README: remove mention of license

It was out of date; there is also a license file that's up to date.

Makefile

@@ -5,7 +5,7 @@ VSN ?= $(shell git describe --dirty)
 VSNHASH ?= $(shell git rev-parse --verify HEAD)
 LDFLAGS ?= -ldflags "-X main.Version=$(VSN) -X main.VersionHash=$(VSNHASH)"
 
-undocker: ## builds binary for the current architecture
+undocker: $(GODEPS) ## builds binary for the current architecture
 	go build $(LDFLAGS) -o $@
 
 .PHONY: test
@@ -16,7 +16,7 @@ lint:
 	go vet ./...
 	staticcheck -f stylish ./...
 	shellcheck $(SCRIPTS)
-	shfmt $(SCRIPTS)
+	shfmt -w -i 4 $(SCRIPTS)
 	git diff --exit-code
 
 .INTERMEDIATE: coverage.out
@@ -30,7 +30,9 @@ coverage.html: coverage.out
 clean:
 	rm -f undocker coverage.html
 
-TEST_IMAGES = busybox-glibc_65ad0d468eb1
+TEST_IMAGES = \
+			  busybox-glibc_65ad0d468eb1 \
+			  docker_v27.1.2_save
 
 .PHONY: test-integration
 test-integration: $(foreach IMG,$(TEST_IMAGES),test-integration-$(IMG))

README.md

@@ -108,12 +108,7 @@ rejected.
 Communication
 -------------
 
-Feel free to ping me [directly][motiejus-comms].
-
-LICENSE
--------
-
-MIT
+Ping me [directly][motiejus-comms].
 
 [1]: https://www.freedesktop.org/software/systemd/man/systemd.exec.html
 [2]: https://fly.io/blog/docker-without-docker/

rootfs/rootfs.go

@@ -40,8 +40,8 @@ func Flatten(rd io.ReadSeeker, w io.Writer) (_err error) {
 	var closer func() error
 	var err error
 
-	// layerOffsets maps a layer name (a9b123c0daa/layer.tar) to it's offset
-	layerOffsets := map[string]int64{}
+	// fileOffsets maps a file name (a9b123c0daa/layer.tar) to it's offset
+	fileOffsets := map[string]int64{}
 
 	// manifest is the docker manifest in the image
 	var manifest dockerManifestJSON
@@ -58,31 +58,29 @@ func Flatten(rd io.ReadSeeker, w io.Writer) (_err error) {
 		if hdr.Typeflag != tar.TypeReg {
 			continue
 		}
-		switch {
-		case filepath.Clean(hdr.Name) == _manifestJSON:
+		here, err := rd.Seek(0, io.SeekCurrent)
+		if err != nil {
+			return err
+		}
+		fileOffsets[strings.TrimPrefix(hdr.Name, "./")] = here
+		if filepath.Clean(hdr.Name) == _manifestJSON {
 			dec := json.NewDecoder(tr)
 			if err := dec.Decode(&manifest); err != nil {
 				return fmt.Errorf("decode %s: %w", _manifestJSON, err)
 			}
-		case strings.HasSuffix(hdr.Name, _tarSuffix):
-			here, err := rd.Seek(0, io.SeekCurrent)
-			if err != nil {
-				return err
-			}
-			layerOffsets[strings.TrimPrefix(hdr.Name, "./")] = here
 		}
 	}
 
-	if err := validateManifest(layerOffsets, manifest); err != nil {
+	if err := validateManifest(fileOffsets, manifest); err != nil {
 		return err
 	}
 
 	// enumerate layers the way they would be laid down in the image
-	layers := make([]nameOffset, len(layerOffsets))
+	layers := make([]nameOffset, len(manifest[0].Layers))
 	for i, name := range manifest[0].Layers {
 		layers[i] = nameOffset{
 			name:   name,
-			offset: layerOffsets[strings.TrimPrefix(name, "./")],
+			offset: fileOffsets[strings.TrimPrefix(name, "./")],
 		}
 	}
 
@@ -232,7 +230,7 @@ func whiteoutDirs(whreaddir map[string]int, nlayers int) []*tree {
 
 // validateManifest
 func validateManifest(
-	layerOffsets map[string]int64,
+	fileOffsets map[string]int64,
 	manifest dockerManifestJSON,
 ) error {
 	if len(manifest) == 0 {
@@ -240,7 +238,7 @@ func validateManifest(
 	}
 
 	for _, layer := range manifest[0].Layers {
-		if _, ok := layerOffsets[layer]; !ok {
+		if _, ok := fileOffsets[layer]; !ok {
 			return fmt.Errorf("%s defined in manifest, missing in tarball", layer)
 		}
 	}

t/docker_v27.1.2_save.txt

@@ -0,0 +1 @@
+-rw-r--r-- 0/0              39 2024-09-10 10:49 Dockerfile