FROM node:18-alpine

# Create app directory
WORKDIR /app

# Install dependencies first (layer caching)
COPY package*.json ./
RUN npm install --omit=dev

# Copy application source
COPY . .

# Expose proxy REST API port
EXPOSE 4000

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=15s --retries=3 \
  CMD node -e "require('http').get('http://localhost:4000/health', r => r.statusCode === 200 ? process.exit(0) : process.exit(1)).on('error', () => process.exit(1))"

CMD ["node", "index.js"]