Round 2

Make Errors a []Error

Signed-off-by: Doug Davis <dug@us.ibm.com>

registry/api/errcode/errors.go

@@ -55,8 +55,8 @@ var errorDescriptors = []ErrorDescriptor{
 }
 
 // LoadErrors will register a new set of Errors into the system
-func LoadErrors(errs *[]ErrorDescriptor) {
+func LoadErrors(errs []ErrorDescriptor) {
-	for _, descriptor := range *errs {
+	for _, descriptor := range errs {
 		if _, ok := idToDescriptors[descriptor.Value]; ok {
 			panic(fmt.Sprintf("ErrorValue %s is already registered", descriptor.Value))
 		}
@@ -123,28 +123,28 @@ func (ec *ErrorCode) UnmarshalText(text []byte) error {
 
 // Error provides a wrapper around ErrorCode with extra Details provided.
 type Error struct {
-	Code    ErrorCode   `json:"code"`
+	Code   ErrorCode   `json:"code"`
-	Message string      `json:"message,omitempty"`
+	Detail interface{} `json:"detail,omitempty"`
-	Detail  interface{} `json:"detail,omitempty"`
 }
 
 // Error returns a human readable representation of the error.
 func (e Error) Error() string {
 	return fmt.Sprintf("%s: %s",
 		strings.ToLower(strings.Replace(e.Code.String(), "_", " ", -1)),
-		e.Message)
+		e.Code.Message())
+}
+
+// Message returned the human-readable error message for this Error
+func (e Error) Message() string {
+	return e.Code.Message()
 }
 
 // Errors provides the envelope for multiple errors and a few sugar methods
 // for use within the application.
-type Errors struct {
+type Errors []Error
-	Errors []Error `json:"errors,omitempty"`
-}
 
-// Push pushes an error on to the error stack, with the optional detail
+// NewError creates a new Error struct based on the passed-in info
-// argument. It is a programming error (ie panic) to push more than one
+func NewError(code ErrorCode, details ...interface{}) Error {
-// detail at a time.
-func (errs *Errors) Push(code ErrorCode, details ...interface{}) {
 	if len(details) > 1 {
 		panic("please specify zero or one detail items for this error")
 	}
@@ -158,49 +158,33 @@ func (errs *Errors) Push(code ErrorCode, details ...interface{}) {
 		detail = err.Error()
 	}
 
-	errs.PushErr(Error{
+	return Error{
-		Code:    code,
+		Code:   code,
-		Message: code.Message(),
+		Detail: detail,
-		Detail:  detail,
-	})
-}
-
-// PushErr pushes an error interface onto the error stack.
-func (errs *Errors) PushErr(err error) {
-	switch err.(type) {
-	case Error:
-		errs.Errors = append(errs.Errors, err.(Error))
-	default:
-		errs.Errors = append(errs.Errors, Error{Message: err.Error()})
 	}
 }
 
-func (errs *Errors) Error() string {
+func (errs Errors) Error() string {
-	switch errs.Len() {
+	switch len(errs) {
 	case 0:
 		return "<nil>"
 	case 1:
-		return errs.Errors[0].Error()
+		return errs[0].Error()
 	default:
 		msg := "errors:\n"
-		for _, err := range errs.Errors {
+		for _, err := range errs {
 			msg += err.Error() + "\n"
 		}
 		return msg
 	}
 }
 
-// Clear clears the errors.
-func (errs *Errors) Clear() {
-	errs.Errors = nil
-}
-
 // Len returns the current number of errors.
-func (errs *Errors) Len() int {
+func (errs Errors) Len() int {
-	return len(errs.Errors)
+	return len(errs)
 }
 
 // init loads the default errors that are part of the errcode package
 func init() {
-	LoadErrors(&errorDescriptors)
+	LoadErrors(errorDescriptors)
 }

registry/api/v2/errors.go

@@ -188,5 +188,5 @@ var errorDescriptors = []errcode.ErrorDescriptor{
 
 // init registers our errors with the errcode system
 func init() {
-	errcode.LoadErrors(&errorDescriptors)
+	errcode.LoadErrors(errorDescriptors)
 }

