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moby--moby/distribution/pull_v1.go
Derek McGowan 3c7676a057
Abstract distribution interfaces from image specific types
Move configurations into a single file.
Abstract download manager in pull config.
Add supports for schema2 only and schema2 type checking.
Add interface for providing push layers.
Abstract image store to generically handle configurations.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>
2016-12-19 10:55:00 -08:00

368 lines
11 KiB
Go

package distribution
import (
"errors"
"fmt"
"io"
"io/ioutil"
"net"
"net/url"
"os"
"strings"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/distribution/registry/client/transport"
"github.com/docker/docker/distribution/metadata"
"github.com/docker/docker/distribution/xfer"
"github.com/docker/docker/dockerversion"
"github.com/docker/docker/image"
"github.com/docker/docker/image/v1"
"github.com/docker/docker/layer"
"github.com/docker/docker/pkg/ioutils"
"github.com/docker/docker/pkg/progress"
"github.com/docker/docker/pkg/stringid"
"github.com/docker/docker/reference"
"github.com/docker/docker/registry"
"golang.org/x/net/context"
)
type v1Puller struct {
v1IDService *metadata.V1IDService
endpoint registry.APIEndpoint
config *ImagePullConfig
repoInfo *registry.RepositoryInfo
session *registry.Session
}
func (p *v1Puller) Pull(ctx context.Context, ref reference.Named) error {
if _, isCanonical := ref.(reference.Canonical); isCanonical {
// Allowing fallback, because HTTPS v1 is before HTTP v2
return fallbackError{err: ErrNoSupport{Err: errors.New("Cannot pull by digest with v1 registry")}}
}
tlsConfig, err := p.config.RegistryService.TLSConfig(p.repoInfo.Index.Name)
if err != nil {
return err
}
// Adds Docker-specific headers as well as user-specified headers (metaHeaders)
tr := transport.NewTransport(
// TODO(tiborvass): was ReceiveTimeout
registry.NewTransport(tlsConfig),
registry.DockerHeaders(dockerversion.DockerUserAgent(ctx), p.config.MetaHeaders)...,
)
client := registry.HTTPClient(tr)
v1Endpoint, err := p.endpoint.ToV1Endpoint(dockerversion.DockerUserAgent(ctx), p.config.MetaHeaders)
if err != nil {
logrus.Debugf("Could not get v1 endpoint: %v", err)
return fallbackError{err: err}
}
p.session, err = registry.NewSession(client, p.config.AuthConfig, v1Endpoint)
if err != nil {
// TODO(dmcgowan): Check if should fallback
logrus.Debugf("Fallback from error: %s", err)
return fallbackError{err: err}
}
if err := p.pullRepository(ctx, ref); err != nil {
// TODO(dmcgowan): Check if should fallback
return err
}
progress.Message(p.config.ProgressOutput, "", p.repoInfo.FullName()+": this image was pulled from a legacy registry. Important: This registry version will not be supported in future versions of docker.")
return nil
}
func (p *v1Puller) pullRepository(ctx context.Context, ref reference.Named) error {
progress.Message(p.config.ProgressOutput, "", "Pulling repository "+p.repoInfo.FullName())
tagged, isTagged := ref.(reference.NamedTagged)
repoData, err := p.session.GetRepositoryData(p.repoInfo)
if err != nil {
if strings.Contains(err.Error(), "HTTP code: 404") {
if isTagged {
return fmt.Errorf("Error: image %s:%s not found", p.repoInfo.RemoteName(), tagged.Tag())
}
return fmt.Errorf("Error: image %s not found", p.repoInfo.RemoteName())
}
// Unexpected HTTP error
return err
}
logrus.Debug("Retrieving the tag list")
