[sovereign] Add config option to disable notifier

cmd/sovereignnode/config/sovereignConfig.toml

@@ -45,6 +45,13 @@
     Hasher = "sha256"
 
 [NotifierConfig]
+    # This flag indicates whether the node will establish a WebSocket receiver connection from a light node or observer.
+    # Running an additional main chain light node as a notifier requires extra hardware resources.
+    # When disabled, the node will rely on and trust incoming headers from the main chain proposed by other leaders.
+    # Disabling this flag can be useful in scenarios where additional validation infrastructure isn't necessary,
+    # such as for a CEX observer setup that only requires balance checks on various addresses.
+    Enabled = true
+
     SubscribedEvents = [
         { Identifier = "deposit", Addresses = ["erd1qyu5wthldzr8wx5c9ucg8kjagg0jfs53s8nr3zpz3hypefsdd8ssycr6th"] },
         { Identifier = "execute", Addresses = ["erd1qyu5wthldzr8wx5c9ucg8kjagg0jfs53s8nr3zpz3hypefsdd8ssycr6th"] }

cmd/sovereignnode/sovereignNodeRunner.go

@@ -529,25 +529,12 @@ func (snr *sovereignNodeRunner) executeOneComponentCreationCycle(
 		return true, err
 	}
 
-	sovereignNotifier, err := createSovereignNotifier(&configs.SovereignExtraConfig.NotifierConfig)
-	if err != nil {
-		return true, err
-	}
-
-	sovereignWsReceiver, err := createSovereignWsReceiver(
-		&configs.SovereignExtraConfig.NotifierConfig,
-		sovereignNotifier,
-	)
-	if err != nil {
-		return true, err
-	}
-
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
 
-	sovereignNotifierBootstrapper, err := startSovereignNotifierBootstrapper(
+	notifierServices, err := createNotifierWSReceiverServicesIfNeeded(
+		&configs.SovereignExtraConfig.NotifierConfig,
 		incomingHeaderHandler,
-		sovereignNotifier,
 		managedCoreComponents.GenesisNodesSetup().GetRoundDuration(),
 		managedProcessComponents.ForkDetector(),
 		managedConsensusComponents.Bootstrapper(),
@@ -559,18 +546,17 @@ func (snr *sovereignNodeRunner) executeOneComponentCreationCycle(
 
 	log.Debug("creating node structure")
 
-	extraOptionNotifierReceiver := func(n *node.Node) error {
-		n.AddClosableComponent(sovereignWsReceiver)
+	extraOptionsNotifier := func(n *node.Node) error {
+		for _, notifierService := range notifierServices {
+			n.AddClosableComponent(notifierService)
+		}
+
 		return nil
 	}
 	extraOptionOutGoingBridgeSender := func(n *node.Node) error {
 		n.AddClosableComponent(outGoingBridgeOpHandler)
 		return nil
 	}
-	extraOptionNotifierBootstrapper := func(n *node.Node) error {
-		n.AddClosableComponent(sovereignNotifierBootstrapper)
-		return nil
-	}
 
 	nodeHandler, err := node.CreateNode(
 		configs.GeneralConfig,
@@ -589,9 +575,8 @@ func (snr *sovereignNodeRunner) executeOneComponentCreationCycle(
 		flagsConfig.BootstrapRoundIndex,
 		configs.ImportDbConfig.IsImportDBMode,
 		node.NewSovereignNodeFactory(configs.GeneralConfig.SovereignConfig.GenesisConfig.NativeESDT),
-		extraOptionNotifierReceiver,
+		extraOptionsNotifier,
 		extraOptionOutGoingBridgeSender,
-		extraOptionNotifierBootstrapper,
 	)
 	if err != nil {
 		return true, err
@@ -1905,6 +1890,46 @@ func createWhiteListerVerifiedTxs(generalConfig *config.Config) (process.WhiteLi
 	return interceptors.NewWhiteListDataVerifier(whiteListCacheVerified)
 }
 
+func createNotifierWSReceiverServicesIfNeeded(
+	config *config.NotifierConfig,
+	incomingHeaderHandler process.IncomingHeaderSubscriber,
+	roundDuration uint64,
+	forkDetector process.ForkDetector,
+	bootstrapper process.Bootstrapper,
+	sigStopNode chan os.Signal,
+) ([]mainFactory.Closer, error) {
+	if !config.Enabled {
+		log.Info("running without any notifier attached")
+		return make([]mainFactory.Closer, 0), nil
+	}
+
+	sovereignNotifier, err := createSovereignNotifier(config)
+	if err != nil {
+		return nil, err
+	}
+
+	sovereignWsReceiver, err := createSovereignWsReceiver(
+		config,
+		sovereignNotifier,
+	)
+	if err != nil {
+		return nil, err
+	}
+	sovereignNotifierBootstrapper, err := startSovereignNotifierBootstrapper(
+		incomingHeaderHandler,
+		sovereignNotifier,
+		roundDuration,
+		forkDetector,
+		bootstrapper,
+		sigStopNode,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return []mainFactory.Closer{sovereignWsReceiver, sovereignNotifierBootstrapper}, nil
+}
+
 func createSovereignWsReceiver(
 	config *config.NotifierConfig,
 	sovereignNotifier notifierProcess.SovereignNotifier,

config/sovereignConfig.go

@@ -38,6 +38,7 @@ type OutGoingBridgeCertificate struct {
 
 // NotifierConfig holds sovereign notifier configuration
 type NotifierConfig struct {
+	Enabled          bool              `toml:"Enabled"`
 	SubscribedEvents []SubscribedEvent `toml:"SubscribedEvents"`
 	WebSocketConfig  WebSocketConfig   `toml:"WebSocket"`
 }