From c75749b840dffb83e56ce48a0a75c2aec2a80397 Mon Sep 17 00:00:00 2001
From: xanonid <xanonid@gmail.com>
Date: Mon, 29 Jul 2019 20:07:31 +0200
Subject: [PATCH] Do not use leading slashes for paths in layer tarballs to be
 more compatible with docker

---
 pkg/util/tar_util.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkg/util/tar_util.go b/pkg/util/tar_util.go
index bc1cc67a0..f358f48ad 100644
--- a/pkg/util/tar_util.go
+++ b/pkg/util/tar_util.go
@@ -25,6 +25,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strings"
 	"syscall"
 
 	"github.com/docker/docker/pkg/archive"
@@ -74,7 +75,14 @@ func (t *Tar) AddFileToTar(p string) error {
 	if err != nil {
 		return err
 	}
-	hdr.Name = p
+
+	if p != "/" {
+		// Docker uses no leading / in the tarball
+		hdr.Name = strings.TrimLeft(p, "/")
+	} else {
+		// allow entry for / to preserve permission changes etc. (currently ignored anyway by Docker runtime)
+		hdr.Name = p
+	}
 
 	hardlink, linkDst := t.checkHardlink(p, i)
 	if hardlink {