fix the bug of deleting file from disk (#313)

* fix the bug of deleting file from disk

* resolve comments

* add integration test

lib/snapshot/mem_fs.go

@@ -215,7 +215,7 @@ func (fs *MemFS) UpdateFromTarReader(r *tar.Reader, untar bool) error {
 					return fmt.Errorf("untar one item %s: %s", path, err)
 				}
 			}
-			if err := fs.maybeAddToLayer(l, "", pathutils.AbsPath(hdr.Name), hdr, false); err != nil {
+			if err := fs.maybeAddToLayer(l, pathutils.AbsPath(hdr.Name), pathutils.AbsPath(hdr.Name), hdr, false); err != nil {
 				return fmt.Errorf("add hdr from tar to layer: %s", err)
 			}
 		}
@@ -229,7 +229,7 @@ func (fs *MemFS) UpdateFromTarReader(r *tar.Reader, untar bool) error {
 				return fmt.Errorf("untar one item %s: %s", path, err)
 			}
 		}
-		if err := fs.maybeAddToLayer(l, "", pathutils.AbsPath(hdr.Name), hdr, false); err != nil {
+		if err := fs.maybeAddToLayer(l, pathutils.AbsPath(hdr.Name), pathutils.AbsPath(hdr.Name), hdr, false); err != nil {
 			return fmt.Errorf("add hdr from tar to layer: %s", err)
 		}
 	}

test/python/test_build.py

@@ -5,7 +5,6 @@
 
 import image
 
-
 def test_build_simple(registry1, registry2, storage_dir):
     new_image = utils.new_image_name()
     replica_image = utils.new_image_name()
@@ -22,6 +21,16 @@ def test_build_simple(registry1, registry2, storage_dir):
     assert code == 0, err
 
 
+def test_build_remove(registry1, storage_dir):
+    new_image = utils.new_image_name()
+    context_dir = os.path.join(
+        os.getcwd(), 'testdata/build-context/remove')
+    utils.makisu_build_image(
+        new_image, context_dir, storage_dir, registry=registry1.addr)
+    code, err = utils.docker_run_image(registry1.addr, new_image)
+    assert code == 0, err
+
+
 def test_build_symlink(registry1, storage_dir):
     new_image = utils.new_image_name()
     context_dir = os.path.join(

testdata/build-context/remove/Dockerfile

@@ -0,0 +1,3 @@
+FROM centos:7
+RUN rm -vf /etc/yum.repos.d/*
+ENTRYPOINT ["/bin/bash", "-c", "echo $(ls -la /etc/yum.repos.d/)"]