[#1183] node: Use NATS client as notification writer

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

cmd/neofs-node/notificator.go

@@ -9,22 +9,12 @@ import (
 	"github.com/nspcc-dev/neofs-node/pkg/morph/event"
 	"github.com/nspcc-dev/neofs-node/pkg/morph/event/netmap"
 	"github.com/nspcc-dev/neofs-node/pkg/services/notificator"
+	"github.com/nspcc-dev/neofs-node/pkg/services/notificator/nats"
 	objectSDK "github.com/nspcc-dev/neofs-sdk-go/object"
 	addressSDK "github.com/nspcc-dev/neofs-sdk-go/object/address"
 	"go.uber.org/zap"
 )
 
-type simpleNotificationWriter struct {
-	l *zap.Logger
-}
-
-func (s simpleNotificationWriter) Notify(topic string, address *addressSDK.Address) {
-	s.l.Debug("got notification to write",
-		zap.String("topic", topic),
-		zap.Stringer("address", address),
-	)
-}
-
 type notificationSource struct {
 	e            *engine.StorageEngine
 	l            *zap.Logger
@@ -101,12 +91,44 @@ func (n *notificationSource) processAddress(
 	return nil
 }
 
+type notificationWriter struct {
+	l *zap.Logger
+	w *nats.Writer
+}
+
+func (n notificationWriter) Notify(topic string, address *addressSDK.Address) {
+	if err := n.w.Notify(topic, address); err != nil {
+		n.l.Warn("could not write object notification",
+			zap.Stringer("address", address),
+			zap.String("topic", topic),
+			zap.Error(err),
+		)
+	}
+}
+
 func initNotification(c *cfg) {
 	if nodeconfig.Notification(c.appCfg).Enabled() {
 		topic := nodeconfig.Notification(c.appCfg).DefaultTopic()
+		pubKey := base58.Encode(c.cfgNodeInfo.localInfo.PublicKey())
 
 		if topic == "" {
-			topic = base58.Encode(c.cfgNodeInfo.localInfo.PublicKey())
+			topic = pubKey
+		}
+
+		natsSvc, err := nats.New(
+			c.ctx,
+			nodeconfig.Notification(c.appCfg).Endpoint(),
+			nats.WithConnectionName("NeoFS Storage Node: "+pubKey), // connection name is used in the server side logs
+			nats.WithTimeout(nodeconfig.Notification(c.appCfg).Timeout()),
+			nats.WithClientCert(
+				nodeconfig.Notification(c.appCfg).CertPath(),
+				nodeconfig.Notification(c.appCfg).KeyPath(),
+			),
+			nats.WithRootCA(nodeconfig.Notification(c.appCfg).CAPath()),
+			nats.WithLogger(c.log),
+		)
+		if err != nil {
+			panic("could not created object notificator: " + err.Error())
 		}
 
 		n := notificator.New(new(notificator.Prm).
@@ -117,7 +139,10 @@ func initNotification(c *cfg) {
 					l:            c.log,
 					defaultTopic: topic,
 				}).
-			SetWriter(simpleNotificationWriter{l: c.log}),
+			SetWriter(notificationWriter{
+				l: c.log,
+				w: natsSvc,
+			}),
 		)
 
 		addNewEpochAsyncNotificationHandler(c, func(e event.Event) {