errors: drop fmtcompat.Errorf for complicated err != nil checks

These are more complicated checks than the trivial

  if err != nil {
      return fmt.Errorf("...: %w", err)
  }

but are similar and can be ported for the same reasons as the simple
case, except they needed to be hand-checked for correctness.

Signed-off-by: Aleksa Sarai <[email protected]>

cmd/umoci/init.go

@@ -24,7 +24,6 @@ import (
 
 	"github.com/apex/log"
 	"github.com/opencontainers/umoci/oci/cas/dir"
-	"github.com/opencontainers/umoci/pkg/fmtcompat"
 	"github.com/urfave/cli"
 )
 
@@ -59,7 +58,7 @@ func initLayout(ctx *cli.Context) error {
 		if err == nil {
 			err = fmt.Errorf("path already exists: %s", imagePath)
 		}
-		return fmtcompat.Errorf("image layout creation: %w", err)
+		return fmt.Errorf("image layout creation: %w", err)
 	}
 
 	if err := dir.Create(imagePath); err != nil {

cmd/umoci/insert.go

@@ -31,7 +31,6 @@ import (
 	"github.com/opencontainers/umoci/oci/casext"
 	igen "github.com/opencontainers/umoci/oci/config/generate"
 	"github.com/opencontainers/umoci/oci/layer"
-	"github.com/opencontainers/umoci/pkg/fmtcompat"
 	"github.com/urfave/cli"
 )
 
@@ -192,7 +191,7 @@ func insert(ctx *cli.Context) error {
 	// TODO: We should add a flag to allow for a new layer to be made
 	//       non-distributable.
 	if _, err := mutator.Add(context.Background(), ispec.MediaTypeImageLayer, reader, history, mutate.GzipCompressor, nil); err != nil {
-		return fmtcompat.Errorf("add diff layer: %w", err)
+		return fmt.Errorf("add diff layer: %w", err)
 	}
 
 	newDescriptorPath, err := mutator.Commit(context.Background())

cmd/umoci/raw-add-layer.go

@@ -31,7 +31,6 @@ import (
 	"github.com/opencontainers/umoci/oci/cas/dir"
 	"github.com/opencontainers/umoci/oci/casext"
 	igen "github.com/opencontainers/umoci/oci/config/generate"
-	"github.com/opencontainers/umoci/pkg/fmtcompat"
 	"github.com/urfave/cli"
 )
 
@@ -114,7 +113,7 @@ func rawAddLayer(ctx *cli.Context) error {
 		return fmt.Errorf("open new layer archive: %w", err)
 	}
 	if fi, err := newLayer.Stat(); err != nil {
-		return fmtcompat.Errorf("stat new layer archive: %w", err)
+		return fmt.Errorf("stat new layer archive: %w", err)
 	} else if fi.IsDir() {
 		return errors.New("new layer archive is a directory")
 	}
@@ -158,7 +157,7 @@ func rawAddLayer(ctx *cli.Context) error {
 	// TODO: We should add a flag to allow for a new layer to be made
 	//       non-distributable.
 	if _, err := mutator.Add(context.Background(), ispec.MediaTypeImageLayer, newLayer, history, mutate.GzipCompressor, nil); err != nil {
-		return fmtcompat.Errorf("add diff layer: %w", err)
+		return fmt.Errorf("add diff layer: %w", err)
 	}
 
 	newDescriptorPath, err := mutator.Commit(context.Background())

mutate/compress.go

@@ -9,7 +9,6 @@ import (
 	"github.com/apex/log"
 	zstd "github.com/klauspost/compress/zstd"
 	gzip "github.com/klauspost/pgzip"
-	"github.com/opencontainers/umoci/pkg/fmtcompat"
 	"github.com/opencontainers/umoci/pkg/system"
 )
 
