Unable to connect to Mongodb Atlas using mongoose

Question

I am trying to connect to a cluster created in Mongodb Atlas using mongoose in node js and I am facing below issues when doing so.

1. When I use the connection string that is given in the Mongo db atlasmongodb+srv://lm_dev_app:<password>@lmdev-q5biw.mongodb.net/test?retryWrites=true&w=majorityI get below error

   { Error: queryTxt EBADNAME lmdev-q5biw.mongodb.net at QueryReqWrap.onresolve [as oncomplete] (dns.js:196:19) errno: 'EBADNAME', code: 'EBADNAME', syscall: 'queryTxt', hostname: 'lmdev-q5biw.mongodb.net'}

I cannot use this connection string in Mongodb Compass as well as I am getting the same error there.

2. If I try to connect using mongodb://lm_dev_app:<password>@lmdev-shard-00-01-q5biw.mongodb.net/test i get below error

   MongooseServerSelectionError: connection to 54.66.221.230:27017 closed

However I am able to connect to each node using Mongodb Compass which eliminates the possibility of my ipaddress not being whitelisted.

Here is the sample code that I am using

const mongoosePromise = mongoose.connect("mongodb://lm_dev_app:<password>@lmdev-shard-00-01-q5biw.mongodb.net/test", {
    useNewUrlParser: true,
    useUnifiedTopology: true,
    replicaSet: "LMDEV"
}, (err) => {
    if (err) {
        console.log(err);
    } else {
        console.log("Successful");
    }
});

Any thoughts on what is happening here.

Answer 1

There are couple of things that I need to highlight here.

1. The default connection string that is shown in MongoDB Atlas seems to be wrong. It shows you:

mongodb+srv://<username>:<password>@<cluster_url>/test?retryWrites=true&w=majority

But I used mongodb://<username>:<password>@<node_url>:27017/ to make it work.
You can also use mongodb://<username>:<password>@<node_url>:27017/admin.

2. Pass ssl:true in the options that we are passing.

3. Finally one of the 3 options can be used to connect to the database:

a.

const mongoosePromise = mongoose.connect("mongodb://lm_dev_app:<password>@lmdev-shard-00-01-q5biw.mongodb.net:27017/", {
        useNewUrlParser: true,
        useUnifiedTopology: true,
        authSource:"admin",
        ssl: true,
    }, (err) => {
        if (err) {
            console.log(err);
        } else {
            console.log("Successful");
        }
    });

b.

const mongoosePromise = mongoose.connect("mongodb://lm_dev_app:<password>@lmdev-shard-00-01-q5biw.mongodb.net:27017/", {
        useNewUrlParser: true,
        useUnifiedTopology: true,
        authSource:"admin",
        ssl: true,
    }, (err) => {
        if (err) {
            console.log(err);
        } else {
            console.log("Successful");
        }
    });

c.

const mongoosePromise = mongoose.connect("mongodb://lm_dev_app:<password>@lmdev-shard-00-01-q5biw.mongodb.net:27017/admin", {
        useNewUrlParser: true,
        useUnifiedTopology: true,
        ssl: true,
    }, (err) => {
        if (err) {
            console.log(err);
        } else {
            console.log("Successful");
        }
    });

---

After having a chat with the Atlas support team I was told that issue in point 1 is due to DNS resolution issue with my service provider. So I have changed my DNS settings to point to a public DNS server.