Progress Bar

See the example:

package main

import (
	"crypto/rand"
	"io"
	"io/ioutil"
	"log"

	"github.com/cheggaaa/pb/v3"
)

func main() {

	var limit int64 = 1024 * 1024 * 500
	// we will copy 200 Mb from /dev/rand to /dev/null
	reader := io.LimitReader(rand.Reader, limit)
	writer := ioutil.Discard

	// start new bar
	bar := pb.Full.Start64(limit)
	// create proxy reader
	barReader := bar.NewProxyReader(reader)
	// copy from proxy reader
	if _, err := io.Copy(writer, barReader); err != nil {
		log.Fatal(err)
	}
	// finish bar
	bar.Finish()
}

How to resovle the following question?

1. How to get the progress, last speed and remain duration?
2. How to stop the goroutine based on first question?
3. How to stop the upload progress with graceful shutdown?