feat: propagate detailed error msgs to client (OCI dist-spec format) (#1681)

Signed-off-by: Alexei Dodon <adodon@cisco.com>

pkg/storage/common/common.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"math/rand"
 	"path"
@@ -27,8 +28,7 @@ import (
 
 const (
 	manifestWithEmptyLayersErrMsg = "layers: Array must have at least 1 items"
-
-	cosignSignatureTagSuffix = "sig"
+	cosignSignatureTagSuffix      = "sig"
 )
 
 func GetTagsByIndex(index ispec.Index) []string {
@@ -86,7 +86,7 @@ func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaTy
 		if err := ValidateManifestSchema(body); err != nil {
 			log.Error().Err(err).Msg("OCIv1 image manifest schema validation failed")
 
-			return "", zerr.ErrBadManifest
+			return "", zerr.NewError(zerr.ErrBadManifest).AddDetail("jsonSchemaValidation", err.Error())
 		}
 
 		if err := json.Unmarshal(body, &manifest); err != nil {
@@ -125,7 +125,7 @@ func ValidateManifest(imgStore storageTypes.ImageStore, repo, reference, mediaTy
 		if err := ValidateImageIndexSchema(body); err != nil {
 			log.Error().Err(err).Msg("OCIv1 image index manifest schema validation failed")
 
-			return "", err
+			return "", zerr.NewError(zerr.ErrBadManifest).AddDetail("jsonSchemaValidation", err.Error())
 		}
 
 		var indexManifest ispec.Index
@@ -219,8 +219,10 @@ func CheckIfIndexNeedsUpdate(index *ispec.Index, desc *ispec.Descriptor,
 				log.Error().Err(err).
 					Str("old mediaType", manifest.MediaType).
 					Str("new mediaType", desc.MediaType).Msg("cannot change media-type")
+				reason := fmt.Sprintf("changing manifest media-type from \"%s\" to \"%s\" is disallowed",
+					manifest.MediaType, desc.MediaType)
 
-				return false, "", err
+				return false, "", zerr.NewError(err).AddDetail("reason", reason)
 			}
 
 			oldDesc := *desc
@@ -780,7 +782,7 @@ func IsNonDistributable(mediaType string) bool {
 func ValidateManifestSchema(buf []byte) error {
 	if err := schema.ValidatorMediaTypeManifest.Validate(bytes.NewBuffer(buf)); err != nil {
 		if !IsEmptyLayersError(err) {
-			return zerr.ErrBadManifest
+			return err
 		}
 	}
 
@@ -789,7 +791,7 @@ func ValidateManifestSchema(buf []byte) error {
 
 func ValidateImageIndexSchema(buf []byte) error {
 	if err := schema.ValidatorMediaTypeImageIndex.Validate(bytes.NewBuffer(buf)); err != nil {
-		return zerr.ErrBadManifest
+		return err
 	}
 
 	return nil

pkg/storage/common/common_test.go

@@ -3,6 +3,7 @@ package storage_test
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"os"
 	"testing"
 
@@ -12,7 +13,7 @@ import (
 	"github.com/rs/zerolog"
 	. "github.com/smartystreets/goconvey/convey"
 
-	"zotregistry.io/zot/errors"
+	zerr "zotregistry.io/zot/errors"
 	"zotregistry.io/zot/pkg/extensions/monitoring"
 	"zotregistry.io/zot/pkg/log"
 	"zotregistry.io/zot/pkg/storage"
@@ -74,6 +75,10 @@ func TestValidateManifest(t *testing.T) {
 
 			_, _, err = imgStore.PutImageManifest("test", "1.0", ispec.MediaTypeImageManifest, body)
 			So(err, ShouldNotBeNil)
+			var internalErr *zerr.Error
+			So(errors.As(err, &internalErr), ShouldBeTrue)
+			So(internalErr.GetDetails(), ShouldContainKey, "jsonSchemaValidation")
+			So(internalErr.GetDetails()["jsonSchemaValidation"], ShouldEqual, "[schemaVersion: Must be less than or equal to 2]")
 		})
 
 		Convey("manifest with non-distributable layers", func() {
@@ -169,7 +174,7 @@ func TestGetReferrersErrors(t *testing.T) {
 					return indexBuf, nil
 				},
 				GetBlobContentFn: func(repo string, digest godigest.Digest) ([]byte, error) {
-					return []byte{}, errors.ErrBlobNotFound
+					return []byte{}, zerr.ErrBlobNotFound
 				},
 			}
 
@@ -188,7 +193,7 @@ func TestGetReferrersErrors(t *testing.T) {
 					return indexBuf, nil
 				},
 				GetBlobContentFn: func(repo string, digest godigest.Digest) ([]byte, error) {
-					return []byte{}, errors.ErrBadBlob
+					return []byte{}, zerr.ErrBadBlob
 				},
 			}
 
@@ -363,7 +368,7 @@ func TestGetImageIndexErrors(t *testing.T) {
 	Convey("Trigger GetBlobContent error", t, func(c C) {
 		imgStore := &mocks.MockedImageStore{
 			GetBlobContentFn: func(repo string, digest godigest.Digest) ([]byte, error) {
-				return []byte{}, errors.ErrBlobNotFound
+				return []byte{}, zerr.ErrBlobNotFound
 			},
 		}