var tagsList map[string]string
if !isTagged {
tagsList, err = p.session.GetRemoteTags(repoData.Endpoints, p.repoInfo)
} else {
var tagID string
tagsList = make(map[string]string)
tagID, err = p.session.GetRemoteTag(repoData.Endpoints, p.repoInfo, tagged.Tag())
if err == registry.ErrRepoNotFound {
return fmt.Errorf("Tag %s not found in repository %s", tagged.Tag(), p.repoInfo.FullName())
}
tagsList[tagged.Tag()] = tagID
}
if err != nil {
logrus.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: "",
}
}
layersDownloaded := false
for _, imgData := range repoData.ImgList {
if isTagged && imgData.Tag != tagged.Tag() {
continue
}
err := p.downloadImage(ctx, repoData, imgData, &layersDownloaded)
if err != nil {
return err
}
}
writeStatus(ref.String(), p.config.ProgressOutput, layersDownloaded)
return nil
}
func (p *v1Puller) downloadImage(ctx context.Context, repoData *registry.RepositoryData, img *registry.ImgData, layersDownloaded *bool) error {
if img.Tag == "" {
logrus.Debugf("Image (id: %s) present in this repository but untagged, skipping", img.ID)
return nil
}
localNameRef, err := reference.WithTag(p.repoInfo, img.Tag)
if err != nil {
retErr := fmt.Errorf("Image (id: %s) has invalid tag: %s", img.ID, img.Tag)
logrus.Debug(retErr.Error())
return retErr
}
if err := v1.ValidateID(img.ID); err != nil {
return err
}
progress.Updatef(p.config.ProgressOutput, stringid.TruncateID(img.ID), "Pulling image (%s) from %s", img.Tag, p.repoInfo.FullName())
success := false
var lastErr error
for _, ep := range p.repoInfo.Index.Mirrors {
ep += "v1/"
progress.Updatef(p.config.ProgressOutput, stringid.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, mirror: %s", img.Tag, p.repoInfo.FullName(), ep))
if err = p.pullImage(ctx, img.ID, ep, localNameRef, layersDownloaded); err != nil {
// Don't report errors when pulling from mirrors.
logrus.Debugf("Error pulling image (%s) from %s, mirror: %s, %s", img.Tag, p.repoInfo.FullName(), ep, err)
continue
}
success = true
break
}
if !success {
for _, ep := range repoData.Endpoints {
progress.Updatef(p.config.ProgressOutput, stringid.TruncateID(img.ID), "Pulling image (%s) from %s, endpoint: %s", img.Tag, p.repoInfo.FullName(), ep)
if err = p.pullImage(ctx, img.ID, ep, localNameRef, layersDownloaded); 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
progress.Updatef(p.config.ProgressOutput, stringid.TruncateID(img.ID), "Error pulling image (%s) from %s, endpoint: %s, %s", img.Tag, p.repoInfo.FullName(), ep, err)
continue
}
success = true
break
}
}
if !success {
err := fmt.Errorf("Error pulling image (%s) from %s, %v", img.Tag, p.repoInfo.FullName(), lastErr)
progress.Update(p.config.ProgressOutput, stringid.TruncateID(img.ID), err.Error())
return err
}
return nil
}
func (p *v1Puller) pullImage(ctx context.Context, v1ID, endpoint string, localNameRef reference.Named, layersDownloaded *bool) (err error) {
var history []string
history, err = p.session.GetRemoteHistory(v1ID, endpoint)
if err != nil {
return err
}
if len(history) < 1 {
return fmt.Errorf("empty history for image %s", v1ID)
}
progress.Update(p.config.ProgressOutput, stringid.TruncateID(v1ID), "Pulling dependent layers")
var (
descriptors []xfer.DownloadDescriptor
newHistory []image.History
imgJSON []byte
imgSize int64
)
// Iterate over layers, in order from bottom-most to top-most. Download
// config for all layers and create descriptors.