registry/client/blob_writer_test.go

@@ -86,15 +86,12 @@ func TestUploadReadFrom(t *testing.T) {
 			Response: testutil.Response{
 				StatusCode: http.StatusBadRequest,
 				Body: []byte(`
-				{
+					[
-					"errors": [
 						{
 							"code": "BLOB_UPLOAD_INVALID",
-							"message": "invalid upload identifier",
 							"detail": "more detail"
 						}
-					]
+					] `),
-				}`),
 			},
 		},
 		// Test 400 invalid json
@@ -162,17 +159,17 @@ func TestUploadReadFrom(t *testing.T) {
 	if err == nil {
 		t.Fatalf("Expected error when not found")
 	}
-	if uploadErr, ok := err.(*errcode.Errors); !ok {
+	if uploadErr, ok := err.(errcode.Errors); !ok {
 		t.Fatalf("Wrong error type %T: %s", err, err)
-	} else if len(uploadErr.Errors) != 1 {
+	} else if len(uploadErr) != 1 {
-		t.Fatalf("Unexpected number of errors: %d, expected 1", len(uploadErr.Errors))
+		t.Fatalf("Unexpected number of errors: %d, expected 1", len(uploadErr))
 	} else {
-		v2Err := uploadErr.Errors[0]
+		v2Err := uploadErr[0]
 		if v2Err.Code != v2.ErrorCodeBlobUploadInvalid {
 			t.Fatalf("Unexpected error code: %s, expected %d", v2Err.Code.String(), v2.ErrorCodeBlobUploadInvalid)
 		}
-		if expected := "invalid upload identifier"; v2Err.Message != expected {
+		if expected := "blob upload invalid"; v2Err.Message() != expected {
-			t.Fatalf("Unexpected error message: %s, expected %s", v2Err.Message, expected)
+			t.Fatalf("Unexpected error message: %s, expected %s", v2Err.Message(), expected)
 		}
 		if expected := "more detail"; v2Err.Detail.(string) != expected {
 			t.Fatalf("Unexpected error message: %s, expected %s", v2Err.Detail.(string), expected)

registry/client/errors.go

@@ -45,7 +45,7 @@ func parseHTTPErrorResponse(r io.Reader) error {
 			Response: body,
 		}
 	}
-	return &errors
+	return errors
 }
 
 func handleErrorResponse(resp *http.Response) error {
@@ -53,9 +53,8 @@ func handleErrorResponse(resp *http.Response) error {
 		err := parseHTTPErrorResponse(resp.Body)
 		if uErr, ok := err.(*UnexpectedHTTPResponseError); ok {
 			return &errcode.Error{
-				Code:    v2.ErrorCodeUnauthorized,
+				Code:   v2.ErrorCodeUnauthorized,
-				Message: "401 Unauthorized",
+				Detail: uErr.Response,
-				Detail:  uErr.Response,
 			}
 		}
 		return err

registry/client/repository_test.go

@@ -676,7 +676,7 @@ func TestManifestUnauthorized(t *testing.T) {
 	if v2Err.Code != v2.ErrorCodeUnauthorized {
 		t.Fatalf("Unexpected error code: %s", v2Err.Code.String())
 	}
-	if expected := "401 Unauthorized"; v2Err.Message != expected {
+	if expected := errcode.ErrorCode(v2.ErrorCodeUnauthorized).Message(); v2Err.Message() != expected {
-		t.Fatalf("Unexpected message value: %s, expected %s", v2Err.Message, expected)
+		t.Fatalf("Unexpected message value: %s, expected %s", v2Err.Message(), expected)
 	}
 }

registry/handlers/api_test.go

@@ -760,7 +760,7 @@ func checkBodyHasErrorCodes(t *testing.T, msg string, resp *http.Response, error
 		t.Fatalf("unexpected error decoding error response: %v", err)
 	}
 
-	if len(errs.Errors) == 0 {
+	if len(errs) == 0 {
 		t.Fatalf("expected errors in response")
 	}
 
@@ -780,7 +780,7 @@ func checkBodyHasErrorCodes(t *testing.T, msg string, resp *http.Response, error
 		counts[code] = 0
 	}
 
-	for _, err := range errs.Errors {
+	for _, err := range errs {
 		if _, ok := expected[err.Code]; !ok {
 			t.Fatalf("unexpected error code %v encountered during %s: %s ", err.Code, msg, string(p))
 		}

registry/handlers/app.go

@@ -346,9 +346,9 @@ func (app *App) dispatcher(dispatch dispatchFunc) http.Handler {
 
 				switch err := err.(type) {
 				case distribution.ErrRepositoryUnknown:
-					context.Errors.Push(v2.ErrorCodeNameUnknown, err)
+					context.Errors = append(context.Errors, errcode.NewError(v2.ErrorCodeNameUnknown, err))
 				case distribution.ErrRepositoryNameInvalid:
-					context.Errors.Push(v2.ErrorCodeNameInvalid, err)
+					context.Errors = append(context.Errors, errcode.NewError(v2.ErrorCodeNameInvalid, err))
 				}
 
