fixbug: blob for schemav1 could be uncompressed

yyb196 · yyb196 · commit 046536cfb1c8 · 2018-06-08T11:50:54.000+08:00
Signed-off-by: frank yang &lt;yyb196@gmail.com&gt;
diff --git a/archive/compression/compression.go b/archive/compression/compression.go
@@ -43,9 +43,17 @@ var (
 	}
 )
 
+// DecompressReadCloser include the stream after decompress and the compress method detected.
+type DecompressReadCloser interface {
+	io.ReadCloser
+	// GetCompression returns the compress method which is used before decompressing
+	GetCompression() Compression
+}
+
 type readCloserWrapper struct {
 	io.Reader
-	closer func() error
+	compression Compression
+	closer      func() error
 }
 
 func (r *readCloserWrapper) Close() error {
@@ -55,6 +63,10 @@ func (r *readCloserWrapper) Close() error {
 	return nil
 }
 
+func (r *readCloserWrapper) GetCompression() Compression {
+	return r.compression
+}
+
 type writeCloserWrapper struct {
 	io.Writer
 	closer func() error
@@ -84,7 +96,7 @@ func DetectCompression(source []byte) Compression {
 }
 
 // DecompressStream decompresses the archive and returns a ReaderCloser with the decompressed archive.
-func DecompressStream(archive io.Reader) (io.ReadCloser, error) {
+func DecompressStream(archive io.Reader) (DecompressReadCloser, error) {
 	buf := bufioReader32KPool.Get().(*bufio.Reader)
 	buf.Reset(archive)
 	bs, err := buf.Peek(10)
@@ -105,14 +117,14 @@ func DecompressStream(archive io.Reader) (io.ReadCloser, error) {
 	}
 	switch compression := DetectCompression(bs); compression {
 	case Uncompressed:
-		readBufWrapper := &readCloserWrapper{buf, closer}
+		readBufWrapper := &readCloserWrapper{buf, compression, closer}
 		return readBufWrapper, nil
 	case Gzip:
 		gzReader, err := gzip.NewReader(buf)
 		if err != nil {
 			return nil, err
 		}
-		readBufWrapper := &readCloserWrapper{gzReader, closer}
+		readBufWrapper := &readCloserWrapper{gzReader, compression, closer}
 		return readBufWrapper, nil
 	default:
 		return nil, fmt.Errorf("unsupported compression format %s", (&compression).Extension())
diff --git a/remotes/docker/schema1/converter.go b/remotes/docker/schema1/converter.go
@@ -18,7 +18,6 @@ package schema1
 
 import (
 	"bytes"
-	"compress/gzip"
 	"context"
 	"encoding/base64"
 	"encoding/json"
@@ -31,6 +30,7 @@ import (
 
 	"golang.org/x/sync/errgroup"
 
+	"github.com/containerd/containerd/archive/compression"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
@@ -255,8 +255,9 @@ func (c *Converter) fetchBlob(ctx context.Context, desc ocispec.Descriptor) erro
 	log.G(ctx).Debug("fetch blob")
 
 	var (
-		ref  = remotes.MakeRefKey(ctx, desc)
-		calc = newBlobStateCalculator()
+		ref            = remotes.MakeRefKey(ctx, desc)
+		calc           = newBlobStateCalculator()
+		compressMethod = compression.Gzip
 	)
 
 	// size may be unknown, set to zero for content ingest
@@ -280,13 +281,14 @@ func (c *Converter) fetchBlob(ctx context.Context, desc ocispec.Descriptor) erro
 		}
 		defer ra.Close()
 
-		gr, err := gzip.NewReader(content.NewReader(ra))
+		r, err := compression.DecompressStream(content.NewReader(ra))
 		if err != nil {
 			return err
 		}
-		defer gr.Close()
 
-		_, err = io.Copy(calc, gr)
+		compressMethod = r.GetCompression()
+		_, err = io.Copy(calc, r)
+		r.Close()
 		if err != nil {
 			return err
 		}
@@ -303,13 +305,14 @@ func (c *Converter) fetchBlob(ctx context.Context, desc ocispec.Descriptor) erro
 		pr, pw := io.Pipe()
 
 		eg.Go(func() error {
-			gr, err := gzip.NewReader(pr)
+			r, err := compression.DecompressStream(pr)
 			if err != nil {
 				return err
 			}
-			defer gr.Close()
 
-			_, err = io.Copy(calc, gr)
+			compressMethod = r.GetCompression()
+			_, err = io.Copy(calc, r)
+			r.Close()
 			pr.CloseWithError(err)
 			return err
 		})
@@ -333,6 +336,11 @@ func (c *Converter) fetchBlob(ctx context.Context, desc ocispec.Descriptor) erro
 		desc.Size = info.Size
 	}
 
+	if compressMethod == compression.Uncompressed {
+		log.G(ctx).WithField("id", desc.Digest).Debugf("changed media type for uncompressed schema1 layer blob")
+		desc.MediaType = images.MediaTypeDockerSchema2Layer
+	}
+
 	state := calc.State()
 
 	c.mu.Lock()
@@ -342,6 +350,7 @@ func (c *Converter) fetchBlob(ctx context.Context, desc ocispec.Descriptor) erro
 
 	return nil
 }
+
 func (c *Converter) schema1ManifestHistory() ([]ocispec.History, []digest.Digest, error) {
 	if c.pulledManifest == nil {
 		return nil, nil, errors.New("missing schema 1 manifest for conversion")
