Use custom grpc logger (#1241)

Suppress ServerMetadata error log on routing error.

server/api.go

@@ -24,6 +24,7 @@ import (
 	"database/sql"
 	"encoding/base64"
 	"fmt"
+	"google.golang.org/grpc/grpclog"
 	"math"
 	"net"
 	"net/http"
@@ -112,6 +113,10 @@ func StartApiServer(logger *zap.Logger, startupLogger *zap.Logger, db *sql.DB, p
 	}
 	grpcServer := grpc.NewServer(serverOpts...)
 
+	// Set grpc logger
+	grpcLogger := NewGrpcCustomLogger(logger)
+	grpclog.SetLoggerV2(grpcLogger)
+
 	s := &ApiServer{
 		logger:               logger,
 		db:                   db,
@@ -151,6 +156,7 @@ func StartApiServer(logger *zap.Logger, startupLogger *zap.Logger, db *sql.DB, p
 	// Should start after GRPC server itself because RegisterNakamaHandlerFromEndpoint below tries to dial GRPC.
 	ctx := context.Background()
 	grpcGateway := grpcgw.NewServeMux(
+		grpcgw.WithRoutingErrorHandler(handleRoutingError),
 		grpcgw.WithMetadata(func(ctx context.Context, r *http.Request) metadata.MD {
 			// For RPC GET operations pass through any custom query parameters.
 			if r.Method != "GET" || !strings.HasPrefix(r.URL.Path, "/v2/rpc/") {
@@ -166,7 +172,7 @@ func StartApiServer(logger *zap.Logger, startupLogger *zap.Logger, db *sql.DB, p
 				}
 				p["q_"+k] = vs
 			}
-			return metadata.MD(p)
+			return p
 		}),
 		grpcgw.WithMarshalerOption(grpcgw.MIMEWildcard, &grpcgw.HTTPBodyMarshaler{
 			Marshaler: &grpcgw.JSONPb{
@@ -594,3 +600,18 @@ func traceApiAfter(ctx context.Context, logger *zap.Logger, metrics Metrics, ful
 
 	metrics.ApiAfter(fullMethodName, time.Since(start), err != nil)
 }
+
+func handleRoutingError(ctx context.Context, mux *grpcgw.ServeMux, marshaler grpcgw.Marshaler, w http.ResponseWriter, r *http.Request, httpStatus int) {
+	sterr := status.Error(codes.Internal, "Unexpected routing error")
+	switch httpStatus {
+	case http.StatusBadRequest:
+		sterr = status.Error(codes.InvalidArgument, http.StatusText(httpStatus))
+	case http.StatusMethodNotAllowed:
+		sterr = status.Error(codes.Unimplemented, http.StatusText(httpStatus))
+	case http.StatusNotFound:
+		sterr = status.Error(codes.NotFound, http.StatusText(httpStatus))
+	}
+
+	// Set empty ServerMetadata to prevent logging error on nil metadata.
+	grpcgw.DefaultHTTPErrorHandler(grpcgw.NewServerMetadataContext(ctx, grpcgw.ServerMetadata{}), mux, marshaler, w, r, sterr)
+}

server/logger.go

@@ -219,3 +219,31 @@ func RedirectStdLog(logger *zap.Logger) {
 	skipLogger := logger.WithOptions(zap.AddCallerSkip(3))
 	log.SetOutput(&RedirectStdLogWriter{skipLogger})
 }
+
+type grpcCustomLogger struct {
+	*zap.SugaredLogger
+}
+
+// https://github.com/grpc/grpc-go/blob/master/grpclog/loggerv2.go
+func NewGrpcCustomLogger(logger *zap.Logger) grpcCustomLogger {
+	sLogger := logger.Sugar()
+	return grpcCustomLogger{
+		sLogger,
+	}
+}
+
+func (g grpcCustomLogger) Warning(args ...any) {
+	g.Warn(args...)
+}
+
+func (g grpcCustomLogger) Warningln(args ...any) {
+	g.Warnln(args...)
+}
+
+func (g grpcCustomLogger) Warningf(format string, args ...any) {
+	g.Warnf(format, args...)
+}
+
+func (g grpcCustomLogger) V(l int) bool {
+	return int(g.Level()) <= l
+}