 				serveJSON(w, context.Errors)
@@ -363,7 +363,7 @@ func (app *App) dispatcher(dispatch dispatchFunc) http.Handler {
 			context.Repository, err = applyRepoMiddleware(context.Repository, app.Config.Middleware["repository"])
 			if err != nil {
 				ctxu.GetLogger(context).Errorf("error initializing repository middleware: %v", err)
-				context.Errors.Push(errcode.ErrorCodeUnknown, err)
+				context.Errors = append(context.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 
 				serveJSON(w, context.Errors)
 				return
@@ -383,9 +383,9 @@ func (app *App) dispatcher(dispatch dispatchFunc) http.Handler {
 }
 
 func (app *App) logError(context context.Context, errors errcode.Errors) {
-	for _, e := range errors.Errors {
+	for _, e := range errors {
 		c := ctxu.WithValue(context, "err.code", e.Code)
-		c = ctxu.WithValue(c, "err.message", e.Message)
+		c = ctxu.WithValue(c, "err.message", e.Code.Message())
 		c = ctxu.WithValue(c, "err.detail", e.Detail)
 		c = ctxu.WithLogger(c, ctxu.GetLogger(c,
 			"err.code",
@@ -441,7 +441,7 @@ func (app *App) authorized(w http.ResponseWriter, r *http.Request, context *Cont
 			// proceed.
 
 			var errs errcode.Errors
-			errs.Push(v2.ErrorCodeUnauthorized)
+			errs = append(errs, errcode.NewError(v2.ErrorCodeUnauthorized))
 
 			serveJSON(w, errs)
 			return fmt.Errorf("forbidden: no repository name")
@@ -464,7 +464,7 @@ func (app *App) authorized(w http.ResponseWriter, r *http.Request, context *Cont
 			err.ServeHTTP(w, r)
 
 			var errs errcode.Errors
-			errs.Push(v2.ErrorCodeUnauthorized, accessRecords)
+			errs = append(errs, errcode.NewError(v2.ErrorCodeUnauthorized, accessRecords))
 			serveJSON(w, errs)
 		default:
 			// This condition is a potential security problem either in

registry/handlers/app_test.go

@@ -203,8 +203,8 @@ func TestNewApp(t *testing.T) {
 		t.Fatalf("error decoding error response: %v", err)
 	}
 
-	if errs.Errors[0].Code != v2.ErrorCodeUnauthorized {
+	if errs[0].Code != v2.ErrorCodeUnauthorized {
-		t.Fatalf("unexpected error code: %v != %v", errs.Errors[0].Code, v2.ErrorCodeUnauthorized)
+		t.Fatalf("unexpected error code: %v != %v", errs[0].Code, v2.ErrorCodeUnauthorized)
 	}
 }
 

registry/handlers/blob.go

@@ -18,12 +18,12 @@ func blobDispatcher(ctx *Context, r *http.Request) http.Handler {
 
 		if err == errDigestNotAvailable {
 			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				ctx.Errors.Push(v2.ErrorCodeDigestInvalid, err)
+				ctx.Errors = append(ctx.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, err))
 			})
 		}
 
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			ctx.Errors.Push(v2.ErrorCodeDigestInvalid, err)
+			ctx.Errors = append(ctx.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, err))
 		})
 	}
 
@@ -53,16 +53,16 @@ func (bh *blobHandler) GetBlob(w http.ResponseWriter, r *http.Request) {
 	desc, err := blobs.Stat(bh, bh.Digest)
 	if err != nil {
 		if err == distribution.ErrBlobUnknown {
-			bh.Errors.Push(v2.ErrorCodeBlobUnknown, bh.Digest)
+			bh.Errors = append(bh.Errors, errcode.NewError(v2.ErrorCodeBlobUnknown, bh.Digest))
 		} else {
-			bh.Errors.Push(errcode.ErrorCodeUnknown, err)
+			bh.Errors = append(bh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		}
 		return
 	}
 
 	if err := blobs.ServeBlob(bh, w, r, desc.Digest); err != nil {
 		context.GetLogger(bh).Debugf("unexpected error getting blob HTTP handler: %v", err)
-		bh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		bh.Errors = append(bh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 }

