packer-cn/common/step_download.go

139 lines
3.2 KiB
Go

package common
import (
"encoding/hex"
"fmt"
"github.com/mitchellh/multistep"
"github.com/mitchellh/packer/packer"
"log"
"time"
)
// 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
}
func (s *StepDownload) Run(state map[string]interface{}) multistep.StepAction {
cache := state["cache"].(packer.Cache)
ui := state["ui"].(packer.Ui)
var checksum []byte
if s.Checksum != "" {
var err error
checksum, err = hex.DecodeString(s.Checksum)
if err != nil {
state["error"] = fmt.Errorf("Error parsing checksum: %s", err)
return multistep.ActionHalt
}
}
ui.Say(fmt.Sprintf("Downloading or copying %s", s.Description))
var finalPath string
for _, url := range s.Url {
ui.Message(fmt.Sprintf("Downloading or copying: %s", url))
targetPath := s.TargetPath
if targetPath == "" {
log.Printf("Acquiring lock to download: %s", url)
targetPath = cache.Lock(url)
defer cache.Unlock(url)
}
config := &DownloadConfig{
Url: url,
TargetPath: targetPath,
CopyFile: false,
Hash: HashForType(s.ChecksumType),
Checksum: checksum,
}
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["error"] = err
ui.Error(err.Error())
return multistep.ActionHalt
}
state[s.ResultKey] = finalPath
return multistep.ActionContinue
}
func (s *StepDownload) Cleanup(map[string]interface{}) {}
func (s *StepDownload) download(config *DownloadConfig, state map[string]interface{}) (string, error, bool) {
var path string
ui := state["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[multistep.StateCancelled]; ok {
ui.Say("Interrupt received. Cancelling download...")
return "", nil, false
}
}
}
}