go downloader with progress bar

main.go

package main

import (
	"io"
	"net/http"
	"os"

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

type progress struct {
	Total int
	Pb    *pb.ProgressBar
}

func (p *progress) Write(data []byte) (int, error) {
	n := len(data)
	p.Pb.Add(int(n))
	return n, nil

}

func downloadFile(filepath string, url string) error {
	out, err := os.Create(filepath + ".tmp")
	if err != nil {
		return err
	}

	// Get the data
	resp, err := http.Get(url)
	if err != nil {
		out.Close()
		return err
	}

	defer resp.Body.Close()

	bar := pb.Simple.New(int(resp.ContentLength))
	bar.Set(pb.Bytes, true)
	bar.Set(pb.SIBytesPrefix, true)

	var p = &progress{
		Pb: bar.Start(),
	}

	if _, err = io.Copy(out, io.TeeReader(resp.Body, p)); err != nil {
		out.Close()
		return err
	}

	if err = os.Rename(filepath+".tmp", filepath); err != nil {
		return err
	}

	return nil
}

func main() {
	if err := downloadFile("okteto.exe", "https://github.com/okteto/okteto/releases/download/1.8.16/okteto.exe"); err != nil {
		panic(err)
	}
}