@@ -65,14 +64,14 @@ func (gz *gzipCompressor) Compress(reader io.Reader) (io.ReadCloser, error) {
 		if err != nil {
 			log.Warnf("gzip compress: could not compress layer: %v", err)
 			// #nosec G104
-			_ = pipeWriter.CloseWithError(fmtcompat.Errorf("compressing layer: %w", err))
+			_ = pipeWriter.CloseWithError(fmt.Errorf("compressing layer: %w", err))
 			return
 		}
 		gz.bytesRead = bytesRead
 		if err := gzw.Close(); err != nil {
 			log.Warnf("gzip compress: could not close gzip writer: %v", err)
 			// #nosec G104
-			_ = pipeWriter.CloseWithError(fmtcompat.Errorf("close gzip writer: %w", err))
+			_ = pipeWriter.CloseWithError(fmt.Errorf("close gzip writer: %w", err))
 			return
 		}
 		if err := pipeWriter.Close(); err != nil {
@@ -112,14 +111,14 @@ func (zs *zstdCompressor) Compress(reader io.Reader) (io.ReadCloser, error) {
 		if err != nil {
 			log.Warnf("zstd compress: could not compress layer: %v", err)
 			// #nosec G104
-			_ = pipeWriter.CloseWithError(fmtcompat.Errorf("compressing layer: %w", err))
+			_ = pipeWriter.CloseWithError(fmt.Errorf("compressing layer: %w", err))
 			return
 		}
 		zs.bytesRead = bytesRead
 		if err := zw.Close(); err != nil {
 			log.Warnf("zstd compress: could not close gzip writer: %v", err)
 			// #nosec G104
-			_ = pipeWriter.CloseWithError(fmtcompat.Errorf("close zstd writer: %w", err))
+			_ = pipeWriter.CloseWithError(fmt.Errorf("close zstd writer: %w", err))
 			return
 		}
 		if err := pipeWriter.Close(); err != nil {

oci/cas/dir/dir.go

@@ -32,7 +32,6 @@ import (
 	imeta "github.com/opencontainers/image-spec/specs-go"
 	ispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/opencontainers/umoci/oci/cas"
-	"github.com/opencontainers/umoci/pkg/fmtcompat"
 	"github.com/opencontainers/umoci/pkg/hardening"
 	"github.com/opencontainers/umoci/pkg/system"
 	"golang.org/x/sys/unix"
@@ -111,7 +110,7 @@ func (e *dirEngine) validate() error {
 		if errors.Is(err, os.ErrNotExist) {
 			err = cas.ErrInvalid
 		}
-		return fmtcompat.Errorf("read oci-layout: %w", err)
+		return fmt.Errorf("read oci-layout: %w", err)
 	}
 
 	var ociLayout ispec.ImageLayout
@@ -122,7 +121,7 @@ func (e *dirEngine) validate() error {
 	// XXX: Currently the meaning of this field is not adequately defined by
 	//      the spec, nor is the "official" value determined by the spec.
 	if ociLayout.Version != ImageLayoutVersion {
-		return fmtcompat.Errorf("layout version is not supported: %w", cas.ErrInvalid)
+		return fmt.Errorf("layout version is not supported: %w", cas.ErrInvalid)
 	}
 
 	// Check that "blobs" and "index.json" exist in the image.
@@ -133,18 +132,18 @@ func (e *dirEngine) validate() error {
 		if errors.Is(err, os.ErrNotExist) {
 			err = cas.ErrInvalid
 		}
-		return fmtcompat.Errorf("check blobdir: %w", err)
+		return fmt.Errorf("check blobdir: %w", err)
 	} else if !fi.IsDir() {
-		return fmtcompat.Errorf("blobdir is not a directory: %w", cas.ErrInvalid)
+		return fmt.Errorf("blobdir is not a directory: %w", cas.ErrInvalid)
 	}
 
 	if fi, err := os.Stat(filepath.Join(e.path, indexFile)); err != nil {
 		if errors.Is(err, os.ErrNotExist) {
 			err = cas.ErrInvalid
 		}
-		return fmtcompat.Errorf("check index: %w", err)
+		return fmt.Errorf("check index: %w", err)
 	} else if fi.IsDir() {
-		return fmtcompat.Errorf("index is a directory: %w", cas.ErrInvalid)
+		return fmt.Errorf("index is a directory: %w", cas.ErrInvalid)
 	}
 