registry/handlers/blobupload.go

@@ -37,7 +37,7 @@ func blobUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
 		if err != nil {
 			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				ctxu.GetLogger(ctx).Infof("error resolving upload: %v", err)
-				buh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
+				buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadInvalid, err))
 			})
 		}
 		buh.State = state
@@ -45,14 +45,14 @@ func blobUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
 		if state.Name != ctx.Repository.Name() {
 			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				ctxu.GetLogger(ctx).Infof("mismatched repository name in upload state: %q != %q", state.Name, buh.Repository.Name())
-				buh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
+				buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadInvalid, err))
 			})
 		}
 
 		if state.UUID != buh.UUID {
 			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				ctxu.GetLogger(ctx).Infof("mismatched uuid in upload state: %q != %q", state.UUID, buh.UUID)
-				buh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
+				buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadInvalid, err))
 			})
 		}
 
@@ -62,12 +62,12 @@ func blobUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
 			ctxu.GetLogger(ctx).Errorf("error resolving upload: %v", err)
 			if err == distribution.ErrBlobUploadUnknown {
 				return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-					buh.Errors.Push(v2.ErrorCodeBlobUploadUnknown, err)
+					buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadUnknown, err))
 				})
 			}
 
 			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+				buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 			})
 		}
 		buh.Upload = upload
@@ -81,14 +81,14 @@ func blobUploadDispatcher(ctx *Context, r *http.Request) http.Handler {
 				defer upload.Close()
 				ctxu.GetLogger(ctx).Infof("error seeking blob upload: %v", err)
 				return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-					buh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
+					buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadInvalid, err))
 					upload.Cancel(buh)
 				})
 			} else if nn != buh.State.Offset {
 				defer upload.Close()
 				ctxu.GetLogger(ctx).Infof("seek to wrong offest: %d != %d", nn, buh.State.Offset)
 				return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-					buh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
+					buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadInvalid, err))
 					upload.Cancel(buh)
 				})
 			}
@@ -119,7 +119,7 @@ func (buh *blobUploadHandler) StartBlobUpload(w http.ResponseWriter, r *http.Req
 	blobs := buh.Repository.Blobs(buh)
 	upload, err := blobs.Create(buh)
 	if err != nil {
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
@@ -127,7 +127,7 @@ func (buh *blobUploadHandler) StartBlobUpload(w http.ResponseWriter, r *http.Req
 	defer buh.Upload.Close()
 
 	if err := buh.blobUploadResponse(w, r, true); err != nil {
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
@@ -138,7 +138,7 @@ func (buh *blobUploadHandler) StartBlobUpload(w http.ResponseWriter, r *http.Req
 // GetUploadStatus returns the status of a given upload, identified by id.
 func (buh *blobUploadHandler) GetUploadStatus(w http.ResponseWriter, r *http.Request) {
 	if buh.Upload == nil {
-		buh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
+		buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadUnknown))
 		return
 	}
 
@@ -146,7 +146,7 @@ func (buh *blobUploadHandler) GetUploadStatus(w http.ResponseWriter, r *http.Req
 	// resumable upload is supported. This will enable returning a non-zero
 	// range for clients to begin uploading at an offset.
 	if err := buh.blobUploadResponse(w, r, true); err != nil {
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
@@ -157,13 +157,13 @@ func (buh *blobUploadHandler) GetUploadStatus(w http.ResponseWriter, r *http.Req
 // PatchBlobData writes data to an upload.
 func (buh *blobUploadHandler) PatchBlobData(w http.ResponseWriter, r *http.Request) {
 	if buh.Upload == nil {
-		buh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
+		buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadUnknown))
 		return
 	}
 
 	ct := r.Header.Get("Content-Type")
 	if ct != "" && ct != "application/octet-stream" {
-		buh.Errors.Push(errcode.ErrorCodeUnknown, fmt.Errorf("Bad Content-Type"))
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, fmt.Errorf("Bad Content-Type")))
 		// TODO(dmcgowan): encode error
 		return
 	}
@@ -173,12 +173,12 @@ func (buh *blobUploadHandler) PatchBlobData(w http.ResponseWriter, r *http.Reque
 	// Copy the data
 	if _, err := io.Copy(buh.Upload, r.Body); err != nil {
 		ctxu.GetLogger(buh).Errorf("unknown error copying into upload: %v", err)
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
 	if err := buh.blobUploadResponse(w, r, false); err != nil {
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
@@ -192,7 +192,7 @@ func (buh *blobUploadHandler) PatchBlobData(w http.ResponseWriter, r *http.Reque
 // url of the blob.
 func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *http.Request) {
 	if buh.Upload == nil {
-		buh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
+		buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadUnknown))
 		return
 	}
 
