gRPC Server: Make message size limits configurable. (#86982)

* gRPC Server: Make message size limits configurable.

* Fix mistake, don't add opts twice

* Apply suggestions from code review

Co-authored-by: Todd Treece <360020+toddtreece@users.noreply.github.com>

---------

Co-authored-by: Todd Treece <360020+toddtreece@users.noreply.github.com>

conf/defaults.ini

@@ -107,6 +107,12 @@ key_file =
 # this will log the request and response for each unary gRPC call
 enable_logging = false
 
+# Maximum size of a message that can be received in bytes. If not set, uses the gRPC default (4MiB).
+max_recv_msg_size =
+
+# Maximum size of a message that can be sent in bytes. If not set, uses the gRPC default (unlimited).
+max_send_msg_size =
+
 #################################### Database ############################
 [database]
 # You can configure the database connection by specifying type, host, name, user and password

conf/sample.ini

@@ -101,6 +101,8 @@
 ;use_tls = false
 ;cert_file =
 ;key_file =
+;max_recv_msg_size =
+;max_send_msg_size =
 
 #################################### Database ####################################
 [database]

pkg/services/grpcserver/service.go

@@ -85,12 +85,20 @@ func ProvideService(cfg *setting.Cfg, features featuremgmt.FeatureToggles, authe
 		opts = append(opts, grpc.Creds(credentials.NewTLS(cfg.GRPCServerTLSConfig)))
 	}
 
+	if s.cfg.GRPCServerMaxRecvMsgSize > 0 {
+		opts = append(opts, grpc.MaxRecvMsgSize(s.cfg.GRPCServerMaxRecvMsgSize))
+	}
+
+	if s.cfg.GRPCServerMaxSendMsgSize > 0 {
+		opts = append(opts, grpc.MaxSendMsgSize(s.cfg.GRPCServerMaxSendMsgSize))
+	}
+
 	s.server = grpc.NewServer(opts...)
 	return s, nil
 }
 
 func (s *gPRCServerService) Run(ctx context.Context) error {
-	s.logger.Info("Running GRPC server", "address", s.cfg.GRPCServerAddress, "network", s.cfg.GRPCServerNetwork, "tls", s.cfg.GRPCServerTLSConfig != nil)
+	s.logger.Info("Running GRPC server", "address", s.cfg.GRPCServerAddress, "network", s.cfg.GRPCServerNetwork, "tls", s.cfg.GRPCServerTLSConfig != nil, "max_recv_msg_size", s.cfg.GRPCServerMaxRecvMsgSize, "max_send_msg_size", s.cfg.GRPCServerMaxSendMsgSize)
 
 	listener, err := net.Listen(s.cfg.GRPCServerNetwork, s.cfg.GRPCServerAddress)
 	if err != nil {

pkg/setting/setting.go

@@ -470,10 +470,12 @@ type Cfg struct {
 	RBACSingleOrganization bool
 
 	// GRPC Server.
-	GRPCServerNetwork       string
+	GRPCServerNetwork        string
-	GRPCServerAddress       string
+	GRPCServerAddress        string
-	GRPCServerTLSConfig     *tls.Config
+	GRPCServerTLSConfig      *tls.Config
-	GRPCServerEnableLogging bool // log request and response of each unary gRPC call
+	GRPCServerEnableLogging  bool // log request and response of each unary gRPC call
+	GRPCServerMaxRecvMsgSize int
+	GRPCServerMaxSendMsgSize int
 
 	CustomResponseHeaders map[string]string
 
@@ -1769,6 +1771,8 @@ func readGRPCServerSettings(cfg *Cfg, iniFile *ini.File) error {
 	cfg.GRPCServerNetwork = valueAsString(server, "network", "tcp")
 	cfg.GRPCServerAddress = valueAsString(server, "address", "")
 	cfg.GRPCServerEnableLogging = server.Key("enable_logging").MustBool(false)
+	cfg.GRPCServerMaxRecvMsgSize = server.Key("max_recv_msg_size").MustInt(0)
+	cfg.GRPCServerMaxSendMsgSize = server.Key("max_send_msg_size").MustInt(0)
 	switch cfg.GRPCServerNetwork {
 	case "unix":
 		if cfg.GRPCServerAddress != "" {