Uploading for to internet site - go

Question

With the below code I can download a file from internet asking with monitoring the downloaded percentage.
How can I do something to upload file to internet as well as monitoring the upload progress. I want to upload executable file at github assets
package main
import (
"fmt"
"io"
"net/http"
"os"
"strings"
"github.com/dustin/go-humanize"
)
// WriteCounter counts the number of bytes written to it. It implements to the io.Writer interface
// and we can pass this into io.TeeReader() which will report progress on each write cycle.
type WriteCounter struct {
Total uint64
}
func (wc *WriteCounter) Write(p []byte) (int, error) {
n := len(p)
wc.Total += uint64(n)
wc.PrintProgress()
return n, nil
}
func (wc WriteCounter) PrintProgress() {
// Clear the line by using a character return to go back to the start and remove
// the remaining characters by filling it with spaces
fmt.Printf("\r%s", strings.Repeat(" ", 35))
// Return again and print current status of download
// We use the humanize package to print the bytes in a meaningful way (e.g. 10 MB)
fmt.Printf("\rDownloading... %s complete", humanize.Bytes(wc.Total))
}
func main() {
fmt.Println("Download Started")
fileUrl := "https://upload.wikimedia.org/wikipedia/commons/d/d6/Wp-w4-big.jpg"
err := DownloadFile("avatar.jpg", fileUrl)
if err != nil {
panic(err)
}
fmt.Println("Download Finished")
}
// DownloadFile will download a url to a local file. It's efficient because it will
// write as it downloads and not load the whole file into memory. We pass an io.TeeReader
// into Copy() to report progress on the download.
func DownloadFile(filepath string, url string) error {
// Create the file, but give it a tmp file extension, this means we won't overwrite a
// file until it's downloaded, but we'll remove the tmp extension once downloaded.
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()
// Create our progress reporter and pass it to be used alongside our writer
counter := &WriteCounter{}
if _, err = io.Copy(out, io.TeeReader(resp.Body, counter)); err != nil {
out.Close()
return err
}
// The progress use the same line so print a new line once it's finished downloading
fmt.Print("\n")
// Close the file without defer so it can happen before Rename()
out.Close()
if err = os.Rename(filepath+".tmp", filepath); err != nil {
return err
}
return nil
}

Answer 1

I just modify your code. It works for my file server.
func UploadFile(filepath string, url string) error {
// Create the file, but give it a tmp file extension, this means we won't overwrite a
// file until it's downloaded, but we'll remove the tmp extension once downloaded.
out, err := os.Open(filepath)
if err != nil {
return err
}
// Create our progress reporter and pass it to be used alongside our writer
counter := &WriteCounter{}
// Get the data
resp, err := http.Post(url, "multipart/form-data", io.TeeReader(out, counter))
if err != nil {
out.Close()
log.Println(err.Error())
return err
}
defer resp.Body.Close()
// The progress use the same line so print a new line once it's finished downloading
fmt.Print("\n")
// Close the file without defer so it can happen before Rename()
out.Close()
return nil
}