 	return nil
@@ -292,7 +291,7 @@ func (e *dirEngine) GetIndex(ctx context.Context) (ispec.Index, error) {
 		if errors.Is(err, os.ErrNotExist) {
 			err = cas.ErrInvalid
 		}
-		return ispec.Index{}, fmtcompat.Errorf("read index: %w", err)
+		return ispec.Index{}, fmt.Errorf("read index: %w", err)
 	}
 
 	var index ispec.Index
@@ -314,7 +313,7 @@ func (e *dirEngine) DeleteBlob(ctx context.Context, digest digest.Digest) error
 
 	err = os.Remove(filepath.Join(e.path, path))
 	if err != nil && !errors.Is(err, os.ErrNotExist) {
-		return fmtcompat.Errorf("remove blob: %w", err)
+		return fmt.Errorf("remove blob: %w", err)
 	}
 	return nil
 }
@@ -362,7 +361,7 @@ func (e *dirEngine) Clean(ctx context.Context) error {
 func (e *dirEngine) cleanPath(ctx context.Context, path string) error {
 	cfh, err := os.Open(path)
 	if err != nil && !errors.Is(err, os.ErrNotExist) {
-		return fmtcompat.Errorf("open for locking: %w", err)
+		return fmt.Errorf("open for locking: %w", err)
 	}
 	defer cfh.Close()
 

oci/config/convert/runtime.go

@@ -28,7 +28,6 @@ import (
 	ispec "github.com/opencontainers/image-spec/specs-go/v1"
 	rspec "github.com/opencontainers/runtime-spec/specs-go"
 	igen "github.com/opencontainers/umoci/oci/config/generate"
-	"github.com/opencontainers/umoci/pkg/fmtcompat"
 )
 
 // Annotations described by the OCI image-spec document (these represent fields
@@ -186,7 +185,7 @@ func MutateRuntimeSpec(spec *rspec.Spec, rootfs string, image ispec.Image) error
 		// We only log an error if were not given a rootfs, and we set execUser
 		// to the "default" (root:root).
 		if rootfs != "" {
-			return fmtcompat.Errorf("cannot parse user spec: %q: %w", ig.ConfigUser(), err)
+			return fmt.Errorf("cannot parse user spec: %q: %w", ig.ConfigUser(), err)
 		}
 		log.Warnf("could not parse user spec %q without a rootfs -- defaulting to root:root", ig.ConfigUser())
 		execUser = new(user.ExecUser)

oci/layer/generate.go

@@ -102,19 +102,19 @@ func GenerateLayer(path string, deltas []mtree.InodeDelta, opt *RepackOptions) (
 				}
 				if err := tg.AddFile(name, fullPath); err != nil {
 					log.Warnf("generate layer: could not add file %q: %s", name, err)
-					return fmtcompat.Errorf("generate layer file: %w", err)
+					return fmt.Errorf("generate layer file: %w", err)
 				}
 			case mtree.Missing:
 				if err := tg.AddWhiteout(name); err != nil {
 					log.Warnf("generate layer: could not add whiteout %q: %s", name, err)
-					return fmtcompat.Errorf("generate whiteout layer file: %w", err)
+					return fmt.Errorf("generate whiteout layer file: %w", err)
 				}
 			}
 		}
 
 		if err := tg.tw.Close(); err != nil {
 			log.Warnf("generate layer: could not close tar.Writer: %s", err)
-			return fmtcompat.Errorf("close tar writer: %w", err)
+			return fmt.Errorf("close tar writer: %w", err)
 		}
 
 		return nil

oci/layer/tar_extract.go

@@ -151,7 +151,7 @@ func (te *TarExtractor) restoreMetadata(path string, hdr *tar.Header) error {
 	err := te.fsEval.Lclearxattrs(path, ignoreXattrs)
 	if err != nil {
 		if !errors.Is(err, unix.ENOTSUP) {
-			return fmtcompat.Errorf("clear xattr metadata: %s: %w", path, err)
+			return fmt.Errorf("clear xattr metadata: %s: %w", path, err)
 		}
 		if !te.enotsupWarned {
 			log.Warnf("xattr{%s} ignoring ENOTSUP on clearxattrs", path)
@@ -210,7 +210,7 @@ func (te *TarExtractor) restoreMetadata(path string, hdr *tar.Header) error {
 				}
 				continue
 			}
-			return fmtcompat.Errorf("restore xattr metadata: %s: %w", path, err)
+			return fmt.Errorf("restore xattr metadata: %s: %w", path, err)
 		}
 	}
 
