moby/graph/pull.go
Derek McGowan f11f3f6203 Remove session backup
The v2 session code will no longer update the indexEndpoint value, therefore it is not necessary to save and restore the value for use with v1.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
2015-01-15 14:05:06 -08:00

561 lines
17 KiB
Go

package graph
import (
"fmt"
"io"
"io/ioutil"
"net"
"net/url"
"os"
"strings"
"time"
log "github.com/Sirupsen/logrus"
"github.com/docker/docker/engine"
"github.com/docker/docker/image"
"github.com/docker/docker/pkg/tarsum"
"github.com/docker/docker/registry"
"github.com/docker/docker/utils"
)
func (s *TagStore) CmdPull(job *engine.Job) engine.Status {
if n := len(job.Args); n != 1 && n != 2 {
return job.Errorf("Usage: %s IMAGE [TAG]", job.Name)
}
var (
localName = job.Args[0]
tag string
sf = utils.NewStreamFormatter(job.GetenvBool("json"))
authConfig = &registry.AuthConfig{}
metaHeaders map[string][]string
)
// Resolve the Repository name from fqn to RepositoryInfo
repoInfo, err := registry.ResolveRepositoryInfo(job, localName)
if err != nil {
return job.Error(err)
}
if len(job.Args) > 1 {
tag = job.Args[1]
}
job.GetenvJson("authConfig", authConfig)
job.GetenvJson("metaHeaders", &metaHeaders)
c, err := s.poolAdd("pull", repoInfo.LocalName+":"+tag)
if err != nil {
if c != nil {
// Another pull of the same repository is already taking place; just wait for it to finish
job.Stdout.Write(sf.FormatStatus("", "Repository %s already being pulled by another client. Waiting.", repoInfo.LocalName))
<-c
return engine.StatusOK
}
return job.Error(err)
}
defer s.poolRemove("pull", repoInfo.LocalName+":"+tag)
log.Debugf("pulling image from host %q with remote name %q", repoInfo.Index.Name, repoInfo.RemoteName)
endpoint, err := repoInfo.GetEndpoint()
if err != nil {
return job.Error(err)
}
r, err := registry.NewSession(authConfig, registry.HTTPRequestFactory(metaHeaders), endpoint, true)
if err != nil {
return job.Error(err)
}
logName := repoInfo.LocalName
if tag != "" {
logName += ":" + tag
}
if len(repoInfo.Index.Mirrors) == 0 && (repoInfo.Index.Official || endpoint.Version == registry.APIVersion2) {
j := job.Eng.Job("trust_update_base")
if err = j.Run(); err != nil {
log.Errorf("error updating trust base graph: %s", err)
}
log.Debugf("pulling v2 repository with local name %q", repoInfo.LocalName)
if err := s.pullV2Repository(job.Eng, r, job.Stdout, repoInfo, tag, sf, job.GetenvBool("parallel")); err == nil {
if err = job.Eng.Job("log", "pull", logName, "").Run(); err != nil {
log.Errorf("Error logging event 'pull' for %s: %s", logName, err)
}
return engine.StatusOK
} else if err != registry.ErrDoesNotExist {
log.Errorf("Error from V2 registry: %s", err)
}
log.Debug("image does not exist on v2 registry, falling back to v1")
}
log.Debugf("pulling v1 repository with local name %q", repoInfo.LocalName)
if err = s.pullRepository(r, job.Stdout, repoInfo, tag, sf, job.GetenvBool("parallel")); err != nil {
return job.Error(err)
}
if err = job.Eng.Job("log", "pull", logName, "").Run(); err != nil {
log.Errorf("Error logging event 'pull' for %s: %s", logName, err)
}
return engine.StatusOK
}
func (s *TagStore) pullRepository(r *registry.Session, out io.Writer, repoInfo *registry.RepositoryInfo, askedTag string, sf *utils.StreamFormatter, parallel bool) error {
out.Write(sf.FormatStatus("", "Pulling repository %s", repoInfo.CanonicalName))
repoData, err := r.GetRepositoryData(repoInfo.RemoteName)
if err != nil {
if strings.Contains(err.Error(), "HTTP code: 404") {
return fmt.Errorf("Error: image %s:%s not found", repoInfo.RemoteName, askedTag)
}
// Unexpected HTTP error
return err
}
log.Debugf("Retrieving the tag list")
tagsList, err := r.GetRemoteTags(repoData.Endpoints, repoInfo.RemoteName, repoData.Tokens)
if err != nil {
log.Errorf("unable to get remote tags: %s", err)
return err
}
for tag, id := range tagsList {
repoData.ImgList[id] = &registry.ImgData{
ID: id,
Tag: tag,
