How to connect to mongoDB via ssl using .crt file in Go

I am trying to connect to a mongo database hosted in azure using the .crt file.

I am successfully able to connect from my linux machine terminal using command:

mongo mongodb://username:password@prod-replicaset-0.com:27017,prod-replicaset-1.com:27017,prod-replicaset-2.com:27017/ --tls --tlsCAFile rootca.crt --tlsAllowInvalidCertificates

I am also able to connect from mongo UI client like robo3T by setting "Use SSL protocol" and using Auth Mechanism as "SCRAM-SHA-256". [If I set Auth Mechanism to any other value, results in Authentication Failure]

But I am not able to connect to that database in Go lang code.

Here is a sample of code I am using:

package main

import (
    "crypto/tls"
    "crypto/x509"
    "io/ioutil"
    "log"
    "net"

    "github.com/globalsign/mgo"
)

func InitMongo() error {

    rootCerts := x509.NewCertPool()
    ca, err := ioutil.ReadFile("./rootca.crt")
    if err != nil {
        log.Fatalf("failed to read file : %s", err.Error())
        return err
    }

    success := rootCerts.AppendCertsFromPEM(ca)
    if !success {
        log.Printf("rootcert failed")
    }

    connStr := "mongodb://username:password@prod-replicaset-0.com:27017,prod-replicaset-1.com:27017,prod-replicaset-2.com:27017/?ssl=true"

    dbDialInfo, err := mgo.ParseURL(connStr)
    if err != nil {
        log.Fatal("unable to parse url - " + err.Error())
    }

    dbDialInfo.DialServer = func(addr *mgo.ServerAddr) (net.Conn, error) {
        return tls.Dial("tcp", addr.String(), &tls.Config{
            RootCAs:            rootCerts,
            InsecureSkipVerify: true,
        })
    }

    // dbDialInfo.Mechanism = "SCRAM-SHA-256"

    _session, err := mgo.DialWithInfo(dbDialInfo)
    if err != nil {
        log.Fatalf("failed to creating db session : %s", err.Error())
        return err
    }

    log.Printf("Created session - %v", _session)

    return nil
}

When I run this code, I get error: failed to creating db session : "server returned error on SASL authentication step: Authentication failed."

If I set [dbDialInfo.Mechanism = "SCRAM-SHA-256"] before creating session, I get error: failed to creating db session : "SASL support not enabled during build (-tags sasl)"

Please let me know what is causing this issue, how can I connect to the database. Currently I am using "github.com/globalsign/mgo", if it required to use any other library, that's totally fine for me. I just want to get connected to the db.

rootca.crt file looks something like:

Thank you.

Solution

After researching a lot, I was not able to find a way to connect to mongodb using .crt file using globalsign library.

However I was successfully able to do this using mongo-driver library. here connection string can be of format:

mongodb://user:password@replicaset-0.com:27017,replicaset-1.com:27017,replicaset-2.com:27017/?ssl=true&tlsCAFile=./ca.crt&tlsCertificateKeyFile=./ca.pem&authSource=admin&replicaSet=replicaset

Sample code:

import (
    "context"
    "log"
    "os"

    // "github.com/globalsign/mgo"
    mgo "go.mongodb.org/mongo-driver/mongo"

    mongoOptions "go.mongodb.org/mongo-driver/mongo/options"
)
func InitMongo() (error) {
    
    connStr := os.Getenv("MONGODB_CONN_STR")
    dbName := os.Getenv("MONGODB_DATABASE")

    clientOpts := mongoOptions.Client().ApplyURI(connStr)
    if err := clientOpts.Validate(); err != nil {
        log.Print("unable to parse url")
        log.Fatal(err)
    }
    client, err := mgo.Connect(context.TODO(), clientOpts)
    if err != nil {
        log.Print("unable to connect into database")
        log.Fatal(err)
    }
    if err := client.Ping(context.TODO(), nil); err != nil {
        log.Print("database ping failed")
        log.Fatal(err)
    }

    //client.Database(dbName)

    return nil
}