@@ -244,7 +244,7 @@ func (te *TarExtractor) applyMetadata(path string, hdr *tar.Header) error {
 func (te *TarExtractor) isDirlink(root string, path string) (bool, error) {
 	// Make sure it exists and is a symlink.
 	if _, err := te.fsEval.Readlink(path); err != nil {
-		return false, fmtcompat.Errorf("read dirlink: %w", err)
+		return false, fmt.Errorf("read dirlink: %w", err)
 	}
 
 	// Technically a string.TrimPrefix would also work...
@@ -264,7 +264,7 @@ func (te *TarExtractor) isDirlink(root string, path string) (bool, error) {
 		if errors.Is(err, unix.ELOOP) {
 			return false, nil
 		}
-		return false, fmtcompat.Errorf("sanitize old target: %w", err)
+		return false, fmt.Errorf("sanitize old target: %w", err)
 	}
 
 	targetInfo, err := te.fsEval.Lstat(targetPath)
@@ -312,7 +312,7 @@ func (te *TarExtractor) ociWhiteout(root string, dir string, file string) error
 		if securejoin.IsNotExist(err) {
 			return nil
 		}
-		return fmtcompat.Errorf("check whiteout target: %w", err)
+		return fmt.Errorf("check whiteout target: %w", err)
 	}
 
 	// Walk over the path to remove it. We remove a given path as soon as
@@ -375,7 +375,7 @@ func (te *TarExtractor) overlayFSWhiteout(dir string, file string) error {
 	// otherwise, white out the file itself.
 	p := filepath.Join(dir, strings.TrimPrefix(file, whPrefix))
 	if err := os.RemoveAll(p); err != nil && !errors.Is(err, os.ErrNotExist) {
-		return fmtcompat.Errorf("couldn't create overlayfs whiteout for %s: %w", p, err)
+		return fmt.Errorf("couldn't create overlayfs whiteout for %s: %w", p, err)
 	}
 
 	err := te.fsEval.Mknod(p, unix.S_IFCHR|0666, unix.Mkdev(0, 0))
@@ -445,7 +445,7 @@ func (te *TarExtractor) UnpackEntry(root string, hdr *tar.Header, r io.Reader) (
 		xattrs, err := te.fsEval.Llistxattr(dir)
 		if err != nil {
 			if !errors.Is(err, unix.ENOTSUP) {
-				return fmtcompat.Errorf("get dirHdr.Xattrs: %w", err)
+				return fmt.Errorf("get dirHdr.Xattrs: %w", err)
 			}
 			if !te.enotsupWarned {
 				log.Warnf("xattr{%s} ignoring ENOTSUP on llistxattr", dir)
@@ -473,7 +473,7 @@ func (te *TarExtractor) UnpackEntry(root string, hdr *tar.Header, r io.Reader) (
 			// Only overwrite the error if there wasn't one already.
 			if err := te.restoreMetadata(dir, dirHdr); err != nil {
 				if Err == nil {
-					Err = fmtcompat.Errorf("restore parent directory: %w", err)
+					Err = fmt.Errorf("restore parent directory: %w", err)
 				}
 			}
 		}()
@@ -577,7 +577,7 @@ func (te *TarExtractor) UnpackEntry(root string, hdr *tar.Header, r io.Reader) (
 		n, err := system.Copy(fh, r)
 		if int64(n) != hdr.Size {
 			if err != nil {
-				err = fmtcompat.Errorf("short write: %w", err)
+				err = fmt.Errorf("short write: %w", err)
 			} else {
 				err = io.ErrShortWrite
 			}

oci/layer/tar_generate.go

@@ -155,7 +155,7 @@ func (tg *tarGenerator) AddFile(name, path string) error {
 	linkname := ""
 	if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
 		if linkname, err = tg.fsEval.Readlink(path); err != nil {
-			return fmtcompat.Errorf("add file readlink: %w", err)
+			return fmt.Errorf("add file readlink: %w", err)
 		}
 	}
 
