Merge pull request #992 from estesp/errrbody-likes-errrrors

Use error interfaces for content/metadata

content/content.go

@@ -7,26 +7,9 @@ import (
 	"time"
 
 	"github.com/opencontainers/go-digest"
-	"github.com/pkg/errors"
 )
 
 var (
-	// ErrNotFound is returned when an item is not found.
-	//
-	// Use IsNotFound(err) to detect this condition.
-	ErrNotFound = errors.New("content: not found")
-
-	// ErrExists is returned when something exists when it may not be expected.
-	//
-	// Use IsExists(err) to detect this condition.
-	ErrExists = errors.New("content: exists")
-
-	// ErrLocked is returned when content is actively being uploaded, this
-	// indicates that another process is attempting to upload the same content.
-	//
-	// Use IsLocked(err) to detect this condition.
-	ErrLocked = errors.New("content: locked")
-
 	bufPool = sync.Pool{
 		New: func() interface{} {
 			return make([]byte, 1<<20)
@@ -106,15 +89,3 @@ type Store interface {
 	Ingester
 	Provider
 }
-
-func IsNotFound(err error) bool {
-	return errors.Cause(err) == ErrNotFound
-}
-
-func IsExists(err error) bool {
-	return errors.Cause(err) == ErrExists
-}
-
-func IsLocked(err error) bool {
-	return errors.Cause(err) == ErrLocked
-}

content/errors.go

@@ -0,0 +1,120 @@
+package content
+
+type contentExistsErr struct {
+	desc string
+}
+
+type contentNotFoundErr struct {
+	desc string
+}
+
+type contentLockedErr struct {
+	desc string
+}
+
+// ErrExists is returned when something exists when it may not be expected.
+func ErrExists(msg string) error {
+	if msg == "" {
+		msg = "content: exists"
+	}
+	return contentExistsErr{
+		desc: msg,
+	}
+}
+
+// ErrNotFound is returned when an item is not found.
+func ErrNotFound(msg string) error {
+	if msg == "" {
+		msg = "content: not found"
+	}
+	return contentNotFoundErr{
+		desc: msg,
+	}
+}
+
+// ErrLocked is returned when content is actively being uploaded, this
+// indicates that another process is attempting to upload the same content.
+func ErrLocked(msg string) error {
+	if msg == "" {
+		msg = "content: locked"
+	}
+	return contentLockedErr{
+		desc: msg,
+	}
+}
+
+func (c contentExistsErr) Error() string {
+	return c.desc
+}
+func (c contentNotFoundErr) Error() string {
+	return c.desc
+}
+func (c contentLockedErr) Error() string {
+	return c.desc
+}
+
+func (c contentExistsErr) Exists() bool {
+	return true
+}
+
+func (c contentNotFoundErr) NotFound() bool {
+	return true
+}
+
+func (c contentLockedErr) Locked() bool {
+	return true
+}
+
+// IsNotFound returns true if the error is due to a not found content item
+func IsNotFound(err error) bool {
+	if err, ok := err.(interface {
+		NotFound() bool
+	}); ok {
+		return err.NotFound()
+	}
+
+	causal, ok := err.(interface {
+		Cause() error
+	})
+	if !ok {
+		return false
+	}
+
+	return IsNotFound(causal.Cause())
+}
+
+// IsExists returns true if the error is due to an already existing content item
+func IsExists(err error) bool {
+	if err, ok := err.(interface {
+		Exists() bool
+	}); ok {
+		return err.Exists()
+	}
+
+	causal, ok := err.(interface {
+		Cause() error
+	})
+	if !ok {
+		return false
+	}
+
+	return IsExists(causal.Cause())
+}
+
+// IsLocked returns true if the error is due to a currently locked content item
+func IsLocked(err error) bool {
+	if err, ok := err.(interface {
+		Locked() bool
+	}); ok {
+		return err.Locked()
+	}
+
+	causal, ok := err.(interface {
+		Cause() error
+	})
+	if !ok {
+		return false
+	}
+
+	return IsLocked(causal.Cause())
+}

content/locks.go

@@ -1,9 +1,8 @@
 package content
 
 import (
+	"fmt"
 	"sync"
-
-	"github.com/pkg/errors"
 )
 
