feat(go): expose runtime ingest metrics

go/vehicle-gateway/cmd/nats-kafka-bridge/main.go

@@ -18,6 +18,7 @@ import (
 
 	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
 	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/health"
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/metrics"
 	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/observability"
 )
 
@@ -33,6 +34,7 @@ func main() {
 		os.Exit(1)
 	}
 	defer conn.Close()
+	registry := metrics.NewRegistry()
 	health.Start(ctx, logger, health.NewServer(env("HEALTH_ADDR", ""), "nats-kafka-bridge", []health.Check{
 		{Name: "nats", Check: func(context.Context) error {
 			if conn.Status() != nats.CONNECTED {
@@ -40,7 +42,7 @@ func main() {
 			}
 			return nil
 		}},
-	}))
+	}, registry))
 	js, err := conn.JetStream()
 	if err != nil {
 		logger.Error("nats jetstream init failed", "error", err)
@@ -78,7 +80,7 @@ func main() {
 		"durable", cfg.NATSDurable,
 		"filter", cfg.NATSFilter,
 		"kafka_brokers", strings.Join(cfg.KafkaBrokers, ","))
-	runBridge(ctx, logger, sub, writer, cfg)
+	runBridge(ctx, logger, registry, sub, writer, cfg)
 }
 
 type config struct {
@@ -135,7 +137,7 @@ type bridgeMessage struct {
 	ack     func() error
 }
 
-func runBridge(ctx context.Context, logger *slog.Logger, sub natsPullSubscription, writer kafkaBatchWriter, cfg config) {
+func runBridge(ctx context.Context, logger *slog.Logger, registry *metrics.Registry, sub natsPullSubscription, writer kafkaBatchWriter, cfg config) {
 	for {
 		if ctx.Err() != nil {
 			return
@@ -161,7 +163,7 @@ func runBridge(ctx context.Context, logger *slog.Logger, sub natsPullSubscriptio
 			})
 		}
 		operationCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), cfg.OperationWait)
-		err = bridgeBatch(operationCtx, writer, bridgeMessages, cfg.Route)
+		err = bridgeBatch(operationCtx, registry, writer, bridgeMessages, cfg.Route)
 		cancel()
 		if err != nil {
 			logger.Error("bridge batch failed", "count", len(bridgeMessages), "error", err)
@@ -194,32 +196,56 @@ func ensureStream(js nats.JetStreamContext, cfg config) error {
 	return err
 }
 
-func bridgeBatch(ctx context.Context, writer kafkaBatchWriter, messages []bridgeMessage, route map[string]string) error {
+func bridgeBatch(ctx context.Context, registry *metrics.Registry, writer kafkaBatchWriter, messages []bridgeMessage, route map[string]string) error {
 	if len(messages) == 0 {
 		return nil
 	}
 	kafkaMessages := make([]kafka.Message, 0, len(messages))
 	for _, message := range messages {
+		addBridgeSubjectMetric(registry, "vehicle_bridge_messages_total", message.subject, "received")
 		topic, ok := route[message.subject]
 		if !ok || topic == "" {
+			addBridgeSubjectMetric(registry, "vehicle_bridge_messages_total", message.subject, "route_error")
 			return fmt.Errorf("kafka topic not configured for nats subject %q", message.subject)
 		}
 		kafkaMessages = append(kafkaMessages, kafkaMessage(topic, message.data))
 	}
 	if err := writer.WriteMessages(ctx, kafkaMessages...); err != nil {
+		for _, message := range kafkaMessages {
+			addBridgeTopicMetric(registry, "vehicle_bridge_kafka_writes_total", message.Topic, "error")
+		}
 		return err
 	}
+	for _, message := range kafkaMessages {
+		addBridgeTopicMetric(registry, "vehicle_bridge_kafka_writes_total", message.Topic, "ok")
+	}
 	for _, message := range messages {
 		if message.ack == nil {
 			continue
 		}
 		if err := message.ack(); err != nil {
+			addBridgeSubjectMetric(registry, "vehicle_bridge_nats_acks_total", message.subject, "error")
 			return err
 		}
+		addBridgeSubjectMetric(registry, "vehicle_bridge_nats_acks_total", message.subject, "ok")
 	}
 	return nil
 }
 
+func addBridgeSubjectMetric(registry *metrics.Registry, name string, subject string, status string) {
+	if registry == nil {
+		return
+	}
+	registry.IncCounter(name, metrics.Labels{"subject": subject, "status": status})
+}
+
+func addBridgeTopicMetric(registry *metrics.Registry, name string, topic string, status string) {
+	if registry == nil {
+		return
+	}
+	registry.IncCounter(name, metrics.Labels{"topic": topic, "status": status})
+}
+
 func kafkaMessage(topic string, data []byte) kafka.Message {
 	var env envelope.FrameEnvelope
 	message := kafka.Message{Topic: topic, Value: data}