feat: add configurations for keep alive on grpc server

configs/service.yaml

@@ -15,6 +15,11 @@ redis_max_retry_backoff: "512ms"
 
 blob_max_inline_size: 65536
 
+grpc_keepalive_max_connection_idle: "5m"
+grpc_keepalive_max_connection_age: "12h"
+grpc_keepalive_max_connection_age_grace: "5m"
+grpc_keepalive_time: "1h"
+grpc_keepalive_timeout: "20s"
 # The following enables OpenCensus Tracing via Cloud Trace
 # for the Datastore client library.
 # It is EXPERIMENTAL and subject to change or removal without notice.

internal/app/server/server.go

@@ -16,6 +16,7 @@ package server
 
 import (
 	"context"
+	"google.golang.org/grpc/keepalive"
 	"net"
 	"os"
 	"os/signal"
@@ -48,7 +49,18 @@ func Run(ctx context.Context, network string, cfg *config.ServiceConfig) error {
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
 
-	s := grpc.NewServer()
+	grpcOptions := []grpc.ServerOption{
+		grpc.KeepaliveParams(keepalive.ServerParameters{
+			MaxConnectionIdle:     cfg.GRPCServerConfig.MaxConnectionIdle,
+			MaxConnectionAge:      cfg.GRPCServerConfig.MaxConnectionAge,
+			MaxConnectionAgeGrace: cfg.GRPCServerConfig.MaxConnectionAgeGrace,
+			Time:                  cfg.GRPCServerConfig.Time,
+			Timeout:               cfg.GRPCServerConfig.Timeout,
+		}),
+	}
+
+	s := grpc.NewServer(grpcOptions...)
+
 	healthcheck := health.NewServer()
 	healthcheck.SetServingStatus(serviceName, healthgrpc.HealthCheckResponse_SERVING)
 	healthgrpc.RegisterHealthServer(s, healthcheck)

internal/pkg/config/loader.go

@@ -129,10 +129,19 @@ func Load(path string) (*ServiceConfig, error) {
 		MaxInlineSize: viper.GetInt(BlobMaxInlineSize),
 	}
 
+	grpcServerConfig := GRPCServerConfig{
+		MaxConnectionIdle:     viper.GetDuration(GRPCKeepAliveMaxConnectionIdle),
+		MaxConnectionAge:      viper.GetDuration(GRPCKeepAliveMaxConnectionAge),
+		MaxConnectionAgeGrace: viper.GetDuration(GRPCKeepAliveMaxConnectionAgeGrace),
+		Time:                  viper.GetDuration(GRPCKeepAliveTime),
+		Timeout:               viper.GetDuration(GRPCKeepAliveTimeout),
+	}
+
 	return &ServiceConfig{
-		ServerConfig: serverConfig,
-		CacheConfig:  cacheConfig,
-		RedisConfig:  redisConfig,
-		BlobConfig:   blobConfig,
+		ServerConfig:     serverConfig,
+		CacheConfig:      cacheConfig,
+		RedisConfig:      redisConfig,
+		BlobConfig:       blobConfig,
+		GRPCServerConfig: grpcServerConfig,
 	}, nil
 }

internal/pkg/config/model.go

@@ -36,6 +36,12 @@ const (
 
 	BlobMaxInlineSize = "blob_max_inline_size"
 
+	GRPCKeepAliveMaxConnectionIdle     = "grpc_keepalive_max_connection_idle"
+	GRPCKeepAliveMaxConnectionAge      = "grpc_keepalive_max_connection_age"
+	GRPCKeepAliveMaxConnectionAgeGrace = "grpc_keepalive_max_connection_age_grace"
+	GRPCKeepAliveTime                  = "grpc_keepalive_time"
+	GRPCKeepAliveTimeout               = "grpc_keepalive_timeout"
+
 	// The following enables OpenCensus Tracing via Cloud Trace
 	// for the Datastore client library.
 	// It is EXPERIMENTAL and subject to change or removal without notice.
@@ -48,6 +54,7 @@ type ServiceConfig struct {
 	CacheConfig
 	RedisConfig
 	BlobConfig
+	GRPCServerConfig
 }
 
 // ServerConfig defines common fields needed to start Open Saves.
@@ -87,3 +94,13 @@ type RedisConfig struct {
 type BlobConfig struct {
 	MaxInlineSize int
 }
+
+// GRPCServerConfig has the configurations for grpc server, for now keepAlive parameters
+// all the parameters are handled in time.Duration
+type GRPCServerConfig struct {
+	MaxConnectionIdle     time.Duration
+	MaxConnectionAge      time.Duration
+	MaxConnectionAgeGrace time.Duration
+	Time                  time.Duration
+	Timeout               time.Duration
+}