moby/daemon/containerd/soft_delete.go
Paweł Gronowski b8ba263099
c8d/rmi: Handle explicit dangling name
This isn't something that user should do, but technically the dangling
images exist in the image store and user can pass its name (`moby-dangling@digest`).
Change it so rmi now recognizes that it's actually a dangling image and
doesn't handle it like a regular tagged image.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
2023-10-06 10:20:37 +02:00

84 lines
2.6 KiB
Go

package containerd
import (
"context"
cerrdefs "github.com/containerd/containerd/errdefs"
containerdimages "github.com/containerd/containerd/images"
"github.com/docker/docker/errdefs"
"github.com/opencontainers/go-digest"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/pkg/errors"
)
const imageNameDanglingPrefix = "moby-dangling@"
// softImageDelete deletes the image, making sure that there are other images
// that reference the content of the deleted image.
// If no other image exists, a dangling one is created.
func (i *ImageService) softImageDelete(ctx context.Context, img containerdimages.Image) error {
is := i.client.ImageService()
// If the image already exists, persist it as dangling image
// but only if no other image has the same target.
dgst := img.Target.Digest.String()
imgs, err := is.List(ctx, "target.digest=="+dgst)
if err != nil {
return errdefs.System(errors.Wrapf(err, "failed to check if there are images targeting digest %s", dgst))
}
// From this point explicitly ignore the passed context
// and don't allow to interrupt operation in the middle.
// Create dangling image if this is the last image pointing to this target.
if len(imgs) == 1 {
err = i.ensureDanglingImage(context.Background(), img)
// Error out in case we couldn't persist the old image.
if err != nil {
return errdefs.System(errors.Wrapf(err, "failed to create a dangling image for the replaced image %s with digest %s",
img.Name, img.Target.Digest.String()))
}
}
// Free the target name.
err = is.Delete(context.Background(), img.Name)
if err != nil {
if !cerrdefs.IsNotFound(err) {
return errdefs.System(errors.Wrapf(err, "failed to delete image %s which existed a moment before", img.Name))
}
}
return nil
}
func (i *ImageService) ensureDanglingImage(ctx context.Context, from containerdimages.Image) error {
danglingImage := from
danglingImage.Labels = make(map[string]string)
for k, v := range from.Labels {
switch k {
case containerdimages.AnnotationImageName, ocispec.AnnotationRefName:
// Don't copy name labels.
default:
danglingImage.Labels[k] = v
}
}
danglingImage.Name = danglingImageName(from.Target.Digest)
_, err := i.client.ImageService().Create(context.Background(), danglingImage)
// If it already exists, then just continue.
if cerrdefs.IsAlreadyExists(err) {
return nil
}
return err
}
func danglingImageName(digest digest.Digest) string {
return imageNameDanglingPrefix + digest.String()
}
func isDanglingImage(image containerdimages.Image) bool {
return image.Name == danglingImageName(image.Target.Digest)
}