@@ -205,7 +205,7 @@ func (tg *tarGenerator) AddFile(name, path string) error {
 	names, err := tg.fsEval.Llistxattr(path)
 	if err != nil {
 		if !errors.Is(err, unix.EOPNOTSUPP) {
-			return fmtcompat.Errorf("get xattr list: %w", err)
+			return fmt.Errorf("get xattr list: %w", err)
 		}
 		names = []string{}
 	}
@@ -227,7 +227,7 @@ func (tg *tarGenerator) AddFile(name, path string) error {
 				// XXX: I'm not sure if we're unprivileged whether Lgetxattr can
 				//      fail with EPERM. If it can, we should ignore it (like when
 				//      we try to clear xattrs).
-				return fmtcompat.Errorf("get xattr: %s: %w", name, err)
+				return fmt.Errorf("get xattr: %s: %w", name, err)
 			}
 		}
 		// https://golang.org/issues/20698 -- We don't just error out here
@@ -276,7 +276,7 @@ func (tg *tarGenerator) AddFile(name, path string) error {
 			return fmt.Errorf("copy to layer: %w", err)
 		}
 		if n != hdr.Size {
-			return fmtcompat.Errorf("copy to layer: %w", io.ErrShortWrite)
+			return fmt.Errorf("copy to layer: %w", io.ErrShortWrite)
 		}
 	}
 

oci/layer/unpack.go

@@ -117,7 +117,7 @@ func UnpackManifest(ctx context.Context, engine cas.Engine, bundle string, manif
 		if err == nil {
 			return fmt.Errorf("config.json already exists in %s", bundle)
 		}
-		return fmtcompat.Errorf("problem accessing bundle config: %w", err)
+		return fmt.Errorf("problem accessing bundle config: %w", err)
 	}
 
 	defer func() {
@@ -136,7 +136,7 @@ func UnpackManifest(ctx context.Context, engine cas.Engine, bundle string, manif
 		if err == nil {
 			err = fmt.Errorf("%s already exists", rootfsPath)
 		}
-		return fmtcompat.Errorf("detecting rootfs: %w", err)
+		return fmt.Errorf("detecting rootfs: %w", err)
 	}
 
 	log.Infof("unpack rootfs: %s", rootfsPath)
@@ -163,7 +163,7 @@ func UnpackRootfs(ctx context.Context, engine cas.Engine, rootfsPath string, man
 	engineExt := casext.NewEngine(engine)
 
 	if err := os.Mkdir(rootfsPath, 0755); err != nil && !os.IsExist(err) {
-		return fmtcompat.Errorf("mkdir rootfs: %w", err)
+		return fmt.Errorf("mkdir rootfs: %w", err)
 	}
 
 	// In order to avoid having a broken rootfs in the case of an error, we
@@ -276,7 +276,7 @@ func UnpackRootfs(ctx context.Context, engine cas.Engine, rootfsPath string, man
 		// the whole uncompressed stream). Just blindly consume anything left
 		// in the layer.
 		if n, err := system.Copy(ioutil.Discard, layer); err != nil {
-			return fmtcompat.Errorf("discard trailing archive bits: %w", err)
+			return fmt.Errorf("discard trailing archive bits: %w", err)
 		} else if n != 0 {
 			log.Debugf("unpack manifest: layer %s: ignoring %d trailing 'junk' bytes in the tar stream -- probably from GNU tar", layerDescriptor.Digest, n)
 		}
@@ -288,7 +288,7 @@ func UnpackRootfs(ctx context.Context, engine cas.Engine, rootfsPath string, man
 		// WriteTo, which causes havoc with system.Copy. Ideally we would use
 		// layerRaw. See <https://github.com/klauspost/pgzip/issues/38>.
 		if n, err := system.Copy(ioutil.Discard, layerData); err != nil {
-			return fmtcompat.Errorf("discard trailing raw bits: %w", err)
+			return fmt.Errorf("discard trailing raw bits: %w", err)
 		} else if n != 0 {
 			log.Warnf("unpack manifest: layer %s: ignoring %d trailing 'junk' bytes in the blob stream -- this may indicate a bug in the tool which built this image", layerDescriptor.Digest, n)
 		}