How to proxy access mongoDB through ssh tunnel in code?

Question

I'm trying to use atlas mongoDB using ssh tunnel with AWS EC2. The language is Go.

I can guarantee that there will be no problems with EC2. It works when accessing with mongoDB compass.

However, implementing tunneling-connection directly in Go does not work well.

The tunneling code is:

import (
        ...
    "github.com/rgzr/sshtun"
    ...
)
...
    sshTun := sshtun.New(27017, "EC2 IP", 27017)
    sshTun.SetUser("mongoproxy")
    sshTun.SetPassword("...")
    sshTun.SetLocalEndpoint(sshtun.NewTCPEndpoint("127.0.0.1", 27017))
    sshTun.SetRemoteEndpoint(sshtun.NewTCPEndpoint("...mongodb.net", 27017))

    sshTun.SetTunneledConnState(func(tun *sshtun.SSHTun, state *sshtun.TunneledConnState) {
        log.Printf("# TunneledConnState: %+v", state)
    })

    var connected atomic.Bool

    // We set a callback to know when the tunnel is ready
    sshTun.SetConnState(func(tun *sshtun.SSHTun, state sshtun.ConnState) {
        switch state {
        case sshtun.StateStarting:
            log.Printf("STATE is Starting")
        case sshtun.StateStarted:
            connected.Store(true)
            log.Printf("STATE is Started")
        case sshtun.StateStopped:
            connected.Store(false)
            log.Printf("STATE is Stopped")
        }
    })

    go func() {
        for {
            if err := sshTun.Start(context.Background()); err != nil {
                log.Printf("SSH tunnel error: %v", err)
                time.Sleep(time.Second * 10) 
            }
        }
    }()

    for !connected.Load() {
        time.Sleep(time.Second)
    }

       ...

The connection code is as follows:

func NewMongoClientWithTunneling(cfg *config.Config) MongoClient {
    ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
    defer cancel()

    dataSource := fmt.Sprintf(
        "mongodb+srv://%s:%s@%s/%s?retryWrites=true&w=majority",
        cfg.Mongo.User,
        cfg.Mongo.Password,
        "127.0.0.1",
        cfg.Mongo.DBName,
    )

    c, err := mongo.Connect(ctx,
        options.
            Client().
            ApplyURI(dataSource).
            SetMinPoolSize(uint64(cfg.Mongo.Options.MinConnections)).
            SetMaxPoolSize(uint64(cfg.Mongo.Options.MaxConnections)).
            SetMaxConnIdleTime(10*time.Minute).
            SetMonitor(apmmongo.CommandMonitor()),
    )
    if err != nil {
        log.Fatal(err)
    }

    // Check the connection
    if err := c.Ping(ctx, nil); err != nil {
        panic(fmt.Sprintf("Failed to connect to MongoDB: %v", err))
    }
...

When executing the above code, the following error occurs. This is probably because the work done with srv cannot be done on the local host.

2023/08/31 18:37:01 error parsing uri: lookup _mongodb._tcp.127.0.0.1 on 168.126.63.1:53: no such host

I'm wondering what I did wrong and how compass handles this.

I need your help...

The test environment is M2 Pro ventura.