124 lines
3.7 KiB
Go
124 lines
3.7 KiB
Go
package ocischema
|
|
|
|
import (
|
|
"encoding/json"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/docker/distribution"
|
|
"github.com/docker/distribution/manifest"
|
|
"github.com/opencontainers/go-digest"
|
|
"github.com/opencontainers/image-spec/specs-go/v1"
|
|
)
|
|
|
|
var (
|
|
// SchemaVersion provides a pre-initialized version structure for this
|
|
// packages version of the manifest.
|
|
SchemaVersion = manifest.Versioned{
|
|
SchemaVersion: 2, // historical value here.. does not pertain to OCI or docker version
|
|
MediaType: v1.MediaTypeImageManifest,
|
|
}
|
|
)
|
|
|
|
func init() {
|
|
ocischemaFunc := func(b []byte) (distribution.Manifest, distribution.Descriptor, error) {
|
|
m := new(DeserializedManifest)
|
|
err := m.UnmarshalJSON(b)
|
|
if err != nil {
|
|
return nil, distribution.Descriptor{}, err
|
|
}
|
|
|
|
dgst := digest.FromBytes(b)
|
|
return m, distribution.Descriptor{Digest: dgst, Size: int64(len(b)), MediaType: v1.MediaTypeImageManifest}, err
|
|
}
|
|
err := distribution.RegisterManifestSchema(v1.MediaTypeImageManifest, ocischemaFunc)
|
|
if err != nil {
|
|
panic(fmt.Sprintf("Unable to register manifest: %s", err))
|
|
}
|
|
}
|
|
|
|
// Manifest defines a ocischema manifest.
|
|
type Manifest struct {
|
|
manifest.Versioned
|
|
|
|
// Config references the image configuration as a blob.
|
|
Config distribution.Descriptor `json:"config"`
|
|
|
|
// Layers lists descriptors for the layers referenced by the
|
|
// configuration.
|
|
Layers []distribution.Descriptor `json:"layers"`
|
|
|
|
// Annotations contains arbitrary metadata for the image manifest.
|
|
Annotations map[string]string `json:"annotations,omitempty"`
|
|
}
|
|
|
|
// References returns the descriptors of this manifests references.
|
|
func (m Manifest) References() []distribution.Descriptor {
|
|
references := make([]distribution.Descriptor, 0, 1+len(m.Layers))
|
|
references = append(references, m.Config)
|
|
references = append(references, m.Layers...)
|
|
return references
|
|
}
|
|
|
|
// Target returns the target of this manifest.
|
|
func (m Manifest) Target() distribution.Descriptor {
|
|
return m.Config
|
|
}
|
|
|
|
// DeserializedManifest wraps Manifest with a copy of the original JSON.
|
|
// It satisfies the distribution.Manifest interface.
|
|
type DeserializedManifest struct {
|
|
Manifest
|
|
|
|
// canonical is the canonical byte representation of the Manifest.
|
|
canonical []byte
|
|
}
|
|
|
|
// FromStruct takes a Manifest structure, marshals it to JSON, and returns a
|
|
// DeserializedManifest which contains the manifest and its JSON representation.
|
|
func FromStruct(m Manifest) (*DeserializedManifest, error) {
|
|
var deserialized DeserializedManifest
|
|
deserialized.Manifest = m
|
|
|
|
var err error
|
|
deserialized.canonical, err = json.MarshalIndent(&m, "", " ")
|
|
return &deserialized, err
|
|
}
|
|
|
|
// UnmarshalJSON populates a new Manifest struct from JSON data.
|
|
func (m *DeserializedManifest) UnmarshalJSON(b []byte) error {
|
|
m.canonical = make([]byte, len(b))
|
|
// store manifest in canonical
|
|
copy(m.canonical, b)
|
|
|
|
// Unmarshal canonical JSON into Manifest object
|
|
var manifest Manifest
|
|
if err := json.Unmarshal(m.canonical, &manifest); err != nil {
|
|
return err
|
|
}
|
|
|
|
if manifest.MediaType != "" && manifest.MediaType != v1.MediaTypeImageManifest {
|
|
return fmt.Errorf("if present, mediaType in manifest should be '%s' not '%s'",
|
|
v1.MediaTypeImageManifest, manifest.MediaType)
|
|
}
|
|
|
|
m.Manifest = manifest
|
|
|
|
return nil
|
|
}
|
|
|
|
// MarshalJSON returns the contents of canonical. If canonical is empty,
|
|
// marshals the inner contents.
|
|
func (m *DeserializedManifest) MarshalJSON() ([]byte, error) {
|
|
if len(m.canonical) > 0 {
|
|
return m.canonical, nil
|
|
}
|
|
|
|
return nil, errors.New("JSON representation not initialized in DeserializedManifest")
|
|
}
|
|
|
|
// Payload returns the raw content of the manifest. The contents can be used to
|
|
// calculate the content identifier.
|
|
func (m DeserializedManifest) Payload() (string, []byte, error) {
|
|
return v1.MediaTypeImageManifest, m.canonical, nil
|
|
}
|