 // Handles locking references
@@ -20,7 +19,7 @@ func tryLock(ref string) error {
 	defer locksMu.Unlock()
 
 	if _, ok := locks[ref]; ok {
-		return errors.Wrapf(ErrLocked, "key %s is locked", ref)
+		return ErrLocked(fmt.Sprintf("key %s is locked", ref))
 	}
 
 	locks[ref] = struct{}{}

content/store.go

@@ -40,7 +40,7 @@ func (s *store) Info(ctx context.Context, dgst digest.Digest) (Info, error) {
 	fi, err := os.Stat(p)
 	if err != nil {
 		if os.IsNotExist(err) {
-			err = ErrNotFound
+			err = ErrNotFound("")
 		}
 
 		return Info{}, err
@@ -62,7 +62,7 @@ func (s *store) Reader(ctx context.Context, dgst digest.Digest) (io.ReadCloser,
 	fp, err := os.Open(s.blobPath(dgst))
 	if err != nil {
 		if os.IsNotExist(err) {
-			err = ErrNotFound
+			err = ErrNotFound("")
 		}
 		return nil, err
 	}
@@ -85,7 +85,7 @@ func (cs *store) Delete(ctx context.Context, dgst digest.Digest) error {
 			return err
 		}
 
-		return ErrNotFound
+		return ErrNotFound("")
 	}
 
 	return nil
@@ -329,7 +329,7 @@ func (s *store) Abort(ctx context.Context, ref string) error {
 	root := s.ingestRoot(ref)
 	if err := os.RemoveAll(root); err != nil {
 		if os.IsNotExist(err) {
-			return ErrNotFound
+			return ErrNotFound("")
 		}
 
 		return err

content/writer.go

@@ -99,7 +99,7 @@ func (w *writer) Commit(size int64, expected digest.Digest) error {
 	if err := os.Rename(ingest, target); err != nil {
 		if os.IsExist(err) {
 			// collision with the target file!
-			return ErrExists
+			return ErrExists("")
 		}
 		return err
 	}

metadata/containers.go

@@ -28,7 +28,7 @@ func (s *containerStore) Get(ctx context.Context, id string) (containers.Contain
 
 	bkt := getContainerBucket(s.tx, namespace, id)
 	if bkt == nil {
-		return containers.Container{}, errors.Wrap(ErrNotFound, "bucket does not exist")
+		return containers.Container{}, ErrNotFound("bucket does not exist")
 	}
 
 	container := containers.Container{ID: id}
@@ -85,7 +85,7 @@ func (s *containerStore) Create(ctx context.Context, container containers.Contai
 	cbkt, err := bkt.CreateBucket([]byte(container.ID))
 	if err != nil {
 		if err == bolt.ErrBucketExists {
-			err = errors.Wrap(ErrExists, "content for id already exists")
+			err = ErrExists("content for id already exists")
 		}
 		return containers.Container{}, err
 	}
@@ -107,12 +107,12 @@ func (s *containerStore) Update(ctx context.Context, container containers.Contai
 
 	bkt := getContainersBucket(s.tx, namespace)
 	if bkt == nil {
-		return containers.Container{}, errors.Wrap(ErrNotFound, "no containers")
+		return containers.Container{}, ErrNotFound("no containers")
 	}
 
 	cbkt := bkt.Bucket([]byte(container.ID))
 	if cbkt == nil {
-		return containers.Container{}, errors.Wrap(ErrNotFound, "no content for id")
+		return containers.Container{}, ErrNotFound("no content for id")
 	}
 
 	container.UpdatedAt = time.Now()
@@ -131,11 +131,11 @@ func (s *containerStore) Delete(ctx context.Context, id string) error {
 
 	bkt := getContainersBucket(s.tx, namespace)
 	if bkt == nil {
-		return errors.Wrap(ErrNotFound, "no containers")
+		return ErrNotFound("no containers")
 	}
 
 	if err := bkt.DeleteBucket([]byte(id)); err == bolt.ErrBucketNotFound {
-		return errors.Wrap(ErrNotFound, "no content for id")
+		return ErrNotFound("no content for id")
 	}
 	return err
 }

metadata/errors.go

@@ -1,22 +1,117 @@
 package metadata
 
-import "github.com/pkg/errors"
+type metadataExistsErr struct {
+	desc string
+}
+type metadataNotFoundErr struct {
+	desc string
+}
+type metadataNotEmptyErr struct {
+	desc string
+}
 
