How to set DNS server for a single axios get request?

Question

I know I can set the DNS servers in node

dns.setServers([
   '4.4.4.4',
   '[2001:4860:4860::8888]',
]);

But this is set globally and I'm developing a module (dependency) and I don't want to affect the main program (dependent) DNS server

Can I set specific DNS servers only for a single axios request?

const axios = require('axios');

axios.get('https://example.org')
  .then(response => {
    console.log(response.data); // Logs the data returned
  })
  .catch(error => {
    console.error(error.message); // Logs any error that occurs
  });

I checked the request configs for axios and found nothing.

Answer 1

Found the solution

Solution 1

Using the suggestion from @Barmar on the comments, store old DNS servers in a variable and restore them again right after the axios request

const dns = require('dns')
const axios = require('axios')

const oldDnsServers = dns.getServers()

// set new servers
dns.setServers([
   '4.4.4.4',
   '[2001:4860:4860::8888]'
])

axios.get('https://example.org')
  .then(response => {
    console.log(response.data) // Logs the data returned
  })
  .catch(error => {
    console.error(error.message) // Logs any error that occurs
  })

dns.setServers(oldDnsServers)

Solution 2

A more elegant solution is to use the lookup function and dns.Resolver class

const axios = require('axios')
const dns = require('dns')

const resolver = new dns.Resolver()
resolver.setServers([
   '4.4.4.4',
   '[2001:4860:4860::8888]'
])

const customLookup = (hostname, options, callback) => {
  // Resolve both IPv4 and IPv6 addresses
  if (options.family === 6) {
    resolver.resolve6(hostname, (err, addresses) => {
      if (err) return callback(err)
      callback(null, addresses[0], 6)
    })
  } else {
    resolver.resolve4(hostname, (err, addresses) => {
      if (err) return callback(err)
      callback(null, addresses[0], 4)
    })
  }
}

axios.get('https://example.org', { lookup: customLookup })
  .then(response => {
    console.log(response.data); // Logs the data returned
  })
  .catch(error => {
    console.error(error.message); // Logs any error that occurs
  })