uploadprogressbar.go

package main

import(
      pb "gopkg.in/cheggaaa/pb.v1"
    "fmt"
    "os"
    "log"
    "net/http"
    "bytes"
    "time"
    "io"
    "io/ioutil"
    "mime/multipart"
)

func main() {
    path := "path_to/myfile.txt"
    file, err := os.Open(path)
        if err != nil {
            log.Fatal("Error")
        }
        defer file.Close()

    body := &bytes.Buffer{}
    bodyWriter := multipart.NewWriter(body)

    fileWriter, err := bodyWriter.CreateFormFile("file", path)
        if err != nil {
          log.Fatal("Error")  
        }
    io.Copy(fileWriter, file)
    bodyWriter.Close()

    bar := pb.New(body.Len()).SetUnits(pb.U_BYTES).SetRefreshRate(time.Millisecond * 10)
    bar.ShowSpeed = true
    bar.Start()
    xx:=bar.NewProxyReader(body)

    req, e := http.NewRequest("POST", "https://xyz.com/upload", xx)
      if e != nil {
      log.Fatal("Request Error")
    }
    req.Header.Add("Content-Type", bodyWriter.FormDataContentType())
    client := &http.Client{}

    resp, e := client.Do(req)
    bar.Finish()
    if e != nil {
      log.Fatal("Response Error")
    }

    respBody, e := ioutil.ReadAll(resp.Body)
    fmt.Println(string(respBody))

    return
}