Permanent mongoose connection

mongoose.js

var mongoose = require('mongoose')
let dbURI = 'localhost:27017/laimdb'

var timeToWaitOnConnection = 3000 // 3sec
var maxTimeToWaitOnConnection = 30000 // 30sec

mongoose.connection.on('error', function (error) {
  console.error('Error in MongoDb connection: ' + error)
  mongoose.disconnect() // force disconnect since connection.readyState is still 1
})

mongoose.connection.on('disconnected', function () {
  console.log('MongoDB disconnected!')
  setTimeout(connectWithRetry, timeToWaitOnConnection)
})

let connectWithRetry = function () {
  return mongoose.connect(dbURI, { server: { auto_reconnect: true } }, function (err) {
    if (err) {
      console.error('Failed to connect to MongoDb on startup - retrying in ' + (timeToWaitOnConnection / 1000) + ' sec')
      if (timeToWaitOnConnection < maxTimeToWaitOnConnection) {
        timeToWaitOnConnection += 1000
      }
    }
  })
}
connectWithRetry()