Checksum: "",
}
}
log.Debugf("Registering tags")
// If no tag has been specified, pull them all
var imageId string
if askedTag == "" {
for tag, id := range tagsList {
repoData.ImgList[id].Tag = tag
}
} else {
// Otherwise, check that the tag exists and use only that one
id, exists := tagsList[askedTag]
if !exists {
return fmt.Errorf("Tag %s not found in repository %s", askedTag, repoInfo.CanonicalName)
}
imageId = id
repoData.ImgList[id].Tag = askedTag
}
errors := make(chan error)
layers_downloaded := false
for _, image := range repoData.ImgList {
downloadImage := func(img *registry.ImgData) {
if askedTag != "" && img.Tag != askedTag {
log.Debugf("(%s) does not match %s (id: %s), skipping", img.Tag, askedTag, img.ID)
if parallel {
errors <- nil
}
return
}
if img.Tag == "" {
log.Debugf("Image (id: %s) present in this repository but untagged, skipping", img.ID)
if parallel {
errors <- nil
}
return
}
// ensure no two downloads of the same image happen at the same time
if c, err := s.poolAdd("pull", "img:"+img.ID); err != nil {
if c != nil {
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))
<-c
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))
} else {
log.Debugf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)
}
if parallel {
errors <- nil
}
return
}
defer s.poolRemove("pull", "img:"+img.ID)
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s", img.Tag, repoInfo.CanonicalName), nil))
success := false
var lastErr, err error
var is_downloaded bool
for _, ep := range repoInfo.Index.Mirrors {
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, mirror: %s", img.Tag, repoInfo.CanonicalName, ep), nil))
if is_downloaded, err = s.pullImage(r, out, img.ID, ep, repoData.Tokens, sf); err != nil {
// Don't report errors when pulling from mirrors.
log.Debugf("Error pulling image (%s) from %s, mirror: %s, %s", img.Tag, repoInfo.CanonicalName, ep, err)
continue
}
layers_downloaded = layers_downloaded || is_downloaded
success = true
break
}
if !success {
for _, ep := range repoData.Endpoints {
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, endpoint: %s", img.Tag, repoInfo.CanonicalName, ep), nil))
if is_downloaded, err = s.pullImage(r, out, img.ID, ep, repoData.Tokens, sf); err != nil {
// It's not ideal that only the last error is returned, it would be better to concatenate the errors.
// As the error is also given to the output stream the user will see the error.
lastErr = err
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Error pulling image (%s) from %s, endpoint: %s, %s", img.Tag, repoInfo.CanonicalName, ep, err), nil))
continue
}
layers_downloaded = layers_downloaded || is_downloaded
success = true
break
}
}
if !success {
err := fmt.Errorf("Error pulling image (%s) from %s, %v", img.Tag, repoInfo.CanonicalName, lastErr)
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), err.Error(), nil))
if parallel {
errors <- err
return
}
}
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))
if parallel {
errors <- nil
}
}
if parallel {
go downloadImage(image)
} else {
downloadImage(image)
}
}
if parallel {
var lastError error
for i := 0; i < len(repoData.ImgList); i++ {
if err := <-errors; err != nil {
lastError = err
}
}
if lastError != nil {
return lastError
}
}
for tag, id := range tagsList {
if askedTag != "" && id != imageId {
continue
}
if err := s.Set(repoInfo.LocalName, tag, id, true); err != nil {
return err
}
}
requestedTag := repoInfo.CanonicalName
if len(askedTag) > 0 {
requestedTag = repoInfo.CanonicalName + ":" + askedTag
}
WriteStatus(requestedTag, out, sf, layers_downloaded)
return nil
}
func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint string, token []string, sf *utils.StreamFormatter) (bool, error) {
history, err := r.GetRemoteHistory(imgID, endpoint, token)
if err != nil {
return false, err
}
out.Write(sf.FormatProgress(utils.TruncateID(imgID), "Pulling dependent layers", nil))
// FIXME: Try to stream the images?