@@ -200,21 +200,21 @@ func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *ht
 
 	if dgstStr == "" {
 		// no digest? return error, but allow retry.
-		buh.Errors.Push(v2.ErrorCodeDigestInvalid, "digest missing")
+		buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, "digest missing"))
 		return
 	}
 
 	dgst, err := digest.ParseDigest(dgstStr)
 	if err != nil {
 		// no digest? return error, but allow retry.
-		buh.Errors.Push(v2.ErrorCodeDigestInvalid, "digest parsing failed")
+		buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, "digest parsing failed"))
 		return
 	}
 
 	// Read in the data, if any.
 	if _, err := io.Copy(buh.Upload, r.Body); err != nil {
 		ctxu.GetLogger(buh).Errorf("unknown error copying into upload: %v", err)
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
@@ -229,14 +229,14 @@ func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *ht
 	if err != nil {
 		switch err := err.(type) {
 		case distribution.ErrBlobInvalidDigest:
-			buh.Errors.Push(v2.ErrorCodeDigestInvalid, err)
+			buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, err))
 		default:
 			switch err {
 			case distribution.ErrBlobInvalidLength, distribution.ErrBlobDigestUnsupported:
-				buh.Errors.Push(v2.ErrorCodeBlobUploadInvalid, err)
+				buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadInvalid, err))
 			default:
 				ctxu.GetLogger(buh).Errorf("unknown error completing upload: %#v", err)
-				buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+				buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 			}
 
 		}
@@ -253,7 +253,7 @@ func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *ht
 	// Build our canonical blob url
 	blobURL, err := buh.urlBuilder.BuildBlobURL(buh.Repository.Name(), desc.Digest)
 	if err != nil {
-		buh.Errors.Push(errcode.ErrorCodeUnknown, err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 
@@ -266,14 +266,14 @@ func (buh *blobUploadHandler) PutBlobUploadComplete(w http.ResponseWriter, r *ht
 // CancelBlobUpload cancels an in-progress upload of a blob.
 func (buh *blobUploadHandler) CancelBlobUpload(w http.ResponseWriter, r *http.Request) {
 	if buh.Upload == nil {
-		buh.Errors.Push(v2.ErrorCodeBlobUploadUnknown)
+		buh.Errors = append(buh.Errors, errcode.NewError(v2.ErrorCodeBlobUploadUnknown))
 		return
 	}
 
 	w.Header().Set("Docker-Upload-UUID", buh.UUID)
 	if err := buh.Upload.Cancel(buh); err != nil {
 		ctxu.GetLogger(buh).Errorf("error encountered canceling upload: %v", err)
-		buh.Errors.PushErr(err)
+		buh.Errors = append(buh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 	}
 
 	w.WriteHeader(http.StatusNoContent)

registry/handlers/helpers.go

@@ -14,8 +14,8 @@ func serveJSON(w http.ResponseWriter, v interface{}) error {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	sc := http.StatusInternalServerError
 
-	if errs, ok := v.(errcode.Errors); ok && errs.Len() > 0 {
+	if errs, ok := v.(errcode.Errors); ok && len(errs) > 0 {
-		sc = errs.Errors[0].Code.Descriptor().HTTPStatusCode
+		sc = errs[0].Code.Descriptor().HTTPStatusCode
 		if sc == 0 {
 			sc = http.StatusInternalServerError
 		}

registry/handlers/images.go

@@ -10,6 +10,7 @@ import (
 	ctxu "github.com/docker/distribution/context"
 	"github.com/docker/distribution/digest"
 	"github.com/docker/distribution/manifest"
+	"github.com/docker/distribution/registry/api/errcode"
 	"github.com/docker/distribution/registry/api/v2"
 	"github.com/gorilla/handlers"
 	"golang.org/x/net/context"
@@ -63,7 +64,7 @@ func (imh *imageManifestHandler) GetImageManifest(w http.ResponseWriter, r *http
 	}
 
 	if err != nil {
-		imh.Errors.Push(v2.ErrorCodeManifestUnknown, err)
+		imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeManifestUnknown, err))
 		return
 	}
 
