Add new Path filter function to index paths based on the filter

client.go

@@ -67,7 +67,7 @@ func WithPlatform(platform string) Option {
 }
 
 // GetImageFromSource returns an image from the explicitly provided source.
-func GetImageFromSource(ctx context.Context, imgStr string, source image.Source, options ...Option) (*image.Image, error) {
+func GetImageFromSource(ctx context.Context, imgStr string, source image.Source, filter image.PathFilter, options ...Option) (*image.Image, error) {
 	log.Debugf("image: source=%+v location=%+v", source, imgStr)
 
 	var cfg config
@@ -90,7 +90,7 @@ func GetImageFromSource(ctx context.Context, imgStr string, source image.Source,
 		return nil, fmt.Errorf("unable to use %s source: %w", source, err)
 	}
 
-	err = img.Read()
+	err = img.Read(filter)
 	if err != nil {
 		return nil, fmt.Errorf("could not read image: %+v", err)
 	}
@@ -153,12 +153,12 @@ func selectImageProvider(imgStr string, source image.Source, cfg config) (image.
 
 // GetImage parses the user provided image string and provides an image object;
 // note: the source where the image should be referenced from is automatically inferred.
-func GetImage(ctx context.Context, userStr string, options ...Option) (*image.Image, error) {
+func GetImage(ctx context.Context, userStr string, filter image.PathFilter, options ...Option) (*image.Image, error) {
 	source, imgStr, err := image.DetectSource(userStr)
 	if err != nil {
 		return nil, err
 	}
-	return GetImageFromSource(ctx, imgStr, source, options...)
+	return GetImageFromSource(ctx, imgStr, source, filter, options...)
 }
 
 func SetLogger(logger logger.Logger) {

examples/basic.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+
 	"github.com/anchore/go-logger"
 	"github.com/anchore/go-logger/adapter/logrus"
 
@@ -34,7 +35,8 @@ func main() {
 	//    ./path/to.tar
 	//
 	// This will catalog the file metadata and resolve all squash trees
-	image, err := stereoscope.GetImage(ctx, os.Args[1])
+	filter := func(path string) bool { return true }
+	image, err := stereoscope.GetImage(ctx, os.Args[1], filter)
 	if err != nil {
 		panic(err)
 	}

pkg/image/image.go

@@ -173,7 +173,7 @@ func (i *Image) applyOverrideMetadata() error {
 
 // Read parses information from the underlying image tar into this struct. This includes image metadata, layer
 // metadata, layer file trees, and layer squash trees (which implies the image squash tree).
-func (i *Image) Read() error {
+func (i *Image) Read(filter PathFilter) error {
 	var layers = make([]*Layer, 0)
 	var err error
 	i.Metadata, err = readImageMetadata(i.image)
@@ -201,7 +201,7 @@ func (i *Image) Read() error {
 
 	for idx, v1Layer := range v1Layers {
 		layer := NewLayer(v1Layer)
-		err := layer.Read(&i.FileCatalog, i.Metadata, idx, i.contentCacheDir)
+		err := layer.Read(&i.FileCatalog, i.Metadata, idx, i.contentCacheDir, filter)
 		if err != nil {
 			return err
 		}

pkg/image/layer.go

@@ -24,6 +24,9 @@ import (
 
 const SingularitySquashFSLayer = "application/vnd.sylabs.sif.layer.v1.squashfs"
 
+// PathFilter decides if a path has to be included in the index
+type PathFilter = func(path string) bool
+
 // Layer represents a single layer within a container image.
 type Layer struct {
 	// layer is the raw layer metadata and content provider from the GCR lib
@@ -78,7 +81,7 @@ func (l *Layer) uncompressedTarCache(uncompressedLayersCacheDir string) (string,
 
 // Read parses information from the underlying layer tar into this struct. This includes layer metadata, the layer
 // file tree, and the layer squash tree.
-func (l *Layer) Read(catalog *FileCatalog, imgMetadata Metadata, idx int, uncompressedLayersCacheDir string) error {
+func (l *Layer) Read(catalog *FileCatalog, imgMetadata Metadata, idx int, uncompressedLayersCacheDir string, filter PathFilter) error {
 	var err error
 	l.Tree = filetree.NewFileTree()
 	l.fileCatalog = catalog
@@ -108,7 +111,7 @@ func (l *Layer) Read(catalog *FileCatalog, imgMetadata Metadata, idx int, uncomp
 			return err
 		}
 
