Be able to wait until client SSH tunnel is established

[pmontepagano]

I would like to use chisel client and block or get notified when the SSH tunnel is ready to send/receive data.

I would like to be able to do something like this:

import (
  "context"
  "time"
  chclient "github.com/jpillora/chisel/client"
)

func main(){
  config := chclient.Config(
    KeepAlive: time.Second,
    MaxRetryInterval: time.Second,
    Server: "my-chisel-server",
    Remotes:  []string{"1234:localhost:1234"}
  }

  established := make(chan bool)
  c, err := chclient.NewClient(&config)
  if err != nil {
    log.Fatal(err)
  }
  go func() {
    ctx, cancel = context.WithCancel(context.Background())
    defer cancel()
    if err := c.Start(ctx); err != nil {
      log.Fatal(err)
    }
    
    go func(ctx context.Context) {
      <-ctx.Done()
      // connection failed
      log.Fatal(ctx.Error())
    }(ctx)

    go func() {
      // GetTunnelSSHConn bloquea hasta que está establecida la conexión
      sshCon := c.GetTunnelSSHConn(ctx)
      if (sshCon != nil) {
        log.Printf("Connection established")
        // NOW WE CAN SEND/RECEIVE DATA
       }
    }()

    c.Wait()  // <-- this waits until client is closed or context is cancelled
  }()

  // wait until connection established
  if (<- established) {
    // now I am sure connection has been established and can use tunnel
  }
}

To be able to do this, we would need to expose the internal tunnel inside Client, and use the (private) function getSSH that blocks until connection is established.