working commit

pkg/repocli/imager.go

@@ -0,0 +1,123 @@
+package repocli
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"os"
+	"path/filepath"
+
+	ocidigest "github.com/opencontainers/go-digest"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+type Imageer interface {
+	WriteManifest(mime string, manifest []byte) error
+	ReadManifest(digest string) (bool, string, []byte, error)
+	WriteBlob(digest string, reader io.Reader) error
+	ReadBlob(digest string, writer io.Writer) error
+}
+
+type Imager struct {
+	index ocispec.Index
+	place string
+}
+
+func NewImager(place string) *Imager {
+	imager := &Imager{
+		index: ocispec.Index{
+			MediaType: MediaTypeOIIv1,
+			Manifests: make([]ocispec.Descriptor, 0),
+		},
+		place: place,
+	}
+	//imager.SchemaVersion = 2
+	return imager
+}
+
+func (ima *Imager) WriteManifest(ctx context.Context, digest, mime string, payload []byte) error {
+	var err error
+	digestobj, err := ocidigest.Parse(digest)
+	if err != nil {
+		return err
+	}
+	var subdir string
+	switch digestobj.Algorithm() {
+	case ocidigest.SHA256:
+		subdir = "sha256"
+	case ocidigest.SHA384:
+		subdir = "sha384"
+	case ocidigest.SHA512:
+		subdir = "sha512"
+	default:
+		err := errors.New("Unknown digest type")
+		return err
+	}
+	dir := filepath.Join(ima.place, subdir)
+	err = os.MkdirAll(dir, 0750)
+	if err != nil {
+		return err
+	}
+	fpath := filepath.Join(dir, digestobj.Encoded())
+	file, err := os.OpenFile(fpath, os.O_CREATE|os.O_WRONLY, 0640)
+	if err != nil {
+		return err
+	}
+	reader := bytes.NewReader(payload)
+	size, err := io.Copy(file, reader)
+	if size != int64(len(payload)) {
+		err = errors.New("Mismatch sizes")
+		return err
+	}
+	descr := ocispec.Descriptor{
+		MediaType: mime,
+		Digest:    digestobj,
+		Size:      size,
+	}
+	ima.index.Manifests = append(ima.index.Manifests, descr)
+	// TODO: flush index
+	return err
+}
+
+func (ima *Imager) WriteLayer(ctx context.Context, digest string, size int64, reader io.Reader) error {
+	var err error
+	digestobj, err := ocidigest.Parse(digest)
+	if err != nil {
+		return err
+	}
+	var subdir string
+	switch digestobj.Algorithm() {
+	case ocidigest.SHA256:
+		subdir = "sha256"
+	case ocidigest.SHA384:
+		subdir = "sha384"
+	case ocidigest.SHA512:
+		subdir = "sha512"
+	default:
+		err := errors.New("Unknown digest type")
+		return err
+	}
+	dir := filepath.Join(ima.place, subdir)
+	err = os.MkdirAll(dir, 0750)
+	if err != nil {
+		return err
+	}
+	fpath := filepath.Join(dir, digestobj.Encoded())
+	file, err := os.OpenFile(fpath, os.O_CREATE|os.O_WRONLY, 0640)
+	if err != nil {
+		return err
+	}
+	verifier := digestobj.Verifier()
+	mw := io.MultiWriter(verifier, file)
+	recsize, err := io.Copy(mw, reader)
+	if size != recsize {
+		err = errors.New("Mismatch sizes")
+		return err
+	}
+	if !verifier.Verified() {
+		err = errors.New("Mismatch digests")
+		return err
+	}
+	return err
+}