// FIXME: Launch the getRemoteImage() in goroutines
layers_downloaded := false
for i := len(history) - 1; i >= 0; i-- {
id := history[i]
// ensure no two downloads of the same layer happen at the same time
if c, err := s.poolAdd("pull", "layer:"+id); err != nil {
log.Debugf("Image (id: %s) pull is already running, skipping: %v", id, err)
<-c
}
defer s.poolRemove("pull", "layer:"+id)
if !s.graph.Exists(id) {
out.Write(sf.FormatProgress(utils.TruncateID(id), "Pulling metadata", nil))
var (
imgJSON []byte
imgSize int
err error
img *image.Image
)
retries := 5
for j := 1; j <= retries; j++ {
imgJSON, imgSize, err = r.GetRemoteImageJSON(id, endpoint, token)
if err != nil && j == retries {
out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
return layers_downloaded, err
} else if err != nil {
time.Sleep(time.Duration(j) * 500 * time.Millisecond)
continue
}
img, err = image.NewImgJSON(imgJSON)
layers_downloaded = true
if err != nil && j == retries {
out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
return layers_downloaded, fmt.Errorf("Failed to parse json: %s", err)
} else if err != nil {
time.Sleep(time.Duration(j) * 500 * time.Millisecond)
continue
} else {
break
}
}
for j := 1; j <= retries; j++ {
// Get the layer
status := "Pulling fs layer"
if j > 1 {
status = fmt.Sprintf("Pulling fs layer [retries: %d]", j)
}
out.Write(sf.FormatProgress(utils.TruncateID(id), status, nil))
layer, err := r.GetRemoteImageLayer(img.ID, endpoint, token, int64(imgSize))
if uerr, ok := err.(*url.Error); ok {
err = uerr.Err
}
if terr, ok := err.(net.Error); ok && terr.Timeout() && j < retries {
time.Sleep(time.Duration(j) * 500 * time.Millisecond)
continue
} else if err != nil {
out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
return layers_downloaded, err
}
layers_downloaded = true
defer layer.Close()
err = s.graph.Register(img,
utils.ProgressReader(layer, imgSize, out, sf, false, utils.TruncateID(id), "Downloading"))
if terr, ok := err.(net.Error); ok && terr.Timeout() && j < retries {
time.Sleep(time.Duration(j) * 500 * time.Millisecond)
continue
} else if err != nil {
out.Write(sf.FormatProgress(utils.TruncateID(id), "Error downloading dependent layers", nil))
return layers_downloaded, err
} else {
break
}
}
}
out.Write(sf.FormatProgress(utils.TruncateID(id), "Download complete", nil))
}
return layers_downloaded, nil
}
func WriteStatus(requestedTag string, out io.Writer, sf *utils.StreamFormatter, layers_downloaded bool) {
if layers_downloaded {
out.Write(sf.FormatStatus("", "Status: Downloaded newer image for %s", requestedTag))
} else {
out.Write(sf.FormatStatus("", "Status: Image is up to date for %s", requestedTag))
}
}
// downloadInfo is used to pass information from download to extractor
type downloadInfo struct {
imgJSON []byte
img *image.Image
tmpFile *os.File
length int64
downloaded bool
err chan error
}
func (s *TagStore) pullV2Repository(eng *engine.Engine, r *registry.Session, out io.Writer, repoInfo *registry.RepositoryInfo, tag string, sf *utils.StreamFormatter, parallel bool) error {
endpoint, err := r.V2RegistryEndpoint(repoInfo.Index)
if err != nil {
return fmt.Errorf("error getting registry endpoint: %s", err)
}
auth, err := r.GetV2Authorization(endpoint, repoInfo.RemoteName, true)
if err != nil {
return fmt.Errorf("error getting authorization: %s", err)
}
var layersDownloaded bool
if tag == "" {
log.Debugf("Pulling tag list from V2 registry for %s", repoInfo.CanonicalName)
tags, err := r.GetV2RemoteTags(endpoint, repoInfo.RemoteName, auth)
if err != nil {
return err
}
for _, t := range tags {
if downloaded, err := s.pullV2Tag(eng, r, out, endpoint, repoInfo, t, sf, parallel, auth); err != nil {
return err
} else if downloaded {
layersDownloaded = true
}
}
} else {
if downloaded, err := s.pullV2Tag(eng, r, out, endpoint, repoInfo, tag, sf, parallel, auth); err != nil {
return err
} else if downloaded {
layersDownloaded = true
}
}
requestedTag := repoInfo.CanonicalName
if len(tag) > 0 {
requestedTag = repoInfo.CanonicalName + ":" + tag
}
WriteStatus(requestedTag, out, sf, layersDownloaded)
return nil
}
