packer-cn/common/step_download.go

175 lines
4.3 KiB
Go

package common
import (
"crypto/sha1"
"encoding/hex"
"fmt"
"log"
"time"
"github.com/hashicorp/packer/packer"
"github.com/mitchellh/multistep"
)
// StepDownload downloads a remote file using the download client within
// this package. This step handles setting up the download configuration,
// progress reporting, interrupt handling, etc.
//
// Uses:
// cache packer.Cache
// ui packer.Ui
type StepDownload struct {
// The checksum and the type of the checksum for the download
Checksum string
ChecksumType string
// A short description of the type of download being done. Example:
// "ISO" or "Guest Additions"
Description string
// The name of the key where the final path of the ISO will be put
// into the state.
ResultKey string
// The path where the result should go, otherwise it goes to the
// cache directory.
TargetPath string
// A list of URLs to attempt to download this thing.
Url []string
// Extension is the extension to force for the file that is downloaded.
// Some systems require a certain extension. If this isn't set, the
// extension on the URL is used. Otherwise, this will be forced
// on the downloaded file for every URL.
Extension string
}
func (s *StepDownload) Run(state multistep.StateBag) multistep.StepAction {
cache := state.Get("cache").(packer.Cache)
ui := state.Get("ui").(packer.Ui)
var checksum []byte
if s.Checksum != "" {
var err error
checksum, err = hex.DecodeString(s.Checksum)
if err != nil {
state.Put("error", fmt.Errorf("Error parsing checksum: %s", err))
return multistep.ActionHalt
}
}
ui.Say(fmt.Sprintf("Downloading or copying %s", s.Description))
// First try to use any already downloaded file
// If it fails, proceed to regualar download logic
var downloadConfigs = make([]*DownloadConfig, len(s.Url))
var finalPath string
for i, url := range s.Url {
targetPath := s.TargetPath
if targetPath == "" {
// Determine a cache key. This is normally just the URL but
// if we force a certain extension we hash the URL and add
// the extension to force it.
cacheKey := url
if s.Extension != "" {
hash := sha1.Sum([]byte(url))
cacheKey = fmt.Sprintf(
"%s.%s", hex.EncodeToString(hash[:]), s.Extension)
}
log.Printf("Acquiring lock to download: %s", url)
targetPath = cache.Lock(cacheKey)
defer cache.Unlock(cacheKey)
}
config := &DownloadConfig{
Url: url,
TargetPath: targetPath,
CopyFile: false,
Hash: HashForType(s.ChecksumType),
Checksum: checksum,
UserAgent: "Packer",
}
downloadConfigs[i] = config
if match, _ := NewDownloadClient(config).VerifyChecksum(config.TargetPath); match {
ui.Message(fmt.Sprintf("Found already downloaded, initial checksum matched, no download needed: %s", url))
finalPath = config.TargetPath
break
}
}
if finalPath == "" {
for i, url := range s.Url {
ui.Message(fmt.Sprintf("Downloading or copying: %s", url))
config := downloadConfigs[i]
path, err, retry := s.download(config, state)
if err != nil {
ui.Message(fmt.Sprintf("Error downloading: %s", err))
}
if !retry {
return multistep.ActionHalt
}
if err == nil {
finalPath = path
break
}
}
}
if finalPath == "" {
err := fmt.Errorf("%s download failed.", s.Description)
state.Put("error", err)
ui.Error(err.Error())
return multistep.ActionHalt
}
state.Put(s.ResultKey, finalPath)
return multistep.ActionContinue
}
func (s *StepDownload) Cleanup(multistep.StateBag) {}
func (s *StepDownload) download(config *DownloadConfig, state multistep.StateBag) (string, error, bool) {
var path string
ui := state.Get("ui").(packer.Ui)
download := NewDownloadClient(config)
downloadCompleteCh := make(chan error, 1)
go func() {
var err error
path, err = download.Get()
downloadCompleteCh <- err
}()
progressTicker := time.NewTicker(5 * time.Second)
defer progressTicker.Stop()
for {
select {
case err := <-downloadCompleteCh:
if err != nil {
return "", err, true
}
return path, nil, true
case <-progressTicker.C:
progress := download.PercentProgress()
if progress >= 0 {
ui.Message(fmt.Sprintf("Download progress: %d%%", progress))
}
case <-time.After(1 * time.Second):
if _, ok := state.GetOk(multistep.StateCancelled); ok {
ui.Say("Interrupt received. Cancelling download...")
return "", nil, false
}
}
}
}