distribution/manifest/ocischema/builder.go
Cory Snider 671184e910
Remove ManifestBuilder interface
Defining an interface on the implementer side is generally not best
practice in Go code. There is no code in the distribution module which
consumes a ManifestBuilder value so there is no need to define the
interface in the distribution module. Export the concrete
ManifestBuilder types and modify the constructors to return concrete
values.

Co-authored-by: Sebastiaan van Stijn <github@gone.nl>
Signed-off-by: Cory Snider <csnider@mirantis.com>
2024-07-16 11:16:06 +02:00

107 lines
3.1 KiB
Go

package ocischema
import (
"context"
"errors"
"github.com/distribution/distribution/v3"
"github.com/distribution/distribution/v3/manifest"
"github.com/opencontainers/go-digest"
v1 "github.com/opencontainers/image-spec/specs-go/v1"
)
// Builder is a type for constructing manifests.
type Builder struct {
// bs is a BlobService used to publish the configuration blob.
bs distribution.BlobService
// configJSON references
configJSON []byte
// layers is a list of layer descriptors that gets built by successive
// calls to AppendReference.
layers []distribution.Descriptor
// Annotations contains arbitrary metadata relating to the targeted content.
annotations map[string]string
// For testing purposes
mediaType string
}
// NewManifestBuilder is used to build new manifests for the current schema
// version. It takes a BlobService so it can publish the configuration blob
// as part of the Build process, and annotations.
func NewManifestBuilder(bs distribution.BlobService, configJSON []byte, annotations map[string]string) *Builder {
mb := &Builder{
bs: bs,
configJSON: make([]byte, len(configJSON)),
annotations: annotations,
mediaType: v1.MediaTypeImageManifest,
}
copy(mb.configJSON, configJSON)
return mb
}
// SetMediaType assigns the passed mediatype or error if the mediatype is not a
// valid media type for oci image manifests currently: "" or "application/vnd.oci.image.manifest.v1+json"
func (mb *Builder) SetMediaType(mediaType string) error {
if mediaType != "" && mediaType != v1.MediaTypeImageManifest {
return errors.New("invalid media type for OCI image manifest")
}
mb.mediaType = mediaType
return nil
}
// Build produces a final manifest from the given references.
func (mb *Builder) Build(ctx context.Context) (distribution.Manifest, error) {
m := Manifest{
Versioned: manifest.Versioned{
SchemaVersion: 2,
MediaType: mb.mediaType,
},
Layers: make([]distribution.Descriptor, len(mb.layers)),
Annotations: mb.annotations,
}
copy(m.Layers, mb.layers)
configDigest := digest.FromBytes(mb.configJSON)
var err error
m.Config, err = mb.bs.Stat(ctx, configDigest)
switch err {
case nil:
// Override MediaType, since Put always replaces the specified media
// type with application/octet-stream in the descriptor it returns.
m.Config.MediaType = v1.MediaTypeImageConfig
return FromStruct(m)
case distribution.ErrBlobUnknown:
// nop
default:
return nil, err
}
// Add config to the blob store
m.Config, err = mb.bs.Put(ctx, v1.MediaTypeImageConfig, mb.configJSON)
// Override MediaType, since Put always replaces the specified media
// type with application/octet-stream in the descriptor it returns.
m.Config.MediaType = v1.MediaTypeImageConfig
if err != nil {
return nil, err
}
return FromStruct(m)
}
// AppendReference adds a reference to the current ManifestBuilder.
func (mb *Builder) AppendReference(d distribution.Describable) error {
mb.layers = append(mb.layers, d.Descriptor())
return nil
}
// References returns the current references added to this builder.
func (mb *Builder) References() []distribution.Descriptor {
return mb.layers
}