distribution/manifest/schema1/reference_builder.go
Manish Tomar 3c64ff10bb Fix gometalint errors
Signed-off-by: Manish Tomar <manish.tomar@docker.com>
Signed-off-by: wang yan <wangyan@vmware.com>
2021-03-23 21:03:10 +08:00

98 lines
2.7 KiB
Go

package schema1
import (
"context"
"errors"
"fmt"
"github.com/docker/distribution"
"github.com/docker/distribution/manifest"
"github.com/docker/distribution/reference"
"github.com/docker/libtrust"
"github.com/opencontainers/go-digest"
)
// 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, ref reference.Named, architecture string) distribution.ManifestBuilder {
tag := ""
if tagged, isTagged := ref.(reference.Tagged); isTagged {
tag = tagged.Tag()
}
return &referenceManifestBuilder{
Manifest: Manifest{
Versioned: manifest.Versioned{
SchemaVersion: 1,
},
Name: ref.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,
}
}