dns-info.js

var dns = require('native-dns')
var Promise = require('bluebird')
var _ = require('lodash')
var defaults = {
  server: {
    address: '8.8.8.8',
    port: 53,
    type: 'udp'
  },
  timeout: 2000
}

module.exports = function fetchDnsInfo(param) {
  var config = parseConfig(param, defaults)
  var allTypes = Object.keys(dns.consts.NAME_TO_QTYPE).map(function(type) {
    return new Promise(function(resolve, reject) {
      dns.Request({
        question: dns.Question({
          name: config.domain,
          type: type
        }),
        server: config.server,
        timeout: config.timeout
      }).on('timeout', function() {
        reject('Timeout in fetching DNS info.')
      }).on('message', function(err, res) {
        resolve(err || res)
      }).send()
    })
  })
  return Promise.reduce(allTypes, function(result, response) {
    if (response.answer.length) {
      var ANY = 255
      if (response.question[0].type === ANY) {
        result.byAny = response.answer.map(function(entry) {
          entry.type = dns.consts.QTYPE_TO_NAME[entry.type]
          return _(entry).omit('name', 'class').value()
        })
      } else {
        var questionType = dns.consts.QTYPE_TO_NAME[response.question[0].type]
        var data = response.answer.map(function(entry) {
          return _(entry).omit('type', 'name', 'class').value()
        })
        result.byTypes.push({type: questionType, data: data})
      }
    }
    return result
  }, {domain: config.domain, byTypes: [], byAny: undefined})
}

function parseConfig(param, defaults) {
  if (typeof param === 'string') {
    return _.assign({}, defaults, {domain: param})
  } else {
    return _.assign({}, defaults, param)
  }
}