[#125] Fixed bucket creation

Bucket should has unique name.

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

api/handler/put.go

@@ -124,6 +124,7 @@ func (h *handler) CreateBucketHandler(w http.ResponseWriter, r *http.Request) {
 			Description:    err.Error(),
 			HTTPStatusCode: http.StatusInternalServerError,
 		}, r.URL)
+		return
 	}
 
 	h.log.Info("bucket is created",

api/layer/layer.go

@@ -127,6 +127,8 @@ var (
 	ErrObjectExists = errors.New("object exists")
 	// ErrObjectNotExists is returned on attempts to work with non-existing object.
 	ErrObjectNotExists = errors.New("object not exists")
+	// ErrBucketAlreadyExists is returned on attempts to create already existing bucket.
+	ErrBucketAlreadyExists = errors.New("bucket exists")
 )
 
 const (
@@ -491,7 +493,17 @@ func (n *layer) DeleteObjects(ctx context.Context, bucket string, objects []stri
 }
 
 func (n *layer) CreateBucket(ctx context.Context, p *CreateBucketParams) (*cid.ID, error) {
+	_, err := n.GetBucketInfo(ctx, p.Name)
+	if err != nil {
+		errMsg := err.Error()
+		if strings.Contains(errMsg, "bucket not found") ||
+			strings.Contains(errMsg, "container not found") {
 			return n.createContainer(ctx, p)
+		}
+		return nil, err
+	}
+
+	return nil, ErrBucketAlreadyExists
 }
 
 func (n *layer) DeleteBucket(ctx context.Context, p *DeleteBucketParams) error {