looks like we got it

esti/s3_gateway_test.go

@@ -186,18 +186,6 @@ func TestS3UploadAndDownload(t *testing.T) {
 		})
 	}
 }
-func uploadMultipartCompleteIfNoneMatch(ctx context.Context, svc *s3.Client, resp *s3.CreateMultipartUploadOutput, completedParts []types.CompletedPart) (*s3.CompleteMultipartUploadOutput, error) {
-	completeInput := &s3.CompleteMultipartUploadInput{
-		Bucket:   resp.Bucket,
-		Key:      resp.Key,
-		UploadId: resp.UploadId,
-		MultipartUpload: &types.CompletedMultipartUpload{
-			Parts: completedParts,
-		},
-	}
-	return svc.CompleteMultipartUpload(ctx, completeInput)
-}
-
 func TestMultipartUploadIfNoneMatch(t *testing.T) {
 	// timeResolution is a duration greater than the timestamp resolution of the backing
 	// store.  Multipart object on S3 is the time of create-MPU, waiting before completion
@@ -272,9 +260,7 @@ func setHTTPHeaders(ifNoneMatch string) func(*middleware.Stack) error {
 			if req, ok := in.Request.(*smithyhttp.Request); ok {
 				// Add the If-None-Match header
 				req.Header.Set("If-None-Match", ifNoneMatch)
-				fmt.Printf("Set If-None-Match header: %s\n", ifNoneMatch) // Debug logging
 			}
-			// Continue with the next middleware handler
 			return next.HandleBuild(ctx, in)
 		}), middleware.Before)
 	}

pkg/gateway/operations/postobject.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/treeverse/lakefs/pkg/block"
+	"github.com/treeverse/lakefs/pkg/catalog"
 	gatewayErrors "github.com/treeverse/lakefs/pkg/gateway/errors"
 	"github.com/treeverse/lakefs/pkg/gateway/multipart"
 	"github.com/treeverse/lakefs/pkg/gateway/path"
@@ -94,15 +95,21 @@ func (controller *PostObject) HandleCompleteMultipartUpload(w http.ResponseWrite
 		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrInternalError))
 		return
 	}
-	allowOverWrite, err := o.checkIfAbsent(req)
-	if errors.Is(err, gatewayErrors.ErrPreconditionFailed) {
-		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrPreconditionFailed))
-		return
-	}
-	if errors.Is(err, gatewayErrors.ErrNotImplemented) {
+	// before completing multipart upload, check whether if-none-match header is added,
+	// in order to not overwrite object
+	allowOverwrite, err := o.checkIfAbsent(req)
+	if err != nil {
 		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrNotImplemented))
 		return
 	}
+	if !allowOverwrite {
+		_, err := o.Catalog.GetEntry(req.Context(), o.Repository.Name, o.Reference, o.Path, catalog.GetEntryParams{})
+		if err == nil {
+			// In case object exists in catalog, no error returns
+			_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrPreconditionFailed))
+			return
+		}
+	}
 	objName := multiPart.PhysicalAddress
 	req = req.WithContext(logging.AddFields(req.Context(), logging.Fields{logging.PhysicalAddressFieldKey: objName}))
 	xmlMultipartComplete, err := io.ReadAll(req.Body)
@@ -133,7 +140,7 @@ func (controller *PostObject) HandleCompleteMultipartUpload(w http.ResponseWrite
 		return
 	}
 	checksum := strings.Split(resp.ETag, "-")[0]
-	err = o.finishUpload(req, resp.MTime, checksum, objName, resp.ContentLength, true, multiPart.Metadata, multiPart.ContentType, allowOverWrite)
+	err = o.finishUpload(req, resp.MTime, checksum, objName, resp.ContentLength, true, multiPart.Metadata, multiPart.ContentType, allowOverwrite)
 	if errors.Is(err, graveler.ErrPreconditionFailed) {
 		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrPreconditionFailed))
 		return

pkg/gateway/operations/putobject.go

@@ -298,15 +298,21 @@ func handlePut(w http.ResponseWriter, req *http.Request, o *PathOperation) {
 	o.Incr("put_object", o.Principal, o.Repository.Name, o.Reference)
 	storageClass := StorageClassFromHeader(req.Header)
 	opts := block.PutOpts{StorageClass: storageClass}
-	allowOverWrite, err := o.checkIfAbsent(req)
-	if errors.Is(err, gatewayErrors.ErrPreconditionFailed) {
-		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrPreconditionFailed))
-		return
-	}
-	if errors.Is(err, gatewayErrors.ErrNotImplemented) {
+	// before uploading object, check whether if-none-match header is added,
+	// in order to not overwrite object
+	allowOverwrite, err := o.checkIfAbsent(req)
+	if err != nil {
 		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrNotImplemented))
 		return
 	}
+	if !allowOverwrite {
+		_, err := o.Catalog.GetEntry(req.Context(), o.Repository.Name, o.Reference, o.Path, catalog.GetEntryParams{})
+		if err == nil {
+			// In case object exists in catalog, no error returns
+			_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrPreconditionFailed))
+			return
+		}
+	}
 	address := o.PathProvider.NewPath()
 	blob, err := upload.WriteBlob(req.Context(), o.BlockStore, o.Repository.StorageNamespace, address, req.Body, req.ContentLength, opts)
 	if err != nil {
@@ -318,7 +324,7 @@ func handlePut(w http.ResponseWriter, req *http.Request, o *PathOperation) {
 	// write metadata
 	metadata := amzMetaAsMetadata(req)
 	contentType := req.Header.Get("Content-Type")
-	err = o.finishUpload(req, &blob.CreationDate, blob.Checksum, blob.PhysicalAddress, blob.Size, true, metadata, contentType, allowOverWrite)
+	err = o.finishUpload(req, &blob.CreationDate, blob.Checksum, blob.PhysicalAddress, blob.Size, true, metadata, contentType, allowOverwrite)
 	if errors.Is(err, graveler.ErrPreconditionFailed) {
 		_ = o.EncodeError(w, req, err, gatewayErrors.Codes.ToAPIErr(gatewayErrors.ErrPreconditionFailed))
 		return
@@ -340,20 +346,12 @@ func handlePut(w http.ResponseWriter, req *http.Request, o *PathOperation) {
 }
 
 func (o *PathOperation) checkIfAbsent(req *http.Request) (bool, error) {
-	Header := req.Header.Get(IfNoneMatchHeader)
-	if Header == "" {
+	headerValue := req.Header.Get(IfNoneMatchHeader)
+	if headerValue == "" {
 		return true, nil
 	}
-	if Header == "*" {
-		_, err := o.Catalog.GetEntry(req.Context(), o.Repository.Name, o.Reference, o.Path, catalog.GetEntryParams{})
-		if err == nil {
-			return false, gatewayErrors.ErrPreconditionFailed
-		}
-		if !errors.Is(err, graveler.ErrNotFound) {
-			return false, gatewayErrors.ErrInternalError
-		} else {
-			return true, nil
-		}
+	if headerValue == "*" {
+		return false, nil
 	}
 	return false, gatewayErrors.ErrNotImplemented
 }