-var (
-	ErrExists   = errors.New("metadata: exists")
-	ErrNotFound = errors.New("metadata: not found")
-	ErrNotEmpty = errors.New("metadata: namespace not empty")
-)
+// ErrExists is returned when an item already exists in metadata
+func ErrExists(msg string) error {
+	if msg == "" {
+		msg = "metadata: exists"
+	}
+	return metadataExistsErr{
+		desc: msg,
+	}
+}
 
-// IsNotFound returns true if the error is due to a missing image.
+// ErrNotFound is returned when an item cannot be found in metadata
+func ErrNotFound(msg string) error {
+	if msg == "" {
+		msg = "metadata: not found"
+	}
+	return metadataNotFoundErr{
+		desc: msg,
+	}
+}
+
+// ErrNotEmpty is returned when a metadata item can't be deleted because it is not empty
+func ErrNotEmpty(msg string) error {
+	if msg == "" {
+		msg = "metadata: namespace not empty"
+	}
+	return metadataNotEmptyErr{
+		desc: msg,
+	}
+}
+
+func (m metadataExistsErr) Error() string {
+	return m.desc
+}
+func (m metadataNotFoundErr) Error() string {
+	return m.desc
+}
+func (m metadataNotEmptyErr) Error() string {
+	return m.desc
+}
+
+func (m metadataExistsErr) Exists() bool {
+	return true
+}
+
+func (m metadataNotFoundErr) NotFound() bool {
+	return true
+}
+
+func (m metadataNotEmptyErr) NotEmpty() bool {
+	return true
+}
+
+// IsNotFound returns true if the error is due to a missing metadata item
 func IsNotFound(err error) bool {
-	return errors.Cause(err) == ErrNotFound
+	if err, ok := err.(interface {
+		NotFound() bool
+	}); ok {
+		return err.NotFound()
 	}
 
+	causal, ok := err.(interface {
+		Cause() error
+	})
+	if !ok {
+		return false
+	}
+
+	return IsNotFound(causal.Cause())
+}
+
+// IsExists returns true if the error is due to an already existing metadata item
 func IsExists(err error) bool {
-	return errors.Cause(err) == ErrExists
+	if err, ok := err.(interface {
+		Exists() bool
+	}); ok {
+		return err.Exists()
 	}
 
-func IsNotEmpty(err error) bool {
-	return errors.Cause(err) == ErrNotEmpty
+	causal, ok := err.(interface {
+		Cause() error
+	})
+	if !ok {
+		return false
+	}
+
+	return IsExists(causal.Cause())
+}
+
+// IsNotEmpty returns true if the error is due to delete request of a non-empty metadata item
+func IsNotEmpty(err error) bool {
+	if err, ok := err.(interface {
+		NotEmpty() bool
+	}); ok {
+		return err.NotEmpty()
+	}
+
+	causal, ok := err.(interface {
+		Cause() error
+	})
+	if !ok {
+		return false
+	}
+
+	return IsNotEmpty(causal.Cause())
 }

metadata/images.go

@@ -30,12 +30,12 @@ func (s *imageStore) Get(ctx context.Context, name string) (images.Image, error)
 
 	bkt := getImagesBucket(s.tx, namespace)
 	if bkt == nil {
-		return images.Image{}, ErrNotFound
+		return images.Image{}, ErrNotFound("")
 	}
 
 	ibkt := bkt.Bucket([]byte(name))
 	if ibkt == nil {
-		return images.Image{}, ErrNotFound
+		return images.Image{}, ErrNotFound("")
 	}
 
