func upSlack(api *slack.Client, attachment *multipart.FileHeader) (string, error) {
upFile, err := ioutil.TempFile("", "upSlack_")
defer os.Remove(upFile.Name())
f, err := attachment.Open()
if err != nil {
return "", fmt.Errorf("attached file open error: %v", err)
}
// file save
written, err := io.Copy(upFile, f)
if err != nil {
return "", fmt.Errorf("file save error: %v, written: %d", err, written)
}
fileInfo, err := api.UploadFile(slack.FileUploadParameters{
File: upFile.Name(),
Filename: attachment.Filename,
})
if err != nil {
return "", fmt.Errorf("file upload error: %v", err)
}
return fileInfo.URL, nil
}
