cannot connect to mongo db when node version > 17

[daniloab]

when using node 17 my application cannot connect to MongoDB

script of example

import mongoose from 'mongoose';

import { MONGO_URI } from './config';

const mongooseOptions = {
  // autoIndex: true,
};

export const connectDatabase = () =>
  new Promise((resolve, reject) => {
    mongoose.connection
      // Reject if an error ocurred when trying to connect to MongoDB
      .on('error', (error) => {
        // eslint-disable-next-line
        console.log('ERROR: Connection to MongoDB failed');
        reject(error);
      })
      // Exit Process if there is no longer a Database Connection
      .on('close', () => {
        // eslint-disable-next-line
        console.log('ERROR: Connection to MongoDB lost');
        process.exit(1);
      })
      // Connected to DB
      .once('open', () => {
        // Display connection information
        const infos = mongoose.connections;
        // eslint-disable-next-line
        infos.map((info) =>
          console.log(`Connected to ${info.host}:${info.port}/${info.name}`),
        );
        // Return sucessfull promisse
        resolve();
      });

    mongoose.connect(MONGO_URI, mongooseOptions);
  });

running this simple connection with your MONGO_URI should return the error below:

For some reason, my environment was on node 17. When I come back to the LTS version 16 returns to works normally.

[IslandRhythms]

import * as mongoose from 'mongoose';


mongoose.connection.on('connected', () => {
    console.log('connected')
});

mongoose.connection.on('error', () => {
    console.log('error')
})


async function run() {
await mongoose.connect('mongodb://localhost:27017');
console.log('done');
}

run();

[sean-daley]

#11066

Looks like the same problem reported there?

Also this seems to be a new intended behavior in node 17 I think.
nodejs/node#40537

[vkarpov15]

@sean-daley is right, #11066 (comment) is the answer. 3 options:

1. Use 127.0.0.1 instead of localhost
2. Modify your /etc/hosts and make sure ::1 localhost is after 127.0.0.1 localhost
3. Start the MongoDB server with ipv6 support. For example, by setting --ipv6 when starting MongoDB server on the command line

Looks like Node v17 changed up the resolution order in nodejs/node#40537, which is why this started happening for you in node v17.

[daniloab]

tks!