backport tar handling from #2410 (#2702)

Signed-off-by: Michael Henriksen <[email protected]>

cmd/cdi-cloner/clone-source.go

@@ -146,12 +146,38 @@ func validateMount() {
 }
 
 func newTarReader(preallocation bool) (io.ReadCloser, error) {
-	args := "cv"
+	excludeMap := map[string]struct{}{
+		"lost+found": struct{}{},
+	}
+
+	args := []string{"/usr/bin/tar", "cv"}
 	if !preallocation {
 		// -S is used to handle sparse files. It can only be used when preallocation is not requested
-		args = "S" + args
+		args = append(args, "-S")
 	}
-	cmd := exec.Command("/usr/bin/tar", args, ".")
+
+	files, err := os.ReadDir(mountPoint)
+	if err != nil {
+		return nil, err
+	}
+
+	var tarFiles []string
+	for _, f := range files {
+		if _, ok := excludeMap[f.Name()]; ok {
+			continue
+		}
+		tarFiles = append(tarFiles, f.Name())
+	}
+
+	if len(tarFiles) > 0 {
+		args = append(args, tarFiles...)
+	} else {
+		args = append(args, "--files-from", "/dev/null")
+	}
+
+	klog.Infof("Executing %+v", args)
+
+	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Dir = mountPoint
 
 	stdout, err := cmd.StdoutPipe()
@@ -166,7 +192,7 @@ func newTarReader(preallocation bool) (io.ReadCloser, error) {
 		return nil, err
 	}
 
-	return &execReader{cmd: cmd, stdout: stdout, stderr: ioutil.NopCloser(&stderr)}, nil
+	return &execReader{cmd: cmd, stdout: stdout, stderr: io.NopCloser(&stderr)}, nil
 }
 
 func getInputStream(preallocation bool) (rc io.ReadCloser) {

pkg/util/util.go

@@ -204,27 +204,22 @@ func StreamDataToFile(r io.Reader, fileName string) error {
 
 // UnArchiveTar unarchives a tar file and streams its files
 // using the specified io.Reader to the specified destination.
-func UnArchiveTar(reader io.Reader, destDir string, arg ...string) error {
+func UnArchiveTar(reader io.Reader, destDir string) error {
 	klog.V(1).Infof("begin untar to %s...\n", destDir)
-
-	var tarOptions string
-	var args = arg
-	if len(arg) > 0 {
-		tarOptions = arg[0]
-		args = arg[1:]
-	}
-	options := fmt.Sprintf("-%s%s", tarOptions, "xvC")
-	untar := exec.Command("/usr/bin/tar", "--no-same-owner", options, destDir, strings.Join(args, ""))
+	untar := exec.Command("/usr/bin/tar", "--preserve-permissions", "--no-same-owner", "-xvC", destDir)
 	untar.Stdin = reader
-	var errBuf bytes.Buffer
+	var outBuf, errBuf bytes.Buffer
+	untar.Stdout = &outBuf
 	untar.Stderr = &errBuf
+	klog.V(1).Infof("running untar cmd: %v\n", untar.Args)
 	err := untar.Start()
 	if err != nil {
 		return err
 	}
 	err = untar.Wait()
 	if err != nil {
-		klog.V(3).Infof("%s\n", errBuf.String())
+		klog.V(3).Infof("STDOUT\n%s\n", outBuf.String())
+		klog.V(3).Infof("STDERR\n%s\n", errBuf.String())
 		klog.Errorf("%s\n", err.Error())
 		return err
 	}