry-instrumentation-httpx==0.55b1 \
     protobuf==5.28.3
 
-# Copy the application code
+# Copy the application code if needed
 COPY ./amqp ./amqp
 COPY ./otdemo ./otdemo
 COPY ./demo.py .
@@ -36,8 +44,6 @@ COPY ./demo.py .
 # Create directory for uploaded files
 RUN mkdir -p /tmp/clevermicro_documents
 
-# Expose the port
 EXPOSE 8000 8001
 
-# Run the FastAPI application
 CMD ["uvicorn", "demo:app", "--host", "0.0.0.0", "--port", "8000"]