cataloger: add ability to recurse with doublestar

Signed-off-by: Alfredo Deza <adeza@anchore.com>

imgbom/scope/resolvers/directory_resolver.go

@@ -5,10 +5,10 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
-	"path/filepath"
 
 	"github.com/anchore/imgbom/internal/log"
 	"github.com/anchore/stereoscope/pkg/file"
+	"github.com/bmatcuk/doublestar"
 )
 
 type DirectoryResolver struct {
@@ -51,7 +51,7 @@ func (s DirectoryResolver) FilesByGlob(patterns ...string) ([]file.Reference, er
 
 	for _, pattern := range patterns {
 		pathPattern := path.Join(s.Path, pattern)
-		matches, err := filepath.Glob(pathPattern)
+		matches, err := doublestar.Glob(pathPattern)
 		if err != nil {
 			return result, err
 		}

imgbom/scope/resolvers/directory_resolver_test.go

@@ -138,6 +138,7 @@ func TestDirectoryResolver_FilesByGlobMultiple(t *testing.T) {
 	t.Run("finds multiple matching files", func(t *testing.T) {
 		resolver := DirectoryResolver{"test-fixtures"}
 		refs, err := resolver.FilesByGlob("image-symlinks/file*")
+
 		if err != nil {
 			t.Fatalf("could not use resolver: %+v, %+v", err, refs)
 		}
@@ -149,6 +150,22 @@ func TestDirectoryResolver_FilesByGlobMultiple(t *testing.T) {
 	})
 }
 
+func TestDirectoryResolver_FilesByGlobRecursive(t *testing.T) {
+	t.Run("finds multiple matching files", func(t *testing.T) {
+		resolver := DirectoryResolver{"test-fixtures"}
+		refs, err := resolver.FilesByGlob("**/*.txt")
+
+		if err != nil {
+			t.Fatalf("could not use resolver: %+v, %+v", err, refs)
+		}
+
+		if len(refs) != 4 {
+			t.Errorf("unexpected number of refs: %d != 4", len(refs))
+		}
+
+	})
+}
+
 func TestDirectoryResolver_FilesByGlobSingle(t *testing.T) {
 	t.Run("finds multiple matching files", func(t *testing.T) {
 		resolver := DirectoryResolver{"test-fixtures"}

imgbom/scope/resolvers/test-fixtures/image-symlinks/nested/nested/file-3.txt

@@ -0,0 +1 @@
+file 3