From 633f9252b8e066ef7a1a738ddc84c3970379844e Mon Sep 17 00:00:00 2001 From: Derek McGowan Date: Fri, 5 May 2017 10:56:40 -0700 Subject: [PATCH] Use diff ids from image configuration The diff id resolution currently relies on a stored mapping for archive digest to diff id. This mapping could be derived from the image configuration if the image configuration is available. On linux the image config is pulled in parallel and may not be available. On windows, however, it is always pulled first and can be used to supplement the stored mapping for images which may not have this mapping from being side loaded. This becomes useful when combined with side loaded foreign layers. Signed-off-by: Derek McGowan --- distribution/pull_v2.go | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/distribution/pull_v2.go b/distribution/pull_v2.go index 93760a399f..1d6c356b78 100644 --- a/distribution/pull_v2.go +++ b/distribution/pull_v2.go @@ -131,6 +131,7 @@ func (p *v2Puller) pullV2Repository(ctx context.Context, ref reference.Named) (e type v2LayerDescriptor struct { digest digest.Digest + diffID layer.DiffID repoInfo *registry.RepositoryInfo repo distribution.Repository V2MetadataService metadata.V2MetadataService @@ -148,6 +149,9 @@ func (ld *v2LayerDescriptor) ID() string { } func (ld *v2LayerDescriptor) DiffID() (layer.DiffID, error) { + if ld.diffID != "" { + return ld.diffID, nil + } return ld.V2MetadataService.GetDiffID(ld.digest) } @@ -575,6 +579,16 @@ func (p *v2Puller) pullSchema2(ctx context.Context, ref reference.Named, mfst *s if configRootFS == nil { return "", "", errRootFSInvalid } + + if len(descriptors) != len(configRootFS.DiffIDs) { + return "", "", errRootFSMismatch + } + + // Populate diff ids in descriptors to avoid downloading foreign layers + // which have been side loaded + for i := range descriptors { + descriptors[i].(*v2LayerDescriptor).diffID = configRootFS.DiffIDs[i] + } } if p.config.DownloadManager != nil {