diff --git a/archive/archive.go b/archive/archive.go index 838f8f6e7f..78d5aae18c 100644 --- a/archive/archive.go +++ b/archive/archive.go @@ -3,6 +3,8 @@ package archive import ( "archive/tar" "bytes" + "compress/gzip" + "compress/bzip2" "fmt" "github.com/dotcloud/docker/utils" "io" @@ -59,6 +61,35 @@ func DetectCompression(source []byte) Compression { return Uncompressed } +func DecompressStream(archive io.Reader) (io.Reader, error) { + buf := make([]byte, 10) + totalN := 0 + for totalN < 10 { + n, err := archive.Read(buf[totalN:]) + if err != nil { + if err == io.EOF { + return nil, fmt.Errorf("Tarball too short") + } + return nil, err + } + totalN += n + utils.Debugf("[tar autodetect] n: %d", n) + } + compression := DetectCompression(buf) + wrap := io.MultiReader(bytes.NewReader(buf), archive) + + switch compression { + case Uncompressed: + return wrap, nil + case Gzip: + return gzip.NewReader(wrap) + case Bzip2: + return bzip2.NewReader(wrap), nil + default: + return nil, fmt.Errorf("Unsupported compression format %s", (&compression).Extension()) + } +} + func (compression *Compression) Flag() string { switch *compression { case Bzip2: diff --git a/archive/diff.go b/archive/diff.go index 87457f38c1..72a53de02e 100644 --- a/archive/diff.go +++ b/archive/diff.go @@ -34,6 +34,11 @@ func ApplyLayer(dest string, layer Archive) error { oldmask := syscall.Umask(0) defer syscall.Umask(oldmask) + layer, err := DecompressStream(layer) + if err != nil { + return err + } + tr := tar.NewReader(layer) var dirs []*tar.Header