-		l.indexedContent, err = file.NewTarIndex(tarFilePath, l.indexer(monitor))
+		l.indexedContent, err = file.NewTarIndex(tarFilePath, l.indexer(monitor, filter))
 		if err != nil {
 			return fmt.Errorf("failed to read layer=%q tar : %w", l.Metadata.Digest, err)
 		}
@@ -122,9 +125,9 @@ func (l *Layer) Read(catalog *FileCatalog, imgMetadata Metadata, idx int, uncomp
 
 		// Walk the more efficient walk if we're blessed with an io.ReaderAt.
 		if ra, ok := r.(io.ReaderAt); ok {
-			err = file.WalkSquashFS(ra, l.squashfsVisitor(monitor))
+			err = file.WalkSquashFS(ra, l.squashfsVisitor(monitor, filter))
 		} else {
-			err = file.WalkSquashFSFromReader(r, l.squashfsVisitor(monitor))
+			err = file.WalkSquashFSFromReader(r, l.squashfsVisitor(monitor, filter))
 		}
 		if err != nil {
 			return fmt.Errorf("failed to walk layer=%q: %w", l.Metadata.Digest, err)
@@ -177,7 +180,7 @@ func (l *Layer) FilesByMIMETypeFromSquash(mimeTypes ...string) ([]file.Reference
 	return refs, nil
 }
 
-func (l *Layer) indexer(monitor *progress.Manual) file.TarIndexVisitor {
+func (l *Layer) indexer(monitor *progress.Manual, filter PathFilter) file.TarIndexVisitor {
 	return func(index file.TarIndexEntry) error {
 		var err error
 		var entry = index.ToTarFileEntry()
@@ -190,6 +193,10 @@ func (l *Layer) indexer(monitor *progress.Manual) file.TarIndexVisitor {
 		}()
 		metadata := file.NewMetadata(entry.Header, entry.Sequence, contents)
 
+		if !filter(metadata.Path) {
+			return nil
+		}
+
 		// note: the tar header name is independent of surrounding structure, for example, there may be a tar header entry
 		// for /some/path/to/file.txt without any entries to constituent paths (/some, /some/path, /some/path/to ).
 		// This is ok, and the FileTree will account for this by automatically adding directories for non-existing
@@ -235,8 +242,12 @@ func (l *Layer) indexer(monitor *progress.Manual) file.TarIndexVisitor {
 	}
 }
 
-func (l *Layer) squashfsVisitor(monitor *progress.Manual) file.SquashFSVisitor {
+func (l *Layer) squashfsVisitor(monitor *progress.Manual, filter PathFilter) file.SquashFSVisitor {
 	return func(fsys fs.FS, path string, d fs.DirEntry) error {
+		if !filter(path) {
+			return nil
+		}
+
 		ff, err := fsys.Open(path)
 		if err != nil {
 			return err

pkg/image/sif/provider_test.go

@@ -36,6 +36,8 @@ func TestSingularityImageProvider_Provide(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			p := NewProviderFromPath(tt.path, file.NewTempDirGenerator(""))
 
+			filter := func(path string) bool { return true }
+
 			i, err := p.Provide(context.Background(), tt.userMetadata...)
 			t.Cleanup(func() { _ = i.Cleanup() })
 
@@ -44,7 +46,7 @@ func TestSingularityImageProvider_Provide(t *testing.T) {
 			}
 
 			if err == nil {
-				if err := i.Read(); err != nil {
+				if err := i.Read(filter); err != nil {
 					t.Fatal(err)
 				}
 			}

pkg/imagetest/image_fixtures.go

@@ -59,8 +59,9 @@ func PrepareFixtureImage(t testing.TB, source, name string) string {
 
 func GetFixtureImage(t testing.TB, source, name string) *image.Image {
 	request := PrepareFixtureImage(t, source, name)
+	filter := func(path string) bool { return true }
 
