daemon/image_history.go

   1 package daemon
   2
   3 import (
   4         "fmt"
   5         "runtime"
   6         "time"
   7
   8         "github.com/docker/distribution/reference"
   9         "github.com/docker/docker/api/types/image"
  10         "github.com/docker/docker/layer"
  11 )
  12
  13 // ImageHistory returns a slice of ImageHistory structures for the specified image
  14 // name by walking the image lineage.
  15 func (daemon *Daemon) ImageHistory(name string) ([]*image.HistoryResponseItem, error) {
  16         start := time.Now()
  17         img, err := daemon.GetImage(name)
  18         if err != nil {
  19                 return nil, err
  20         }
  21
  22         // If the image OS isn't set, assume it's the host OS
  23         platform := img.OS
  24         if platform == "" {
  25                 platform = runtime.GOOS
  26         }
  27
  28         history := []*image.HistoryResponseItem{}
  29
  30         layerCounter := 0
  31         rootFS := *img.RootFS
  32         rootFS.DiffIDs = nil
  33
  34         for _, h := range img.History {
  35                 var layerSize int64
  36
  37                 if !h.EmptyLayer {
  38                         if len(img.RootFS.DiffIDs) <= layerCounter {
  39                                 return nil, fmt.Errorf("too many non-empty layers in History section")
  40                         }
  41
  42                         rootFS.Append(img.RootFS.DiffIDs[layerCounter])
  43                         l, err := daemon.stores[platform].layerStore.Get(rootFS.ChainID())
  44                         if err != nil {
  45                                 return nil, err
  46                         }
  47                         layerSize, err = l.DiffSize()
  48                         layer.ReleaseAndLog(daemon.stores[platform].layerStore, l)
  49                         if err != nil {
  50                                 return nil, err
  51                         }
  52
  53                         layerCounter++
  54                 }
  55
  56                 history = append([]*image.HistoryResponseItem{{
  57                         ID:        "<missing>",
  58                         Created:   h.Created.Unix(),
  59                         CreatedBy: h.CreatedBy,
  60                         Comment:   h.Comment,
  61                         Size:      layerSize,
  62                 }}, history...)
  63         }
  64
  65         // Fill in image IDs and tags
  66         histImg := img
  67         id := img.ID()
  68         for _, h := range history {
  69                 h.ID = id.String()
  70
  71                 var tags []string
  72                 for _, r := range daemon.stores[platform].referenceStore.References(id.Digest()) {
  73                         if _, ok := r.(reference.NamedTagged); ok {
  74                                 tags = append(tags, reference.FamiliarString(r))
  75                         }
  76                 }
  77
  78                 h.Tags = tags
  79
  80                 id = histImg.Parent
  81                 if id == "" {
  82                         break
  83                 }
  84                 histImg, err = daemon.GetImage(id.String())
  85                 if err != nil {
  86                         break
  87                 }
  88         }
  89         imageActions.WithValues("history").UpdateSince(start)
  90         return history, nil
  91 }