Merge pull request #3135 from dmcgowan/archive-importer-docker-types

Compress import blobs in Docker compatibility code

import_test.go

@@ -28,6 +28,7 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/containerd/containerd/archive/compression"
 	"github.com/containerd/containerd/archive/tartest"
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/images/archive"
@@ -289,6 +290,16 @@ func createContent(size int64, seed int64) ([]byte, digest.Digest) {
 	if err != nil {
 		panic(err)
 	}
+	wb := bytes.NewBuffer(nil)
+	cw, err := compression.CompressStream(wb, compression.Gzip)
+	if err != nil {
+		panic(err)
+	}
+
+	if _, err := cw.Write(b); err != nil {
+		panic(err)
+	}
+	b = wb.Bytes()
 	return b, digest.FromBytes(b)
 }