distribution/manifest/ocischema/builder.go
Owen W. Taylor 132abc6de5 Test storing OCI image manifests and indexes with/without a media type
OCI Image manifests and indexes are supported both with and without
an embeded MediaType (the field is reserved according to the spec).
Test storing and retrieving both types from the manifest store.

Signed-off-by: Owen W. Taylor <otaylor@fishsoup.net>
2018-06-19 11:24:25 -04:00

105 lines
3 KiB
Go

package ocischema
import (
"context"
"github.com/docker/distribution"
"github.com/docker/distribution/manifest"
"github.com/opencontainers/go-digest"
"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) distribution.ManifestBuilder {
mb := &Builder{
bs: bs,
configJSON: make([]byte, len(configJSON)),
annotations: annotations,
mediaType: v1.MediaTypeImageManifest,
}
copy(mb.configJSON, configJSON)
return mb
}
// For testing purposes, we want to be able to create an OCI image with
// either an MediaType either empty, or with the OCI image value
func (mb *Builder) SetMediaType(mediaType string) {
if mediaType != "" && mediaType != v1.MediaTypeImageManifest {
panic("Invalid media type for OCI image manifest")
}
mb.mediaType = mediaType
}
// 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
}