Fix caching to respect .dockerignore

pkg/executor/build.go

@@ -158,8 +158,10 @@ func (s *stageBuilder) populateCompositeKey(command fmt.Stringer, files []string
 		compositeKey = s.populateCopyCmdCompositeKey(command, v.From(), compositeKey)
 	}
 
+	srcCtx := s.opts.SrcContext
+
 	for _, f := range files {
-		if err := compositeKey.AddPath(f); err != nil {
+		if err := compositeKey.AddPath(f, srcCtx); err != nil {
 			return compositeKey, err
 		}
 	}

pkg/executor/build_test.go

@@ -538,7 +538,7 @@ func Test_stageBuilder_build(t *testing.T) {
 			filePath := filepath.Join(dir, file)
 			ch := NewCompositeCache("", "meow")
 
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 			hash, err := ch.Hash()
 			if err != nil {
 				t.Errorf("couldn't create hash %v", err)
@@ -570,7 +570,7 @@ func Test_stageBuilder_build(t *testing.T) {
 			filePath := filepath.Join(dir, file)
 			ch := NewCompositeCache("", "meow")
 
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 			hash, err := ch.Hash()
 			if err != nil {
 				t.Errorf("couldn't create hash %v", err)
@@ -618,7 +618,7 @@ func Test_stageBuilder_build(t *testing.T) {
 			tarContent := generateTar(t, dir, filename)
 
 			ch := NewCompositeCache("", "")
-			ch.AddPath(filepath)
+			ch.AddPath(filepath, "")
 
 			hash, err := ch.Hash()
 			if err != nil {
@@ -662,7 +662,7 @@ func Test_stageBuilder_build(t *testing.T) {
 			}
 			filePath := filepath.Join(dir, filename)
 			ch := NewCompositeCache("", "")
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 
 			hash, err := ch.Hash()
 			if err != nil {
@@ -713,15 +713,15 @@ func Test_stageBuilder_build(t *testing.T) {
 			}
 
 			ch.AddKey(fmt.Sprintf("COPY %s bar.txt", filename))
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 
 			hash2, err := ch.Hash()
 			if err != nil {
 				t.Errorf("couldn't create hash %v", err)
 			}
 			ch = NewCompositeCache("", fmt.Sprintf("COPY %s foo.txt", filename))
 			ch.AddKey(fmt.Sprintf("COPY %s bar.txt", filename))
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 
 			image := fakeImage{
 				ImageLayers: []v1.Layer{
@@ -777,22 +777,22 @@ COPY %s bar.txt
 			}
 			filePath := filepath.Join(dir, filename)
 			ch := NewCompositeCache("", fmt.Sprintf("COPY %s foo.txt", filename))
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 
 			hash1, err := ch.Hash()
 			if err != nil {
 				t.Errorf("couldn't create hash %v", err)
 			}
 			ch.AddKey(fmt.Sprintf("COPY %s bar.txt", filename))
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 
 			hash2, err := ch.Hash()
 			if err != nil {
 				t.Errorf("couldn't create hash %v", err)
 			}
 			ch = NewCompositeCache("", fmt.Sprintf("COPY %s foo.txt", filename))
 			ch.AddKey(fmt.Sprintf("COPY %s bar.txt", filename))
-			ch.AddPath(filePath)
+			ch.AddPath(filePath, "")
 
 			image := fakeImage{
 				ImageLayers: []v1.Layer{

pkg/executor/composite_cache.go

@@ -54,18 +54,28 @@ func (s *CompositeCache) Hash() (string, error) {
 	return util.SHA256(strings.NewReader(s.Key()))
 }
 
-func (s *CompositeCache) AddPath(p string) error {
+func (s *CompositeCache) AddPath(p, context string) error {
 	sha := sha256.New()
 	fi, err := os.Lstat(p)
 	if err != nil {
 		return err
 	}
+
 	if fi.Mode().IsDir() {
-		k, err := HashDir(p)
+		empty, k, err := hashDir(p, context)
 		if err != nil {
 			return err
 		}
-		s.keys = append(s.keys, k)
+
+		// Only add the hash of this directory to the key
+		// if there is any whitelisted content.
+		if !empty || !util.ExcludeFile(p, context) {
+			s.keys = append(s.keys, k)
+		}
+		return nil
+	}
+
+	if util.ExcludeFile(p, context) {
 		return nil
 	}
 	fh, err := util.CacheHasher()(p)
@@ -81,23 +91,30 @@ func (s *CompositeCache) AddPath(p string) error {
 }
 
 // HashDir returns a hash of the directory.
-func HashDir(p string) (string, error) {
+func hashDir(p, context string) (bool, string, error) {
 	sha := sha256.New()
+	empty := true
 	if err := filepath.Walk(p, func(path string, fi os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
+		exclude := util.ExcludeFile(path, context)
+		if exclude {
+			return nil
+		}
+
 		fileHash, err := util.CacheHasher()(path)
 		if err != nil {
 			return err
 		}
 		if _, err := sha.Write([]byte(fileHash)); err != nil {
 			return err
 		}
+		empty = false
 		return nil
 	}); err != nil {
-		return "", err
+		return false, "", err
 	}
 
-	return fmt.Sprintf("%x", sha.Sum(nil)), nil
+	return empty, fmt.Sprintf("%x", sha.Sum(nil)), nil
 }