Only add whiteout files once

integration/dockerfiles/Dockerfile_test_mv_add

@@ -1,3 +1,4 @@
 FROM busybox@sha256:1bd6df27274fef1dd36eb529d0f4c8033f61c675d6b04213dd913f902f7cafb5
 ADD context/tars /tmp/tars
 RUN mv /tmp/tars /foo
+RUN echo "hi"

pkg/snapshot/layered_map.go

@@ -22,8 +22,9 @@ import (
 )
 
 type LayeredMap struct {
-	layers []map[string]string
-	hasher func(string) (string, error)
+	layers    []map[string]string
+	whiteouts []map[string]string
+	hasher    func(string) (string, error)
 }
 
 func NewLayeredMap(h func(string) (string, error)) *LayeredMap {
@@ -35,6 +36,7 @@ func NewLayeredMap(h func(string) (string, error)) *LayeredMap {
 }
 
 func (l *LayeredMap) Snapshot() {
+	l.whiteouts = append(l.whiteouts, map[string]string{})
 	l.layers = append(l.layers, map[string]string{})
 }
 
@@ -62,6 +64,24 @@ func (l *LayeredMap) Get(s string) (string, bool) {
 	return "", false
 }
 
+func (l *LayeredMap) GetWhiteout(s string) (string, bool) {
+	for i := len(l.whiteouts) - 1; i >= 0; i-- {
+		if v, ok := l.whiteouts[i][s]; ok {
+			return v, ok
+		}
+	}
+	return "", false
+}
+
+func (l *LayeredMap) MaybeAddWhiteout(s string) (bool, error) {
+	whiteout, ok := l.GetWhiteout(s)
+	if ok && whiteout == s {
+		return false, nil
+	}
+	l.whiteouts[len(l.whiteouts)-1][s] = s
+	return true, nil
+}
+
 func (l *LayeredMap) MaybeAdd(s string) (bool, error) {
 	oldV, ok := l.Get(s)
 	newV, err := l.hasher(s)

pkg/snapshot/snapshot.go

@@ -19,12 +19,13 @@ package snapshot
 import (
 	"archive/tar"
 	"bytes"
-	"github.com/GoogleContainerTools/kaniko/pkg/util"
-	"github.com/sirupsen/logrus"
 	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+
+	"github.com/GoogleContainerTools/kaniko/pkg/util"
+	"github.com/sirupsen/logrus"
 )
 
 // Snapshotter holds the root directory from which to take snapshots, and a list of snapshots taken
@@ -103,11 +104,11 @@ func (s *Snapshotter) snapshotFiles(f io.Writer, files []string) (bool, error) {
 			return false, err
 		}
 		// Only add to the tar if we add it to the layeredmap.
-		maybeAdd, err := s.l.MaybeAdd(file)
+		addFile, err := s.l.MaybeAdd(file)
 		if err != nil {
 			return false, err
 		}
-		if maybeAdd {
+		if addFile {
 			filesAdded = true
 			if err := util.AddToTar(file, info, s.hardlinks, w); err != nil {
 				return false, err
@@ -141,10 +142,16 @@ func (s *Snapshotter) snapShotFS(f io.Writer) (bool, error) {
 		// Only add the whiteout if the directory for the file still exists.
 		dir := filepath.Dir(path)
 		if _, ok := memFs[dir]; ok {
-			logrus.Infof("Adding whiteout for %s", path)
-			filesAdded = true
-			if err := util.Whiteout(path, w); err != nil {
-				return false, err
+			addWhiteout, err := s.l.MaybeAddWhiteout(path)
+			if err != nil {
+				return false, nil
+			}
+			if addWhiteout {
+				logrus.Infof("Adding whiteout for %s", path)
+				filesAdded = true
+				if err := util.Whiteout(path, w); err != nil {
+					return false, err
+				}
 			}
 		}
 	}