Golang Digest.Validate方法代碼示例

// digestPathComponents provides a consistent path breakdown for a given
// digest. For a generic digest, it will be as follows:
//
// 	<algorithm>/<hex digest>
//
// Most importantly, for tarsum, the layout looks like this:
//
// 	tarsum/<version>/<digest algorithm>/<full digest>
//
// If multilevel is true, the first two bytes of the digest will separate
// groups of digest folder. It will be as follows:
//
// 	<algorithm>/<first two bytes of digest>/<full digest>
//
func digestPathComponents(dgst digest.Digest, multilevel bool) ([]string, error) {
	if err := dgst.Validate(); err != nil {
		return nil, err
	}

	algorithm := blobAlgorithmReplacer.Replace(string(dgst.Algorithm()))
	hex := dgst.Hex()
	prefix := []string{algorithm}

	var suffix []string

	if multilevel {
		suffix = append(suffix, hex[:2])
	}

	suffix = append(suffix, hex)

	if tsi, err := digest.ParseTarSum(dgst.String()); err == nil {
		// We have a tarsum!
		version := tsi.Version
		if version == "" {
			version = "v0"
		}

		prefix = []string{
			"tarsum",
			version,
			tsi.Algorithm,
		}
	}

	return append(prefix, suffix...), nil
}

// Stat ensures that the digest is a member of the specified repository and
// forwards the descriptor request to the global blob store. If the media type
// differs for the repository, we override it.
func (rsrbds *repositoryScopedRedisBlobDescriptorService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
	if err := dgst.Validate(); err != nil {
		return distribution.Descriptor{}, err
	}

	conn := rsrbds.upstream.pool.Get()
	defer conn.Close()

	// Check membership to repository first
	member, err := redis.Bool(conn.Do("SISMEMBER", rsrbds.repositoryBlobSetKey(rsrbds.repo), dgst))
	if err != nil {
		return distribution.Descriptor{}, err
	}

	if !member {
		return distribution.Descriptor{}, distribution.ErrBlobUnknown
	}

	upstream, err := rsrbds.upstream.stat(ctx, conn, dgst)
	if err != nil {
		return distribution.Descriptor{}, err
	}

	// We allow a per repository mediatype, let's look it up here.
	mediatype, err := redis.String(conn.Do("HGET", rsrbds.blobDescriptorHashKey(dgst), "mediatype"))
	if err != nil {
		return distribution.Descriptor{}, err
	}

	if mediatype != "" {
		upstream.MediaType = mediatype
	}

	return upstream, nil
}

// SetDescriptor sets the descriptor data for the given digest using a redis
// hash. A hash is used here since we may store unrelated fields about a layer
// in the future.
func (rbds *redisBlobDescriptorService) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
	if err := dgst.Validate(); err != nil {
		return err
	}

	if err := cache.ValidateDescriptor(desc); err != nil {
		return err
	}

	conn := rbds.pool.Get()
	defer conn.Close()

	return rbds.setDescriptor(ctx, conn, dgst, desc)
}

func (mbdc *mapBlobDescriptorCache) SetDescriptor(ctx context.Context, dgst digest.Digest, desc distribution.Descriptor) error {
	if err := dgst.Validate(); err != nil {
		return err
	}

	if err := cache.ValidateDescriptor(desc); err != nil {
		return err
	}

	mbdc.mu.Lock()
	defer mbdc.mu.Unlock()

	mbdc.descriptors[dgst] = desc
	return nil
}

func (mbdc *mapBlobDescriptorCache) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
	if err := dgst.Validate(); err != nil {
		return distribution.Descriptor{}, err
	}

	mbdc.mu.RLock()
	defer mbdc.mu.RUnlock()

	desc, ok := mbdc.descriptors[dgst]
	if !ok {
		return distribution.Descriptor{}, distribution.ErrBlobUnknown
	}

	return desc, nil
}

// MakeImageConfig returns immutable configuration JSON for image based on the
// v1Compatibility object, layer digest and parent StrongID. SHA256() of this
// config is the new image ID (strongID).
func MakeImageConfig(v1Compatibility []byte, layerID, parentID digest.Digest) ([]byte, error) {

	// Detect images created after 1.8.3
	img, err := NewImgJSON(v1Compatibility)
	if err != nil {
		return nil, err
	}
	useFallback := version.Version(img.DockerVersion).LessThan(noFallbackMinVersion)

	if useFallback {
		// Fallback for pre-1.8.3. Calculate base config based on Image struct
		// so that fields with default values added by Docker will use same ID
		logrus.Debugf("Using fallback hash for %v", layerID)

		v1Compatibility, err = json.Marshal(img)
		if err != nil {
			return nil, err
		}
	}

	var c map[string]*json.RawMessage
	if err := json.Unmarshal(v1Compatibility, &c); err != nil {
		return nil, err
	}

	if err := layerID.Validate(); err != nil {
		return nil, fmt.Errorf("invalid layerID: %v", err)
	}

	c["layer_id"] = rawJSON(layerID)

	if parentID != "" {
		if err := parentID.Validate(); err != nil {
			return nil, fmt.Errorf("invalid parentID %v", err)
		}
		c["parent_id"] = rawJSON(parentID)
	}

	delete(c, "id")
	delete(c, "parent")
	delete(c, "Size") // Size is calculated from data on disk and is inconsitent

	return json.Marshal(c)
}

func (rbds *redisBlobDescriptorService) Clear(ctx context.Context, dgst digest.Digest) error {
	if err := dgst.Validate(); err != nil {
		return err
	}

	conn := rbds.pool.Get()
	defer conn.Close()

	// Not atomic in redis <= 2.3
	reply, err := conn.Do("HDEL", rbds.blobDescriptorHashKey(dgst), "digest", "length", "mediatype")
	if err != nil {
		return err
	}

	if reply == 0 {
		return distribution.ErrBlobUnknown
	}

	return nil
}