distribution/manifest/schema2/builder.go
Sebastiaan van Stijn 1d33874951
go.mod: change imports to github.com/distribution/distribution/v3
Go 1.13 and up enforce import paths to be versioned if a project
contains a go.mod and has released v2 or up.

The current v2.x branches (and releases) do not yet have a go.mod,
and therefore are still allowed to be imported with a non-versioned
import path (go modules add a `+incompatible` annotation in that case).

However, now that this project has a `go.mod` file, incompatible
import paths will not be accepted by go modules, and attempting
to use code from this repository will fail.

This patch uses `v3` for the import-paths (not `v2`), because changing
import paths itself is a breaking change, which means that  the
next release should increment the "major" version to comply with
SemVer (as go modules dictate).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2021-02-08 18:30:46 +01:00

86 lines
2.5 KiB
Go

package schema2
import (
"context"
"github.com/distribution/distribution/v3"
"github.com/opencontainers/go-digest"
)
// builder is a type for constructing manifests.
type builder struct {
// bs is a BlobService used to publish the configuration blob.
bs distribution.BlobService
// configMediaType is media type used to describe configuration
configMediaType string
// configJSON references
configJSON []byte
// dependencies is a list of descriptors that gets built by successive
// calls to AppendReference. In case of image configuration these are layers.
dependencies []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, configMediaType string, configJSON []byte) distribution.ManifestBuilder {
mb := &builder{
bs: bs,
configMediaType: configMediaType,
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.dependencies)),
}
copy(m.Layers, mb.dependencies)
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 = mb.configMediaType
return FromStruct(m)
case distribution.ErrBlobUnknown:
// nop
default:
return nil, err
}
// Add config to the blob store
m.Config, err = mb.bs.Put(ctx, mb.configMediaType, mb.configJSON)
// Override MediaType, since Put always replaces the specified media
// type with application/octet-stream in the descriptor it returns.
m.Config.MediaType = mb.configMediaType
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.dependencies = append(mb.dependencies, d.Descriptor())
return nil
}
// References returns the current references added to this builder.
func (mb *builder) References() []distribution.Descriptor {
return mb.dependencies
}