 	image.Name = name
@@ -124,7 +124,7 @@ func (s *imageStore) Delete(ctx context.Context, name string) error {
 	return withImagesBucket(s.tx, namespace, func(bkt *bolt.Bucket) error {
 		err := bkt.DeleteBucket([]byte(name))
 		if err == bolt.ErrBucketNotFound {
-			return ErrNotFound
+			return ErrNotFound("")
 		}
 		return err
 	})

metadata/namespaces.go

@@ -25,7 +25,7 @@ func (s *namespaceStore) Create(ctx context.Context, namespace string, labels ma
 	bkt, err := topbkt.CreateBucket([]byte(namespace))
 	if err != nil {
 		if err == bolt.ErrBucketExists {
-			return ErrExists
+			return ErrExists("")
 		}
 
 		return err
@@ -100,12 +100,12 @@ func (s *namespaceStore) Delete(ctx context.Context, namespace string) error {
 	if empty, err := s.namespaceEmpty(ctx, namespace); err != nil {
 		return err
 	} else if !empty {
-		return ErrNotEmpty
+		return ErrNotEmpty("")
 	}
 
 	if err := bkt.DeleteBucket([]byte(namespace)); err != nil {
 		if err == bolt.ErrBucketNotFound {
-			return ErrNotFound
+			return ErrNotFound("")
 		}
 
 		return err

remotes/docker/pusher.go

@@ -31,7 +31,7 @@ func (p dockerPusher) Push(ctx context.Context, desc ocispec.Descriptor) (conten
 	status, err := p.tracker.GetStatus(ref)
 	if err == nil {
 		if status.Offset == status.Total {
-			return nil, content.ErrExists
+			return nil, content.ErrExists("")
 		}
 		// TODO: Handle incomplete status
 	} else if !content.IsNotFound(err) {
@@ -72,7 +72,7 @@ func (p dockerPusher) Push(ctx context.Context, desc ocispec.Descriptor) (conten
 					// TODO: Set updated time?
 				},
 			})
-			return nil, content.ErrExists
+			return nil, content.ErrExists("")
 		}
 		if resp.StatusCode != http.StatusNotFound {
 			// TODO: log error

remotes/docker/status.go

@@ -34,7 +34,7 @@ func (t *memoryStatusTracker) GetStatus(ref string) (Status, error) {
 	defer t.m.Unlock()
 	status, ok := t.statuses[ref]
 	if !ok {
-		return Status{}, content.ErrNotFound
+		return Status{}, content.ErrNotFound("")
 	}
 	return status, nil
 }

services/content/helpers.go

@@ -10,13 +10,12 @@ import (
 func rewriteGRPCError(err error) error {
 	switch grpc.Code(errors.Cause(err)) {
 	case codes.AlreadyExists:
-		return content.ErrExists
+		return content.ErrExists(grpc.ErrorDesc(err))
 	case codes.NotFound:
-		return content.ErrNotFound
+		return content.ErrNotFound(grpc.ErrorDesc(err))
 	case codes.Unavailable:
-		return content.ErrLocked
+		return content.ErrLocked(grpc.ErrorDesc(err))
 	}
-
 	return err
 }
 

services/images/helpers.go

@@ -69,9 +69,9 @@ func rewriteGRPCError(err error) error {
 
 	switch grpc.Code(errors.Cause(err)) {
 	case codes.AlreadyExists:
-		return metadata.ErrExists
+		return metadata.ErrExists(grpc.ErrorDesc(err))
 	case codes.NotFound:
-		return metadata.ErrNotFound
+		return metadata.ErrNotFound(grpc.ErrorDesc(err))
 	}
 
 	return err

services/namespaces/helpers.go

@@ -27,9 +27,9 @@ func rewriteGRPCError(err error) error {
 
 	switch grpc.Code(errors.Cause(err)) {
 	case codes.AlreadyExists:
-		return metadata.ErrExists
+		return metadata.ErrExists(grpc.ErrorDesc(err))
 	case codes.NotFound:
-		return metadata.ErrNotFound
+		return metadata.ErrNotFound(grpc.ErrorDesc(err))
 	}
 
 	return err