1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
moby--moby/image/tarexport/load.go
David Calavera 6ee7c94263 Merge pull request #18727 from tonistiigi/partial-load
Add support for partial load
2015-12-18 11:10:55 -08:00

289 lines
6.6 KiB
Go

package tarexport
import (
"encoding/json"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/image"
"github.com/docker/docker/image/v1"
"github.com/docker/docker/layer"
"github.com/docker/docker/pkg/archive"
"github.com/docker/docker/pkg/chrootarchive"
"github.com/docker/docker/pkg/symlink"
"github.com/docker/docker/reference"
)
func (l *tarexporter) Load(inTar io.ReadCloser, outStream io.Writer) error {
tmpDir, err := ioutil.TempDir("", "docker-import-")
if err != nil {
return err
}
defer os.RemoveAll(tmpDir)
if err := chrootarchive.Untar(inTar, tmpDir, nil); err != nil {
return err
}
// read manifest, if no file then load in legacy mode
manifestPath, err := safePath(tmpDir, manifestFileName)
if err != nil {
return err
}
manifestFile, err := os.Open(manifestPath)
if err != nil {
if os.IsNotExist(err) {
return l.legacyLoad(tmpDir, outStream)
}
return manifestFile.Close()
}
defer manifestFile.Close()
var manifest []manifestItem
if err := json.NewDecoder(manifestFile).Decode(&manifest); err != nil {
return err
}
for _, m := range manifest {
configPath, err := safePath(tmpDir, m.Config)
if err != nil {
return err
}
config, err := ioutil.ReadFile(configPath)
if err != nil {
return err
}
img, err := image.NewFromJSON(config)
if err != nil {
return err
}
var rootFS image.RootFS
rootFS = *img.RootFS
rootFS.DiffIDs = nil
if expected, actual := len(m.Layers), len(img.RootFS.DiffIDs); expected != actual {
return fmt.Errorf("invalid manifest, layers length mismatch: expected %q, got %q", expected, actual)
}
for i, diffID := range img.RootFS.DiffIDs {
layerPath, err := safePath(tmpDir, m.Layers[i])
if err != nil {
return err
}
r := rootFS
r.Append(diffID)
newLayer, err := l.ls.Get(r.ChainID())
if err != nil {
newLayer, err = l.loadLayer(layerPath, rootFS)
if err != nil {
return err
}
}
defer layer.ReleaseAndLog(l.ls, newLayer)
if expected, actual := diffID, newLayer.DiffID(); expected != actual {
return fmt.Errorf("invalid diffID for layer %d: expected %q, got %q", i, expected, actual)
}
rootFS.Append(diffID)
}
imgID, err := l.is.Create(config)
if err != nil {
return err
}
for _, repoTag := range m.RepoTags {
named, err := reference.ParseNamed(repoTag)
if err != nil {
return err
}
ref, ok := named.(reference.NamedTagged)
if !ok {
return fmt.Errorf("invalid tag %q", repoTag)
}
l.setLoadedTag(ref, imgID, outStream)
}
}
return nil
}
func (l *tarexporter) loadLayer(filename string, rootFS image.RootFS) (layer.Layer, error) {
rawTar, err := os.Open(filename)
if err != nil {
logrus.Debugf("Error reading embedded tar: %v", err)
return nil, err
}
defer rawTar.Close()
inflatedLayerData, err := archive.DecompressStream(rawTar)
if err != nil {
return nil, err
}
defer inflatedLayerData.Close()
return l.ls.Register(inflatedLayerData, rootFS.ChainID())
}
func (l *tarexporter) setLoadedTag(ref reference.NamedTagged, imgID image.ID, outStream io.Writer) error {
if prevID, err := l.rs.Get(ref); err == nil && prevID != imgID {
fmt.Fprintf(outStream, "The image %s already exists, renaming the old one with ID %s to empty string\n", ref.String(), string(prevID)) // todo: this message is wrong in case of multiple tags
}
if err := l.rs.AddTag(ref, imgID, true); err != nil {
return err
}
return nil
}
func (l *tarexporter) legacyLoad(tmpDir string, outStream io.Writer) error {
legacyLoadedMap := make(map[string]image.ID)
dirs, err := ioutil.ReadDir(tmpDir)
if err != nil {
return err
}
// every dir represents an image
for _, d := range dirs {
if d.IsDir() {
if err := l.legacyLoadImage(d.Name(), tmpDir, legacyLoadedMap); err != nil {
return err
}
}
}
// load tags from repositories file
repositoriesPath, err := safePath(tmpDir, legacyRepositoriesFileName)
if err != nil {
return err
}
repositoriesFile, err := os.Open(repositoriesPath)
if err != nil {
if !os.IsNotExist(err) {
return err
}
return repositoriesFile.Close()
}
defer repositoriesFile.Close()
repositories := make(map[string]map[string]string)
if err := json.NewDecoder(repositoriesFile).Decode(&repositories); err != nil {
return err
}
for name, tagMap := range repositories {
for tag, oldID := range tagMap {
imgID, ok := legacyLoadedMap[oldID]
if !ok {
return fmt.Errorf("invalid target ID: %v", oldID)
}
named, err := reference.WithName(name)
if err != nil {
return err
}
ref, err := reference.WithTag(named, tag)
if err != nil {
return err
}
l.setLoadedTag(ref, imgID, outStream)
}
}
return nil
}
func (l *tarexporter) legacyLoadImage(oldID, sourceDir string, loadedMap map[string]image.ID) error {
if _, loaded := loadedMap[oldID]; loaded {
return nil
}
configPath, err := safePath(sourceDir, filepath.Join(oldID, legacyConfigFileName))
if err != nil {
return err
}
imageJSON, err := ioutil.ReadFile(configPath)
if err != nil {
logrus.Debugf("Error reading json: %v", err)
return err
}
var img struct{ Parent string }
if err := json.Unmarshal(imageJSON, &img); err != nil {
return err
}
var parentID image.ID
if img.Parent != "" {
for {
var loaded bool
if parentID, loaded = loadedMap[img.Parent]; !loaded {
if err := l.legacyLoadImage(img.Parent, sourceDir, loadedMap); err != nil {
return err
}
} else {
break
}
}
}
// todo: try to connect with migrate code
rootFS := image.NewRootFS()
var history []image.History
if parentID != "" {
parentImg, err := l.is.Get(parentID)
if err != nil {
return err
}
rootFS = parentImg.RootFS
history = parentImg.History
}
layerPath, err := safePath(sourceDir, filepath.Join(oldID, legacyLayerFileName))
if err != nil {
return err
}
newLayer, err := l.loadLayer(layerPath, *rootFS)
if err != nil {
return err
}
rootFS.Append(newLayer.DiffID())
h, err := v1.HistoryFromConfig(imageJSON, false)
if err != nil {
return err
}
history = append(history, h)
config, err := v1.MakeConfigFromV1Config(imageJSON, rootFS, history)
if err != nil {
return err
}
imgID, err := l.is.Create(config)
if err != nil {
return err
}
metadata, err := l.ls.Release(newLayer)
layer.LogReleaseMetadata(metadata)
if err != nil {
return err
}
if parentID != "" {
if err := l.is.SetParent(imgID, parentID); err != nil {
return err
}
}
loadedMap[oldID] = imgID
return nil
}
func safePath(base, path string) (string, error) {
return symlink.FollowSymlinkInScope(filepath.Join(base, path), base)
}