distribution/manifest/schema1/reference_builder.go
Aaron Lehmann 2ff77c00ba Add schema2 manifest support
Add schema2 manifest implementation.

Add a schema2 builder that creates a schema2 manifest from descriptors
and a configuration. It will add the configuration to the blob store if
necessary.

Rename the original schema1 manifest builder to ReferenceBuilder, and
create a ConfigBuilder variant that can build a schema1 manifest from an
image configuration and set of descriptors. This will be used to
translate schema2 manifests to the schema1 format for backward
compatibliity, by adding the descriptors from the existing schema2
manifest to the schema1 builder. It will also be used by engine-side
push code to create schema1 manifests from the new-style image
configration, when necessary to push a schema1 manifest.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2016-01-07 15:26:26 -08:00

92 lines
2.6 KiB
Go

package schema1
import (
"fmt"
"errors"
"github.com/docker/distribution"
"github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/manifest"
"github.com/docker/libtrust"
)
// referenceManifestBuilder is a type for constructing manifests from schema1
// dependencies.
type referenceManifestBuilder struct {
Manifest
pk libtrust.PrivateKey
}
// NewReferenceManifestBuilder is used to build new manifests for the current
// schema version using schema1 dependencies.
func NewReferenceManifestBuilder(pk libtrust.PrivateKey, name, tag, architecture string) distribution.ManifestBuilder {
return &referenceManifestBuilder{
Manifest: Manifest{
Versioned: manifest.Versioned{
SchemaVersion: 1,
},
Name: name,
Tag: tag,
Architecture: architecture,
},
pk: pk,
}
}
func (mb *referenceManifestBuilder) Build(ctx context.Context) (distribution.Manifest, error) {
m := mb.Manifest
if len(m.FSLayers) == 0 {
return nil, errors.New("cannot build manifest with zero layers or history")
}
m.FSLayers = make([]FSLayer, len(mb.Manifest.FSLayers))
m.History = make([]History, len(mb.Manifest.History))
copy(m.FSLayers, mb.Manifest.FSLayers)
copy(m.History, mb.Manifest.History)
return Sign(&m, mb.pk)
}
// AppendReference adds a reference to the current ManifestBuilder
func (mb *referenceManifestBuilder) AppendReference(d distribution.Describable) error {
r, ok := d.(Reference)
if !ok {
return fmt.Errorf("Unable to add non-reference type to v1 builder")
}
// Entries need to be prepended
mb.Manifest.FSLayers = append([]FSLayer{{BlobSum: r.Digest}}, mb.Manifest.FSLayers...)
mb.Manifest.History = append([]History{r.History}, mb.Manifest.History...)
return nil
}
// References returns the current references added to this builder
func (mb *referenceManifestBuilder) References() []distribution.Descriptor {
refs := make([]distribution.Descriptor, len(mb.Manifest.FSLayers))
for i := range mb.Manifest.FSLayers {
layerDigest := mb.Manifest.FSLayers[i].BlobSum
history := mb.Manifest.History[i]
ref := Reference{layerDigest, 0, history}
refs[i] = ref.Descriptor()
}
return refs
}
// Reference describes a manifest v2, schema version 1 dependency.
// An FSLayer associated with a history entry.
type Reference struct {
Digest digest.Digest
Size int64 // if we know it, set it for the descriptor.
History History
}
// Descriptor describes a reference
func (r Reference) Descriptor() distribution.Descriptor {
return distribution.Descriptor{
MediaType: MediaTypeManifestLayer,
Digest: r.Digest,
Size: r.Size,
}
}