'Why "dns.resolve" of NodeJS hangs up when "localhost" is the parameter?

I can understand if I use the dns.resolve() improperly, but hanging up is a starange behaviour. Should not dns.resolve() throw the error if I doing something wrong?

const dns = require("dns").promises;

dns.resolve("localhost").
    then(
      domains => {
        console.log("===========");
        console.log(domains);
      }
    ).
    catch((error) => { console.error(error); });

My version of Node.js is 16.13.0.

node.jsdns


Solution 1:[1]

I think this is explained here: https://nodejs.org/api/dns.html#dnsresolve-dnsresolve-and-dnsreverse

dns.resolve(), dns.resolve*() and dns.reverse() They do not use the same set of configuration files than what dns.lookup() uses. For instance, they do not use the configuration from /etc/hosts.

On my MacOS dns.resolve() correctly returns 127.0.0.1 when I use the default DNS server, when I use 8.8.8.8 it throws this error but does not hang:

Error: queryA ENOTFOUND localhost
    at QueryReqWrap.onresolve [as oncomplete] (internal/dns/promises.js:172:17) {
  errno: undefined,
  code: 'ENOTFOUND',
  syscall: 'queryA',
  hostname: 'localhost'
}

So my guess the problem is caused by a configuration on your system, this GitHub issues contains more information: https://github.com/nodejs/help/issues/2163

Using dns.lookup() correctly returns 127.0.0.1 with default and 8.8.8.8, try it and see how it works.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 Andrei

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