index.js

const http = require('http')
const mongoose = require('mongoose')
const config = require('./config/config')
const logger = require('./config/logger')
const app = require('./app')
const socket = require('./socket')

let server
mongoose.connect(config.mongoose.url, config.mongoose.options).then(() => {
  logger.info('Connected to MongoDB')
  server = http.createServer(app)
  socket(server)
  server.listen(config.port, () => {
    logger.info(`Listening to port ${config.port} : http://localhost:${config.port}`)
  })
})

const exitHandler = () => {
  if (server) {
    server.close(() => {
      logger.info('Server closed')
      process.exit(1)
    })
  } else {
    process.exit(1)
  }
}

const unexpectedErrorHandler = (error) => {
  logger.error(error)
  exitHandler()
}

process.on('uncaughtException', unexpectedErrorHandler)
process.on('unhandledRejection', unexpectedErrorHandler)

process.on('SIGTERM', () => {
  logger.info('SIGTERM received')
  if (server) {
    server.close()
  }
})