func (cli *DogestryCli) getLayerIdsToDownload(fromId remote.ID, imageRoot string, r remote.Remote, client *docker.Client) ([]remote.ID, error) {
toDownload := make([]remote.ID, 0)
err := r.WalkImages(fromId, func(id remote.ID, image docker.Image, err error) error {
fmt.Printf("Examining id '%s' on remote docker host...\n", id.Short())
if err != nil {
return err
}
_, err = client.InspectImage(string(id))
if err == docker.ErrNoSuchImage {
toDownload = append(toDownload, id)
return nil
} else if err != nil {
return err
} else {
fmt.Printf("Docker host already has id '%s', stop scanning.\n", id.Short())
return remote.BreakWalk
}
return nil
})
return toDownload, err
}
func (cli *DogestryCli) pullImage(fromId remote.ID, imageRoot string, r remote.Remote) error {
toDownload, err := cli.getLayerIdsToDownload(fromId, imageRoot, r, cli.Client)
if err != nil {
return err
}
for _, id := range toDownload {
downloadPath := filepath.Join(imageRoot, string(id))
fmt.Printf("Pulling image id '%s' to: %v\n", id.Short(), downloadPath)
err := r.PullImageId(id, downloadPath)
if err != nil {
return err
}
}
return nil
}
func (cli *DogestryCli) downloadImages(r remote.Remote, downloadMap DownloadMap, imageRoot string) error {
pullImagesErrMap := make(map[string]error)
for id, _ := range downloadMap {
downloadPath := filepath.Join(imageRoot, string(id))
fmt.Printf("Pulling image id '%s' to: %v\n", id.Short(), downloadPath)
err := r.PullImageId(id, downloadPath)
if err != nil {
pullImagesErrMap[downloadPath] = err
}
}
if len(pullImagesErrMap) > 0 {
fmt.Printf("Errors pulling images: %v\n", pullImagesErrMap)
return fmt.Errorf("Error downloading files from S3")
}
return nil
}
func (cli *DogestryCli) exportToFiles(image string, r remote.Remote, imageRoot string) error {
imageHistory, err := cli.Client.ImageHistory(image)
if err != nil {
fmt.Printf("Error getting image history: %v\n", err)
return err
}
fmt.Println("Checking layers on remote")
imageID := remote.ID(imageHistory[0].ID)
repoName, repoTag := remote.NormaliseImageName(image)
// Check the remote to see what layers are missing. Only missing Ids will
// need to be saved to disk when exporting the docker image.
missingIds := make(set)
for _, i := range imageHistory {
id := remote.ID(i.ID)
_, err = r.ImageMetadata(id)
if err == nil {
fmt.Printf(" exists : %v\n", id)
} else {
fmt.Printf(" not found: %v\n", id)
missingIds[id] = empty
}
}
if len(missingIds) > 0 {
if err := cli.exportImageToFiles(image, imageRoot, missingIds); err != nil {
return err
}
}
if err := cli.exportMetaDataToFiles(repoName, repoTag, imageID, imageRoot); err != nil {
return err
}
return nil
}
func (cli *DogestryCli) createRepositoriesJsonFile(image, imageRoot string, r remote.Remote) error {
repoName, repoTag := remote.NormaliseImageName(image)
id, err := r.ParseTag(repoName, repoTag)
if err != nil {
return err
} else if id == "" {
return nil
}
reposPath := filepath.Join(imageRoot, "repositories")
reposFile, err := os.Create(reposPath)
if err != nil {
return err
}
defer reposFile.Close()
repositories := map[string]Repository{}
repositories[repoName] = Repository{}
repositories[repoName][repoTag] = string(id)
return json.NewEncoder(reposFile).Encode(&repositories)
}