Dockerfile

# ============================================================================
# QuantX Trading API - Dockerfile
# Multi-stage build for optimized production image
# ============================================================================

# -----------------------------------------------------------------------------
# Stage 1: Builder - Install dependencies
# -----------------------------------------------------------------------------
FROM python:3.12-slim as builder

WORKDIR /app

# Install build dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    gcc \
    libpq-dev \
    && rm -rf /var/lib/apt/lists/*

# Create virtual environment
RUN python -m venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"

# Install Python dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir --upgrade pip && \
    pip install --no-cache-dir -r requirements.txt

# -----------------------------------------------------------------------------
# Stage 2: Runtime - Lean production image
# -----------------------------------------------------------------------------
FROM python:3.12-slim as runtime

WORKDIR /app

# Install runtime dependencies only
RUN apt-get update && apt-get install -y --no-install-recommends \
    libpq5 \
    curl \
    && rm -rf /var/lib/apt/lists/* \
    && useradd --create-home --shell /bin/bash quantx

# Copy virtual environment from builder
COPY --from=builder /opt/venv /opt/venv
ENV PATH="/opt/venv/bin:$PATH"

# Copy application code
COPY --chown=quantx:quantx . .

# Switch to non-root user
USER quantx

# Expose the API port
EXPOSE 8000

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
    CMD curl -f http://localhost:8000/health/simple || exit 1

# Run the application
# Using gunicorn with a single uvicorn worker for production
# - 1 worker to maintain consistent in-memory state (order books, event bus)
# - UvicornWorker for async support
# Railway provides PORT env var, default to 8000 for local development
CMD ["sh", "-c", "gunicorn api.main_v2:app -w 1 -k uvicorn.workers.UvicornWorker --bind 0.0.0.0:${PORT:-8000}"]