working commit

pullimage.go

@@ -0,0 +1,104 @@
+package repocli
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+const (
+	MediaTypeOIIv1  = "application/vnd.oci.image.index.v1+json"
+	MediatypeDDMLv2 = "application/vnd.docker.distribution.manifest.list.v2+json"
+
+	MediatypeDDMv2 = "application/vnd.docker.distribution.manifest.v2+json"
+	MediaTypeOIMv1 = "application/vnd.oci.image.manifest.v1+json"
+)
+
+type Downloader struct {
+	cli *Client
+}
+
+func NewDownloader(client *Client) *Downloader {
+	return &Downloader{
+		cli: client,
+	}
+}
+
+func (down *Downloader) Pull(ctx context.Context, rawref, dir, os, arch string) error {
+	var err error
+	ref, err := NewReference(rawref)
+	if err != nil {
+		return err
+	}
+	rawrepo := ref.Repo()
+	tag := ref.Tag()
+
+	exist, mime, man, err := down.cli.GetManifest(ctx, rawrepo, tag)
+	if err != nil {
+		return err
+	}
+	if !exist {
+		err = errors.New("Manifest not found")
+		return err
+	}
+
+	if mime == MediaTypeOIIv1 || mime == MediatypeDDMLv2 {
+		var index ocispec.Index
+		err = json.Unmarshal(man, &index)
+		if err != nil {
+			return err
+		}
+		for _, descr := range index.Manifests {
+			if descr.Platform != nil {
+				cond := descr.Platform.Architecture == arch
+				cond = cond && descr.Platform.OS == os
+				if cond {
+					tag = descr.Digest.String()
+				}
+			}
+		}
+	}
+	fmt.Printf("Tag: %s\n", tag)
+	exist, mime, man, err = down.cli.GetManifest(ctx, rawrepo, tag)
+	if err != nil {
+		return err
+	}
+	fmt.Printf("Mime: %s\n", mime)
+	if !exist {
+		err = errors.New("Manifest not found")
+		return err
+	}
+	if mime != MediaTypeOIMv1 && mime != MediatypeDDMv2 {
+		err = errors.New("Unknown manifest media type")
+		return err
+	}
+	var manifest ocispec.Manifest
+	err = json.Unmarshal(man, &manifest)
+	if err != nil {
+		return err
+	}
+	"oci-layout"
+	"index.json"
+
+	layers := make([]ocispec.Descriptor, 0)
+	layers = append(layers, manifest.Config)
+	layers = append(layers, manifest.Layers...)
+	for _, layer := range layers {
+		digest := layer.Digest.String()
+		exist, err := down.cli.GetBlob(ctx, rawrepo, io.Discard, digest)
+		if err != nil {
+			return err
+		}
+		if !exist {
+			err = errors.New("Layer not found")
+			return err
+		}
+		fmt.Printf("Layer type: %s\n", layer.MediaType)
+
+	}
+	return err
+}