package schema2 import ( "github.com/docker/distribution" "github.com/docker/distribution/context" "github.com/docker/distribution/digest" ) // 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 } // 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. func NewManifestBuilder(bs distribution.BlobService, configJSON []byte) distribution.ManifestBuilder { mb := &builder{ bs: bs, configJSON: make([]byte, len(configJSON)), } copy(mb.configJSON, configJSON) return mb } // Build produces a final manifest from the given references. func (mb *builder) Build(ctx context.Context) (distribution.Manifest, error) { m := Manifest{ Versioned: SchemaVersion, Layers: make([]distribution.Descriptor, len(mb.layers)), } 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 = MediaTypeConfig return FromStruct(m) case distribution.ErrBlobUnknown: // nop default: return nil, err } // Add config to the blob store m.Config, err = mb.bs.Put(ctx, MediaTypeConfig, mb.configJSON) // Override MediaType, since Put always replaces the specified media // type with application/octet-stream in the descriptor it returns. m.Config.MediaType = MediaTypeConfig 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 }