fix:#56 added update for grpc

services/ical/service/connector/grpc/client.go

@@ -19,14 +19,31 @@ package grpc
 import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/keepalive"
 	"log/slog"
+	"sync"
+	"time"
 )
 
+var conn *grpc.ClientConn
+var once sync.Once
+
 func ConnectGRPCServer(host string) *grpc.ClientConn {
-	conn, err := grpc.NewClient(host+":50051", grpc.WithTransportCredentials(insecure.NewCredentials()))
-	if err != nil {
-		slog.Error("could not connect to grpc server", "error", err)
-	}
+	once.Do(func() {
+		var err error
+		conn, err = grpc.NewClient(
+			host+":50051",
+			grpc.WithTransportCredentials(insecure.NewCredentials()),
+			grpc.WithKeepaliveParams(keepalive.ClientParameters{
+				Time:                2 * time.Minute,
+				Timeout:             20 * time.Second,
+				PermitWithoutStream: true,
+			}),
+		)
+		if err != nil {
+			slog.Error("could not connect to grpc server", "error", err)
+		}
+	})
 	return conn
 }