@@ -71,7 +72,7 @@ func (imh *imageManifestHandler) GetImageManifest(w http.ResponseWriter, r *http
 	if imh.Digest == "" {
 		dgst, err := digestManifest(imh, sm)
 		if err != nil {
-			imh.Errors.Push(v2.ErrorCodeDigestInvalid, err)
+			imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, err))
 			return
 		}
 
@@ -92,13 +93,13 @@ func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http
 
 	var manifest manifest.SignedManifest
 	if err := dec.Decode(&manifest); err != nil {
-		imh.Errors.Push(v2.ErrorCodeManifestInvalid, err)
+		imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeManifestInvalid, err))
 		return
 	}
 
 	dgst, err := digestManifest(imh, &manifest)
 	if err != nil {
-		imh.Errors.Push(v2.ErrorCodeDigestInvalid, err)
+		imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid, err))
 		return
 	}
 
@@ -106,7 +107,7 @@ func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http
 	if imh.Tag != "" {
 		if manifest.Tag != imh.Tag {
 			ctxu.GetLogger(imh).Errorf("invalid tag on manifest payload: %q != %q", manifest.Tag, imh.Tag)
-			imh.Errors.Push(v2.ErrorCodeTagInvalid)
+			imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeTagInvalid))
 			return
 		}
 
@@ -114,11 +115,11 @@ func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http
 	} else if imh.Digest != "" {
 		if dgst != imh.Digest {
 			ctxu.GetLogger(imh).Errorf("payload digest does match: %q != %q", dgst, imh.Digest)
-			imh.Errors.Push(v2.ErrorCodeDigestInvalid)
+			imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid))
 			return
 		}
 	} else {
-		imh.Errors.Push(v2.ErrorCodeTagInvalid, "no tag or digest specified")
+		imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeTagInvalid, "no tag or digest specified"))
 		return
 	}
 
@@ -130,19 +131,19 @@ func (imh *imageManifestHandler) PutImageManifest(w http.ResponseWriter, r *http
 			for _, verificationError := range err {
 				switch verificationError := verificationError.(type) {
 				case distribution.ErrManifestBlobUnknown:
-					imh.Errors.Push(v2.ErrorCodeBlobUnknown, verificationError.Digest)
+					imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeBlobUnknown, verificationError.Digest))
 				case distribution.ErrManifestUnverified:
-					imh.Errors.Push(v2.ErrorCodeManifestUnverified)
+					imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeManifestUnverified))
 				default:
 					if verificationError == digest.ErrDigestInvalidFormat {
-						imh.Errors.Push(v2.ErrorCodeDigestInvalid)
+						imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeDigestInvalid))
 					} else {
-						imh.Errors.PushErr(verificationError)
+						imh.Errors = append(imh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, verificationError))
 					}
 				}
 			}
 		default:
-			imh.Errors.PushErr(err)
+			imh.Errors = append(imh.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		}
 
 		return
@@ -171,7 +172,7 @@ func (imh *imageManifestHandler) DeleteImageManifest(w http.ResponseWriter, r *h
 	// tag index entries a serious problem in eventually consistent storage.
 	// Once we work out schema version 2, the full deletion system will be
 	// worked out and we can add support back.
-	imh.Errors.Push(v2.ErrorCodeUnsupported)
+	imh.Errors = append(imh.Errors, errcode.NewError(v2.ErrorCodeUnsupported))
 }
 
 // digestManifest takes a digest of the given manifest. This belongs somewhere

registry/handlers/tags.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/docker/distribution"
+	"github.com/docker/distribution/registry/api/errcode"
 	"github.com/docker/distribution/registry/api/v2"
 	"github.com/gorilla/handlers"
 )
@@ -39,9 +40,9 @@ func (th *tagsHandler) GetTags(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		switch err := err.(type) {
 		case distribution.ErrRepositoryUnknown:
-			th.Errors.Push(v2.ErrorCodeNameUnknown, map[string]string{"name": th.Repository.Name()})
+			th.Errors = append(th.Errors, errcode.NewError(v2.ErrorCodeNameUnknown, map[string]string{"name": th.Repository.Name()}))
 		default:
-			th.Errors.PushErr(err)
+			th.Errors = append(th.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		}
 		return
 	}
@@ -53,7 +54,7 @@ func (th *tagsHandler) GetTags(w http.ResponseWriter, r *http.Request) {
 		Name: th.Repository.Name(),
 		Tags: tags,
 	}); err != nil {
-		th.Errors.PushErr(err)
+		th.Errors = append(th.Errors, errcode.NewError(errcode.ErrorCodeUnknown, err))
 		return
 	}
 }