Copy a file uploaded with react native background uploader to google cloud

main.go

// UploadAttachmentsEndpoint uses httprouter package..
func UploadAttachmentsEndpoint(res http.ResponseWriter, req *http.Request, _ httprouter.Params) {
	// init your client
	 //...
	 // init your bucket
	storageBucket := client.Bucket(storageBucketName)
	w := storageBucket.Object(name).NewWriter(ctx)
  	w.ContentType = req.Header.Get("Content-Type")


	// ... get the body of the file and copy it in a buffer
	buf, _ := ioutil.ReadAll(req.Body)
	rdr1 := ioutil.NopCloser(bytes.NewBuffer(buf))

	if written, err := io.Copy(w, rdr1); err != nil {
		// handle err if there was any...
		res.Header().Set("500", "Internal Error")
		http.Error(res, "Internal error while uploading. Contact support.", http.StatusInternalServerError)
		return
	}

	// ... do whatever you want with the file now
	if err := w.Close(); err != nil {
	// handle if theres an error while closing 
	}

	// write a response back...
}