Mongodb Atlas Express.js Error: getaddrinfo ENOTFOUND - mongodb

Question

I want to connect my express app to my mongoDb Atlas cluster.I'm from Iran, and cloud databases are sanctioned for us. I used VPN to bypass it in order to be able to practice.
Is there some coding mistake that I've done or is it because of using VPN?
The error:
(node:9008) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.
connected
events.js:174
throw er; // Unhandled 'error' event
^
Error: getaddrinfo ENOTFOUND
is listening...
at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:56:26)
Emitted 'error' event at:
at GetAddrInfoReqWrap.doListen [as callback] (net.js:1448:12)
at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:56:17)
[nodemon] app crashed - waiting for file changes before starting...
And the code:
database.js
----------------
const mongoDb = require('mongodb');
const MongoClient = mongoDb.MongoClient;
let _db;
const mongoConnect = callback => {
MongoClient.connect(
'mongodb+srv://<someUser>:<somePassword>#<someCluster>-zh1eb.mongodb.net/test?retryWrites=true'
)
.then(client => {
console.log('\nconnected\n');
_db = client.db();
callback();
})
.catch(err => {
console.log('\nerror\n', err);
throw err;
});
};
const getDb = () => {
if (_db) {
return _db;
}
throw 'NO DATABASE FOUND';
};
exports.mongoConnect = mongoConnect;
exports.getDb = getDb;
app.js
------------
...
const mongoConnect = require('./util/database').mongoConnect;
...
mongoConnect(() => {
app.listen(3000, '\nis listening...\n');
});

Answer 1

I found out what was the problem:
mongoConnect(() => {
app.listen(3000, '\nis listening...\n');
});
should actually be
mongoConnect(() => {
app.listen(3000, () => { console.log('\nis listening...\n');});
});
Silly me... :)
For those having such issue:
first check out whether the source of problem is your code or the connection to MongoDb.
That is instead of choosing "connect your application" select "connect with Mongodb Compass".
If the Mongodb Compass could connect and show your cluster, then definitely there is something wrong with your code, esp. how it's coded to connect.