1. docker
  2. Commit 081b74b97d0652472293ddaa71f6ab3e2b52c6bd
Browse code

c8d/builder: Store parent in c8d image label

Images built by classic builder will have an additional label (in the
containerd image object, not image config) pointing to a parent of that
image.

This allows to differentiate intermediate images (dangling
images created as a result of a each Dockerfile instruction) from the
final images.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

Paweł Gronowski authored on 2023/09/08 01:00:33
Showing 4 changed files
daemon/containerd/image_builder.go
History View file @ 081b74b
... ... 
@@ -36,6 +36,8 @@ import (
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 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
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 )
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+const imageLabelClassicBuilderParent = "org.mobyproject.image.parent"
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+
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 // GetImageAndReleasableLayer returns an image and releaseable layer for a
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 // reference or ID. Every call to GetImageAndReleasableLayer MUST call
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 // releasableLayer.Release() to prevent leaking of layers.
... ... 
@@ -392,6 +394,8 @@ func (i *ImageService) CreateImage(ctx context.Context, config []byte, parent st
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 	ociImgToCreate := dockerImageToDockerOCIImage(*imgToCreate)
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 	var layers []ocispec.Descriptor
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+
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+	var parentDigest digest.Digest
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 	// if the image has a parent, we need to start with the parents layers descriptors
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 	if parent != "" {
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 		parentDesc, err := i.resolveDescriptor(ctx, parent)
... ... 
@@ -404,6 +408,7 @@ func (i *ImageService) CreateImage(ctx context.Context, config []byte, parent st
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 		}
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 		layers = parentImageManifest.Layers
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+		parentDigest = parentDesc.Digest
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 	}
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 	// get the info for the new layers
... ... 
@@ -443,6 +448,9 @@ func (i *ImageService) CreateImage(ctx context.Context, config []byte, parent st
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 		Name:      danglingImageName(commitManifestDesc.Digest),
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 		Target:    commitManifestDesc,
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 		CreatedAt: time.Now(),
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+		Labels: map[string]string{
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+			imageLabelClassicBuilderParent: parentDigest.String(),
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+		},
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 	}
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 	createdImage, err := i.client.ImageService().Update(ctx, img)
daemon/containerd/image_commit.go
History View file @ 081b74b
... ... 
@@ -106,6 +106,9 @@ func (i *ImageService) CommitImage(ctx context.Context, cc backend.CommitConfig)
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 		Name:      danglingImageName(commitManifestDesc.Digest),
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 		Target:    commitManifestDesc,
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 		CreatedAt: time.Now(),
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+		Labels: map[string]string{
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+			imageLabelClassicBuilderParent: cc.ParentImageID,
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+		},
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 	}
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 	if _, err := i.client.ImageService().Update(ctx, img); err != nil {
daemon/containerd/image_list.go
History View file @ 081b74b
... ... 
@@ -98,8 +98,34 @@ func (i *ImageService) Images(ctx context.Context, opts types.ImageListOptions)
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 	contentStore := i.client.ContentStore()
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 	uniqueImages := map[digest.Digest]images.Image{}
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 	tagsByDigest := map[digest.Digest][]string{}
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+	intermediateImages := map[digest.Digest]struct{}{}
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+
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+	hideIntermediate := !opts.All
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+	if hideIntermediate {
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+		for _, img := range imgs {
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+			parent, ok := img.Labels[imageLabelClassicBuilderParent]
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+			if ok && parent != "" {
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+				dgst, err := digest.Parse(parent)
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+				if err != nil {
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+					log.G(ctx).WithFields(log.Fields{
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+						"error": err,
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+						"value": parent,
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+					}).Warnf("invalid %s label value", imageLabelClassicBuilderParent)
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+				}
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+				intermediateImages[dgst] = struct{}{}
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+			}
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+		}
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+	}
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 	for _, img := range imgs {
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+		isDangling := isDanglingImage(img)
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+
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+		if hideIntermediate && isDangling {
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+			if _, ok := intermediateImages[img.Target.Digest]; ok {
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+				continue
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+			}
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+		}
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+
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 		if !filter(img) {
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 			continue
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 		}
... ... 
@@ -107,7 +133,7 @@ func (i *ImageService) Images(ctx context.Context, opts types.ImageListOptions)
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 		dgst := img.Target.Digest
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 		uniqueImages[dgst] = img
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-		if isDanglingImage(img) {
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+		if isDangling {
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 			continue
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 		}
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daemon/containerd/image_tag.go
History View file @ 081b74b
... ... 
@@ -73,6 +73,17 @@ func (i *ImageService) TagImage(ctx context.Context, imageID image.ID, newTag re
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 		return nil
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 	}
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+	builderLabel, ok := sourceDanglingImg.Labels[imageLabelClassicBuilderParent]
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+	if ok {
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+		newImg.Labels = map[string]string{
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+			imageLabelClassicBuilderParent: builderLabel,
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+		}
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+
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+		if _, err := is.Update(context.Background(), newImg, "labels"); err != nil {
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+			logger.WithError(err).Warnf("failed to set %s label on the newly tagged image", imageLabelClassicBuilderParent)
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+		}
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+	}
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+
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 	// Delete the source dangling image, as it's no longer dangling.
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 	if err := is.Delete(context.Background(), sourceDanglingImg.Name); err != nil {
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 		logger.WithError(err).Warn("unexpected error when deleting dangling image")