for i := len(history) - 1; i >= 0; i-- {
v1LayerID := history[i]
imgJSON, imgSize, err = p.downloadLayerConfig(v1LayerID, endpoint)
if err != nil {
return err
}
// Create a new-style config from the legacy configs
h, err := v1.HistoryFromConfig(imgJSON, false)
if err != nil {
return err
}
newHistory = append(newHistory, h)
layerDescriptor := &v1LayerDescriptor{
v1LayerID: v1LayerID,
indexName: p.repoInfo.Index.Name,
endpoint: endpoint,
v1IDService: p.v1IDService,
layersDownloaded: layersDownloaded,
layerSize: imgSize,
session: p.session,
}
descriptors = append(descriptors, layerDescriptor)
}
rootFS := image.NewRootFS()
resultRootFS, release, err := p.config.DownloadManager.Download(ctx, *rootFS, descriptors, p.config.ProgressOutput)
if err != nil {
return err
}
defer release()
config, err := v1.MakeConfigFromV1Config(imgJSON, &resultRootFS, newHistory)
if err != nil {
return err
}
imageID, err := p.config.ImageStore.Put(config)
if err != nil {
return err
}
if p.config.ReferenceStore != nil {
if err := p.config.ReferenceStore.AddTag(localNameRef, imageID, true); err != nil {
return err
}
}
return nil
}
func (p *v1Puller) downloadLayerConfig(v1LayerID, endpoint string) (imgJSON []byte, imgSize int64, err error) {
progress.Update(p.config.ProgressOutput, stringid.TruncateID(v1LayerID), "Pulling metadata")
retries := 5
for j := 1; j <= retries; j++ {
imgJSON, imgSize, err := p.session.GetRemoteImageJSON(v1LayerID, endpoint)
if err != nil && j == retries {
progress.Update(p.config.ProgressOutput, stringid.TruncateID(v1LayerID), "Error pulling layer metadata")
return nil, 0, err
} else if err != nil {
time.Sleep(time.Duration(j) * 500 * time.Millisecond)
continue
}
return imgJSON, imgSize, nil
}
// not reached
return nil, 0, nil
}
type v1LayerDescriptor struct {
v1LayerID string
indexName string
endpoint string
v1IDService *metadata.V1IDService
layersDownloaded *bool
layerSize int64
session *registry.Session
tmpFile *os.File
}
func (ld *v1LayerDescriptor) Key() string {
return "v1:" + ld.v1LayerID
}
func (ld *v1LayerDescriptor) ID() string {
return stringid.TruncateID(ld.v1LayerID)
}
func (ld *v1LayerDescriptor) DiffID() (layer.DiffID, error) {
return ld.v1IDService.Get(ld.v1LayerID, ld.indexName)
}
func (ld *v1LayerDescriptor) Download(ctx context.Context, progressOutput progress.Output) (io.ReadCloser, int64, error) {
progress.Update(progressOutput, ld.ID(), "Pulling fs layer")
layerReader, err := ld.session.GetRemoteImageLayer(ld.v1LayerID, ld.endpoint, ld.layerSize)
if err != nil {
progress.Update(progressOutput, ld.ID(), "Error pulling dependent layers")
if uerr, ok := err.(*url.Error); ok {
err = uerr.Err
}
if terr, ok := err.(net.Error); ok && terr.Timeout() {
return nil, 0, err
}
return nil, 0, xfer.DoNotRetry{Err: err}
}
*ld.layersDownloaded = true
ld.tmpFile, err = ioutil.TempFile("", "GetImageBlob")
if err != nil {
layerReader.Close()
return nil, 0, err
}
reader := progress.NewProgressReader(ioutils.NewCancelReadCloser(ctx, layerReader), progressOutput, ld.layerSize, ld.ID(), "Downloading")
defer reader.Close()
_, err = io.Copy(ld.tmpFile, reader)
if err != nil {
ld.Close()
return nil, 0, err
}
progress.Update(progressOutput, ld.ID(), "Download complete")
logrus.Debugf("Downloaded %s to tempfile %s", ld.ID(), ld.tmpFile.Name())
ld.tmpFile.Seek(0, 0)
// hand off the temporary file to the download manager, so it will only
// be closed once
tmpFile := ld.tmpFile
ld.tmpFile = nil
return ioutils.NewReadCloserWrapper(tmpFile, func() error {
tmpFile.Close()
err := os.RemoveAll(tmpFile.Name())
if err != nil {
logrus.Errorf("Failed to remove temp file: %s", tmpFile.Name())
}
return err
}), ld.layerSize, nil
}
func (ld *v1LayerDescriptor) Close() {
if ld.tmpFile != nil {
ld.tmpFile.Close()
if err := os.RemoveAll(ld.tmpFile.Name()); err != nil {
logrus.Errorf("Failed to remove temp file: %s", ld.tmpFile.Name())
}
ld.tmpFile = nil
}
}
func (ld *v1LayerDescriptor) Registered(diffID layer.DiffID) {
// Cache mapping from this layer's DiffID to the blobsum
ld.v1IDService.Set(ld.v1LayerID, ld.indexName, diffID)
}