server.js

import http from 'http';
import mongoose from 'mongoose';
import logger from './middleware/logger.js';
import { DEFAULT_PORT } from './lib/constants.js';
import app from './app.js';

const PORT = process.env.PORT ?? DEFAULT_PORT;
const SERVER = http.createServer(app.callback());

// Gracefully close Mongo connection
const gracefulShutdown = (msg) => {
  logger.info(`Shutdown initiated: ${msg}`);
  mongoose.connection.close(false, () => {
    logger.info('Mongo closed');
    SERVER.close(() => {
      logger.info('Shutting down...');
      process.exit();
    });
  });
};

// Server start
SERVER.listen(PORT, '0.0.0.0', () => {
  logger.info(`Running on port: ${PORT}`);

  // Handle kill commands
  process.on('SIGTERM', gracefulShutdown);

  // Handle interrupts
  process.on('SIGINT', gracefulShutdown);

  // Prevent dirty exit on uncaught exceptions:
  process.on('uncaughtException', gracefulShutdown);

  // Prevent dirty exit on unhandled promise rejection
  process.on('unhandledRejection', gracefulShutdown);
});