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mirror of https://github.com/distribution/distribution synced 2024-12-25 15:05:51 +01:00
distribution/manifests.go
Sebastiaan van Stijn 0ab7f326e6
replace uses of Descriptor alias
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2024-10-07 13:07:47 +02:00

110 lines
3.5 KiB
Go

package distribution
import (
"context"
"fmt"
"mime"
"github.com/opencontainers/go-digest"
v1 "github.com/opencontainers/image-spec/specs-go/v1"
)
// Manifest represents a registry object specifying a set of
// references and an optional target
type Manifest interface {
// References returns a list of objects which make up this manifest.
// A reference is anything which can be represented by a
// Descriptor. These can consist of layers, resources or other
// manifests.
//
// While no particular order is required, implementations should return
// them from highest to lowest priority. For example, one might want to
// return the base layer before the top layer.
References() []v1.Descriptor
// Payload provides the serialized format of the manifest, in addition to
// the media type.
Payload() (mediaType string, payload []byte, err error)
}
// ManifestService describes operations on manifests.
type ManifestService interface {
// Exists returns true if the manifest exists.
Exists(ctx context.Context, dgst digest.Digest) (bool, error)
// Get retrieves the manifest specified by the given digest
Get(ctx context.Context, dgst digest.Digest, options ...ManifestServiceOption) (Manifest, error)
// Put creates or updates the given manifest returning the manifest digest
Put(ctx context.Context, manifest Manifest, options ...ManifestServiceOption) (digest.Digest, error)
// Delete removes the manifest specified by the given digest. Deleting
// a manifest that doesn't exist will return ErrManifestNotFound
Delete(ctx context.Context, dgst digest.Digest) error
}
// ManifestEnumerator enables iterating over manifests
type ManifestEnumerator interface {
// Enumerate calls ingester for each manifest.
Enumerate(ctx context.Context, ingester func(digest.Digest) error) error
}
// Describable is an interface for descriptors.
//
// Implementations of Describable are generally objects which can be
// described, not simply descriptors.
type Describable interface {
// Descriptor returns the descriptor.
Descriptor() v1.Descriptor
}
// ManifestMediaTypes returns the supported media types for manifests.
func ManifestMediaTypes() (mediaTypes []string) {
for t := range mappings {
if t != "" {
mediaTypes = append(mediaTypes, t)
}
}
return
}
// UnmarshalFunc implements manifest unmarshalling a given MediaType
type UnmarshalFunc func([]byte) (Manifest, v1.Descriptor, error)
var mappings = make(map[string]UnmarshalFunc)
// UnmarshalManifest looks up manifest unmarshal functions based on
// MediaType
func UnmarshalManifest(ctHeader string, p []byte) (Manifest, v1.Descriptor, error) {
// Need to look up by the actual media type, not the raw contents of
// the header. Strip semicolons and anything following them.
var mediaType string
if ctHeader != "" {
var err error
mediaType, _, err = mime.ParseMediaType(ctHeader)
if err != nil {
return nil, v1.Descriptor{}, err
}
}
unmarshalFunc, ok := mappings[mediaType]
if !ok {
unmarshalFunc, ok = mappings[""]
if !ok {
return nil, v1.Descriptor{}, fmt.Errorf("unsupported manifest media type and no default available: %s", mediaType)
}
}
return unmarshalFunc(p)
}
// RegisterManifestSchema registers an UnmarshalFunc for a given schema type. This
// should be called from specific
func RegisterManifestSchema(mediaType string, u UnmarshalFunc) error {
if _, ok := mappings[mediaType]; ok {
return fmt.Errorf("manifest media type registration would overwrite existing: %s", mediaType)
}
mappings[mediaType] = u
return nil
}