func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Writer, endpoint *registry.Endpoint, repoInfo *registry.RepositoryInfo, tag string, sf *utils.StreamFormatter, parallel bool, auth *registry.RequestAuthorization) (bool, error) {
log.Debugf("Pulling tag from V2 registry: %q", tag)
manifestBytes, err := r.GetV2ImageManifest(endpoint, repoInfo.RemoteName, tag, auth)
if err != nil {
return false, err
}
manifest, verified, err := s.verifyManifest(eng, manifestBytes)
if err != nil {
return false, fmt.Errorf("error verifying manifest: %s", err)
}
if err := checkValidManifest(manifest); err != nil {
return false, err
}
if verified {
out.Write(sf.FormatStatus(repoInfo.CanonicalName+":"+tag, "The image you are pulling has been verified"))
} else {
out.Write(sf.FormatStatus(tag, "Pulling from %s", repoInfo.CanonicalName))
}
downloads := make([]downloadInfo, len(manifest.FSLayers))
for i := len(manifest.FSLayers) - 1; i >= 0; i-- {
var (
sumStr = manifest.FSLayers[i].BlobSum
imgJSON = []byte(manifest.History[i].V1Compatibility)
)
img, err := image.NewImgJSON(imgJSON)
if err != nil {
return false, fmt.Errorf("failed to parse json: %s", err)
}
downloads[i].img = img
// Check if exists
if s.graph.Exists(img.ID) {
log.Debugf("Image already exists: %s", img.ID)
continue
}
chunks := strings.SplitN(sumStr, ":", 2)
if len(chunks) < 2 {
return false, fmt.Errorf("expected 2 parts in the sumStr, got %#v", chunks)
}
sumType, checksum := chunks[0], chunks[1]
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Pulling fs layer", nil))
downloadFunc := func(di *downloadInfo) error {
log.Debugf("pulling blob %q to V1 img %s", sumStr, img.ID)
if c, err := s.poolAdd("pull", "img:"+img.ID); err != nil {
if c != nil {
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))
<-c
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))
} else {
log.Debugf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)
}
} else {
defer s.poolRemove("pull", "img:"+img.ID)
tmpFile, err := ioutil.TempFile("", "GetV2ImageBlob")
if err != nil {
return err
}
r, l, err := r.GetV2ImageBlobReader(endpoint, repoInfo.RemoteName, sumType, checksum, auth)
if err != nil {
return err
}
defer r.Close()
// Wrap the reader with the appropriate TarSum reader.
tarSumReader, err := tarsum.NewTarSumForLabel(r, true, sumType)
if err != nil {
return fmt.Errorf("unable to wrap image blob reader with TarSum: %s", err)
}
io.Copy(tmpFile, utils.ProgressReader(ioutil.NopCloser(tarSumReader), int(l), out, sf, false, utils.TruncateID(img.ID), "Downloading"))
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Verifying Checksum", nil))
if finalChecksum := tarSumReader.Sum(nil); !strings.EqualFold(finalChecksum, sumStr) {
return fmt.Errorf("image verification failed: checksum mismatch - expected %q but got %q", sumStr, finalChecksum)
}
out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))
log.Debugf("Downloaded %s to tempfile %s", img.ID, tmpFile.Name())
di.tmpFile = tmpFile
di.length = l
di.downloaded = true
}
di.imgJSON = imgJSON
return nil
}
if parallel {
downloads[i].err = make(chan error)
go func(di *downloadInfo) {
di.err <- downloadFunc(di)
}(&downloads[i])
} else {
err := downloadFunc(&downloads[i])
if err != nil {
return false, err
}
}
}
var layersDownloaded bool
for i := len(downloads) - 1; i >= 0; i-- {
d := &downloads[i]
if d.err != nil {
err := <-d.err
if err != nil {
return false, err
}
}
if d.downloaded {
// if tmpFile is empty assume download and extracted elsewhere
defer os.Remove(d.tmpFile.Name())
defer d.tmpFile.Close()
d.tmpFile.Seek(0, 0)
if d.tmpFile != nil {
err = s.graph.Register(d.img,
utils.ProgressReader(d.tmpFile, int(d.length), out, sf, false, utils.TruncateID(d.img.ID), "Extracting"))
if err != nil {
return false, err
}
// FIXME: Pool release here for parallel tag pull (ensures any downloads block until fully extracted)
}
out.Write(sf.FormatProgress(utils.TruncateID(d.img.ID), "Pull complete", nil))
layersDownloaded = true
} else {
out.Write(sf.FormatProgress(utils.TruncateID(d.img.ID), "Already exists", nil))
}
}
if err = s.Set(repoInfo.LocalName, tag, downloads[0].img.ID, true); err != nil {
return false, err
}
return layersDownloaded, nil
}