add Search_Config validation

internal/errors/lb.go

@@ -25,4 +25,7 @@ var (
 
 	// ErrIndexNotFound represents an error that the index not found.
 	ErrIndexNotFound = New("index not found")
+
+	// ErrNilSearch_Config represents an error that the Search_Config is nil.
+	ErrNilSearch_Config = New("Search_Config is nil")
 )

pkg/gateway/lb/handler/grpc/aggregation.go

@@ -65,6 +65,10 @@ func (s *server) aggregationSearch(
 		}
 	}()
 
+	if bcfg == nil {
+		return nil, nil, errors.ErrNilSearch_Config
+	}
+
 	num := aggr.GetNum()
 	min := int(bcfg.GetMinNum())
 

pkg/gateway/lb/handler/grpc/handler.go

@@ -438,6 +438,28 @@ func (s *server) doSearch(
 		}
 	}()
 
+	if cfg == nil {
+		err = errors.ErrNilSearch_Config
+		err = status.WrapWithInvalidArgument(apiName+"/doSearch", err, &errdetails.RequestInfo{
+			RequestId:   "Search_Config is nil",
+			ServingData: "Search_Config is nil",
+		},
+			&errdetails.BadRequest{
+				FieldViolations: []*errdetails.BadRequestFieldViolation{
+					{
+						Field:       "Search_Config is nil",
+						Description: err.Error(),
+					},
+				},
+			})
+		if span != nil {
+			span.RecordError(err)
+			span.SetAttributes(trace.StatusCodeInvalidArgument(err.Error())...)
+			span.SetStatus(trace.StatusError, err.Error())
+		}
+		return nil, nil, err
+	}
+
 	var (
 		num     = int(cfg.GetNum())
 		fnum    int