directory resolver should account for the proc cwd relative to the root path (#644)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

syft/source/directory_resolver.go

@@ -34,6 +34,7 @@ type pathFilterFn func(string) bool
 // directoryResolver implements path and content access for the directory data source.
 type directoryResolver struct {
 	path              string
+	cwdRelativeToRoot string
 	cwd               string
 	fileTree          *filetree.FileTree
 	metadata          map[file.ID]FileMetadata
@@ -49,6 +50,14 @@ func newDirectoryResolver(root string, pathFilters ...pathFilterFn) (*directoryR
 		return nil, fmt.Errorf("could not create directory resolver: %w", err)
 	}
 
+	var cwdRelRoot string
+	if path.IsAbs(root) {
+		cwdRelRoot, err = filepath.Rel(cwd, root)
+		if err != nil {
+			return nil, fmt.Errorf("could not create directory resolver: %w", err)
+		}
+	}
+
 	if pathFilters == nil {
 		pathFilters = []pathFilterFn{isUnixSystemRuntimePath}
 	}
@@ -56,6 +65,7 @@ func newDirectoryResolver(root string, pathFilters ...pathFilterFn) (*directoryR
 	resolver := directoryResolver{
 		path:              root,
 		cwd:               cwd,
+		cwdRelativeToRoot: cwdRelRoot,
 		fileTree:          filetree.NewFileTree(),
 		metadata:          make(map[file.ID]FileMetadata),
 		pathFilterFns:     pathFilters,
@@ -200,7 +210,11 @@ func (r directoryResolver) requestPath(userPath string) (string, error) {
 	if filepath.IsAbs(userPath) {
 		// don't allow input to potentially hop above root path
 		userPath = path.Join(r.path, userPath)
+	} else {
+		// ensure we take into account any relative difference between the root path and the CWD for relative requests
+		userPath = path.Join(r.cwdRelativeToRoot, userPath)
 	}
+
 	var err error
 	userPath, err = filepath.Abs(userPath)
 	if err != nil {
@@ -212,7 +226,9 @@ func (r directoryResolver) requestPath(userPath string) (string, error) {
 func (r directoryResolver) responsePath(path string) string {
 	// always return references relative to the request path (not absolute path)
 	if filepath.IsAbs(path) {
-		return strings.TrimPrefix(path, r.cwd+string(filepath.Separator))
+		// we need to account for the cwd relative to the running process and the given root for the directory resolver
+		prefix := filepath.Clean(filepath.Join(r.cwd, r.cwdRelativeToRoot))
+		return strings.TrimPrefix(path, prefix+string(filepath.Separator))
 	}
 	return path
 }

syft/source/directory_resolver_test.go

@@ -10,6 +10,8 @@ import (
 	"syscall"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/scylladb/go-set/strset"
 
 	"github.com/anchore/stereoscope/pkg/file"
@@ -17,6 +19,60 @@ import (
 	"github.com/wagoodman/go-progress"
 )
 
+func TestDirectoryResolver_FilesByPath_absoluteRoot(t *testing.T) {
+	cases := []struct {
+		name         string
+		relativeRoot string
+		input        string
+		expected     []string
+	}{
+		{
+			name:         "should find a file from an absolute input",
+			relativeRoot: "./test-fixtures/",
+			input:        "/image-symlinks/file-1.txt",
+			expected: []string{
+				"image-symlinks/file-1.txt",
+			},
+		},
+		{
+			name:         "should find a file from a relative path",
+			relativeRoot: "./test-fixtures/",
+			input:        "image-symlinks/file-1.txt",
+			expected: []string{
+				"image-symlinks/file-1.txt",
+			},
+		},
+		{
+			name:         "should find a file from a relative path (root above cwd)",
+			relativeRoot: "../",
+			input:        "sbom/sbom.go",
+			expected: []string{
+				"sbom/sbom.go",
+			},
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			// note: this test is all about asserting correct functionality when the given analysis path
+			// is an absolute path
+			absRoot, err := filepath.Abs(c.relativeRoot)
+			require.NoError(t, err)
+
+			resolver, err := newDirectoryResolver(absRoot)
+			assert.NoError(t, err)
+
+			refs, err := resolver.FilesByPath(c.input)
+			require.NoError(t, err)
+			assert.Len(t, refs, len(c.expected))
+			s := strset.New()
+			for _, actual := range refs {
+				s.Add(actual.RealPath)
+			}
+			assert.ElementsMatch(t, c.expected, s.List())
+		})
+	}
+}
+
 func TestDirectoryResolver_FilesByPath(t *testing.T) {
 	cases := []struct {
 		name                 string
@@ -85,18 +141,10 @@ func TestDirectoryResolver_FilesByPath(t *testing.T) {
 			}
 
 			refs, err := resolver.FilesByPath(c.input)
-			if err != nil {
-				t.Fatalf("could not use resolver: %+v, %+v", err, refs)
-			}
-
-			if len(refs) != c.refCount {
-				t.Errorf("unexpected number of refs: %d != %d", len(refs), c.refCount)
-			}
-
+			require.NoError(t, err)
+			assert.Len(t, refs, c.refCount)
 			for _, actual := range refs {
-				if actual.RealPath != c.expected {
-					t.Errorf("bad resolve path: '%s'!='%s'", actual.RealPath, c.expected)
-				}
+				assert.Equal(t, c.expected, actual.RealPath)
 			}
 		})
 	}