Merge pull request moby#5170 from jsternberg/pkg-errors-remove-cause

errors: remove usage of errors.Cause

Author: tonistiigi

cache/util/fsutil.go

@@ -131,16 +131,24 @@ func StatFile(ctx context.Context, mount snapshot.Mountable, path string) (*fsty
 			// The filename here is internal to the mount, so we can restore
 			// the request base path for error reporting.
 			// See os.DirFS.Open for details.
-			err1 := err
-			if err := errors.Cause(err); err != nil {
-				err1 = err
-			}
-			if pe, ok := err1.(*os.PathError); ok {
-				pe.Path = path
-			}
+			replaceErrorPath(err, path)
 			return errors.WithStack(err)
 		}
 		return nil
 	})
 	return st, err
 }
+
+// replaceErrorPath will override the path in an os.PathError in the error chain.
+// This works with the fsutil library, but it isn't necessarily the correct
+// way to do this because the error message of wrapped errors doesn't necessarily
+// update or change when a wrapped error is changed.
+//
+// Still, this method of updating the path works with the way this specific
+// library returns errors.
+func replaceErrorPath(err error, path string) {
+	var pe *os.PathError
+	if errors.As(err, &pe) {
+		pe.Path = path
+	}
+}

cache/util/fsutil_test.go

@@ -0,0 +1,31 @@
+package util
+
+import (
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/tonistiigi/fsutil"
+)
+
+// TestSetErrorPath ensures that modifying the os.PathError from fsutil.Stat
+// modifies the error message appropriately.
+//
+// This method of modifying the path error is an implementation
+// detail of how the error is returned. It isn't necessarily the
+// case that this will always work if the underlying library changes.
+func TestSetErrorPath(t *testing.T) {
+	// Temporary directory to reduce the chance of using stat on a real file.
+	dir := t.TempDir()
+
+	// Random path that shouldn't exist.
+	fpath := path.Join(dir, "a/b/c")
+	_, err := fsutil.Stat(fpath)
+	require.Error(t, err)
+
+	require.ErrorContains(t, err, "a/b/c")
+	// Set the path in the error to a new path.
+	replaceErrorPath(err, "/my/new/path")
+	require.NotContains(t, err.Error(), "a/b/c")
+	require.Contains(t, err.Error(), "/my/new/path")
+}

util/resolver/retryhandler/retry.go

@@ -64,11 +64,7 @@ func retryError(err error) bool {
 		return true
 	}
 	// catches TLS timeout or other network-related temporary errors
-	if ne, ok := errors.Cause(err).(net.Error); ok && ne.Temporary() { //nolint:staticcheck // ignoring "SA1019: Temporary is deprecated", continue to propagate net.Error through the "temporary" status
-		return true
-	}
-	// https://github.com/containerd/containerd/pull/4724
-	if errors.Cause(err).Error() == "no response" {
+	if ne := net.Error(nil); errors.As(err, &ne) && ne.Temporary() { //nolint:staticcheck // ignoring "SA1019: Temporary is deprecated", continue to propagate net.Error through the "temporary" status
 		return true
 	}
 

util/system/path_test.go

@@ -3,7 +3,6 @@ package system
 import (
 	"testing"
 
-	"github.com/pkg/errors"
 	"github.com/stretchr/testify/require"
 )
 
@@ -77,7 +76,7 @@ func TestNormalizeWorkdir(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			result, err := NormalizeWorkdir(tc.currentWorkdir, tc.newWorkDir, "linux")
 			if tc.err != "" {
-				require.EqualError(t, errors.Cause(err), tc.err)
+				require.ErrorContains(t, err, tc.err)
 			} else {
 				require.NoError(t, err)
 			}
@@ -300,7 +299,7 @@ func TestNormalizeWorkdirWindows(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			result, err := NormalizeWorkdir(tc.currentWorkdir, tc.newWorkDir, "windows")
 			if tc.err != "" {
-				require.EqualError(t, errors.Cause(err), tc.err)
+				require.ErrorContains(t, err, tc.err)
 			} else {
 				require.NoError(t, err)
 			}
@@ -365,7 +364,7 @@ func TestNormalizeWorkdirUnix(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			result, err := NormalizeWorkdir(tc.currentWorkdir, tc.newWorkDir, "linux")
 			if tc.err != "" {
-				require.EqualError(t, errors.Cause(err), tc.err)
+				require.ErrorContains(t, err, tc.err)
 			} else {
 				require.NoError(t, err)
 			}