// Md5HashValue gets the md5 hash value
func Md5HashValue(log log.T, filePath string) (hash string, err error) {
var exists = false
exists, err = fileutil.LocalFileExist(filePath)
if err != nil || exists == false {
return
}
var f *os.File
f, err = os.Open(filePath)
if err != nil {
log.Error(err)
}
defer f.Close()
hasher := md5.New()
if _, err = io.Copy(hasher, f); err != nil {
log.Error(err)
}
hash = hex.EncodeToString(hasher.Sum(nil))
log.Debugf("Hash=%v, FilePath=%v", hash, filePath)
return
}
// Download is a generic utility which attempts to download smartly.
func Download(log log.T, input DownloadInput) (output DownloadOutput, err error) {
// parse the url
var fileURL *url.URL
fileURL, err = url.Parse(input.SourceURL)
if err != nil {
err = fmt.Errorf("url parsing failed. %v", err)
return
}
// create destination directory
var destinationDir = input.DestinationDirectory
if destinationDir == "" {
destinationDir = appconfig.DownloadRoot
}
// create directory where artifacts are downloaded.
err = fileutil.MakeDirs(destinationDir)
if err != nil {
err = fmt.Errorf("failed to create directory=%v, err=%v", destinationDir, err)
return
}
// process if the url is local file or it has already been downloaded.
var isLocalFile = false
isLocalFile, err = fileutil.LocalFileExist(input.SourceURL)
if err != nil {
err = fmt.Errorf("check for local file exists returned %v", err)
err = nil
}
if isLocalFile == true {
err = fmt.Errorf("source is a local file, skipping download. %v", input.SourceURL)
output.LocalFilePath = input.SourceURL
output.IsUpdated = false
output.IsHashMatched, err = VerifyHash(log, input, output)
} else {
err = fmt.Errorf("source file wasn't found locally, will attempt as web download. %v", input.SourceURL)
// compute the local filename which is hash of url_filename
// Generating a hash_filename will also help against attackers
// from specifying a directory and filename to overwrite any ami/built-in files.
urlHash := md5.Sum([]byte(fileURL.String()))
fileName := filepath.Base(fileURL.String())
output.LocalFilePath = filepath.Join(destinationDir, fmt.Sprintf("%x_%v", urlHash, fileName))
amazonS3URL := s3util.ParseAmazonS3URL(log, fileURL)
if amazonS3URL.IsBucketAndKeyPresent() {
// source is s3
output, err = s3Download(log, amazonS3URL, output.LocalFilePath)
} else {
// simple httphttps download
output, err = httpDownload(log, input.SourceURL, output.LocalFilePath)
}
if err != nil {
return
}
isLocalFile, err = fileutil.LocalFileExist(output.LocalFilePath)
if isLocalFile == true {
output.IsHashMatched, err = VerifyHash(log, input, output)
}
}
return
}