-	i, err := stereoscope.GetImage(context.TODO(), request)
+	i, err := stereoscope.GetImage(context.TODO(), request, filter)
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, i.Cleanup())
@@ -109,8 +110,9 @@ func skopeoCopyDockerArchiveToPath(t testing.TB, dockerArchivePath, destination
 
 func getFixtureImageFromTar(t testing.TB, tarPath string) *image.Image {
 	request := fmt.Sprintf("docker-archive:%s", tarPath)
+	filter := func(path string) bool { return true }
 
-	i, err := stereoscope.GetImage(context.TODO(), request)
+	i, err := stereoscope.GetImage(context.TODO(), request, filter)
 	require.NoError(t, err)
 
 	t.Cleanup(func() {

test/integration/fixture_image_simple_test.go

@@ -145,12 +145,13 @@ func BenchmarkSimpleImage_GetImage(b *testing.B) {
 			continue
 		}
 		request := imagetest.PrepareFixtureImage(b, c.source, "image-simple")
+		filter := func(path string) bool { return true }
 
 		b.Run(c.source, func(b *testing.B) {
 			var bi *image.Image
 			for i := 0; i < b.N; i++ {
 
-				bi, err = stereoscope.GetImage(context.TODO(), request)
+				bi, err = stereoscope.GetImage(context.TODO(), request, filter)
 				b.Cleanup(func() {
 					require.NoError(b, bi.Cleanup())
 				})

test/integration/mime_type_detection_test.go

@@ -2,17 +2,19 @@ package integration
 
 import (
 	"context"
+	"testing"
+
 	"github.com/anchore/stereoscope"
 	"github.com/anchore/stereoscope/pkg/imagetest"
 	"github.com/scylladb/go-set/strset"
 	"github.com/stretchr/testify/assert"
-	"testing"
 )
 
 func TestContentMIMETypeDetection(t *testing.T) {
 	request := imagetest.PrepareFixtureImage(t, "docker-archive", "image-simple")
+	filter := func(path string) bool { return true }
 
-	img, err := stereoscope.GetImage(context.TODO(), request)
+	img, err := stereoscope.GetImage(context.TODO(), request, filter)
 
 	assert.NoError(t, err)
 	t.Cleanup(stereoscope.Cleanup)

test/integration/oci_registry_source_test.go

@@ -3,9 +3,10 @@ package integration
 import (
 	"context"
 	"fmt"
-	"github.com/stretchr/testify/require"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/anchore/stereoscope"
 	"github.com/stretchr/testify/assert"
 )
@@ -31,13 +32,15 @@ func TestOciRegistrySourceMetadata(t *testing.T) {
 	imgStr := "anchore/test_images"
 	ref := fmt.Sprintf("%s@%s", imgStr, digest)
 
-	img, err := stereoscope.GetImage(context.TODO(), "registry:"+ref)
+	filter := func(path string) bool { return true }
+
+	img, err := stereoscope.GetImage(context.TODO(), "registry:"+ref, filter)
 	require.NoError(t, err)
 	t.Cleanup(func() {
 		require.NoError(t, img.Cleanup())
 	})
 
-	require.NoError(t, img.Read())
+	require.NoError(t, img.Read(filter))
 
 	assert.Len(t, img.Metadata.RepoDigests, 1)
 	assert.Equal(t, "index.docker.io/"+ref, img.Metadata.RepoDigests[0])

test/integration/platform_test.go

@@ -3,12 +3,13 @@ package integration
 import (
 	"context"
 	"fmt"
+	"strings"
+	"testing"
+
 	"github.com/anchore/stereoscope"
 	"github.com/anchore/stereoscope/pkg/image"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"strings"
-	"testing"
 )
 
 func TestPlatformSelection(t *testing.T) {
@@ -65,7 +66,8 @@ func TestPlatformSelection(t *testing.T) {
 				tt.expectedErr = require.NoError
 			}
 			platformOpt := stereoscope.WithPlatform(platform)
-			img, err := stereoscope.GetImageFromSource(context.TODO(), imageName, tt.source, platformOpt)
+			filter := func(path string) bool { return true }
+			img, err := stereoscope.GetImageFromSource(context.TODO(), imageName, tt.source, filter, platformOpt)
 			tt.expectedErr(t, err)
 			require.NotNil(t, img)