feat(go): expose runtime ingest metrics

go/vehicle-gateway/cmd/stat-writer/main.go

@@ -15,6 +15,7 @@ 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"
 	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/stats"
 )
@@ -35,9 +36,10 @@ func main() {
 		logger.Error("mysql ping failed", "error", err)
 		os.Exit(1)
 	}
+	registry := metrics.NewRegistry()
 	health.Start(ctx, logger, health.NewServer(env("HEALTH_ADDR", ""), "vehicle-stat-writer", []health.Check{
 		{Name: "mysql", Check: db.PingContext},
-	}))
+	}, registry))
 
 	writer := stats.NewWriter(db, cfg.Location)
 	if cfg.EnsureSchema {
@@ -66,7 +68,7 @@ func main() {
 			logger.Error("kafka fetch failed", "error", err)
 			continue
 		}
-		processStatMessage(ctx, logger, writer, reader, message)
+		processStatMessage(ctx, logger, registry, writer, reader, message)
 	}
 }
 
@@ -83,23 +85,37 @@ type kafkaMessageCommitter interface {
 func processStatMessage(ctx context.Context, logger interface {
 	Error(string, ...any)
 	Warn(string, ...any)
-}, appender statAppender, committer kafkaMessageCommitter, message kafka.Message) {
+}, registry *metrics.Registry, appender statAppender, committer kafkaMessageCommitter, message kafka.Message) {
 	messageCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), kafkaMessageOperationTimeout)
 	defer cancel()
 
+	addStatMetric(registry, "vehicle_stat_kafka_messages_total", message, "received")
 	var env envelope.FrameEnvelope
 	if err := json.Unmarshal(message.Value, &env); err != nil {
+		addStatMetric(registry, "vehicle_stat_kafka_messages_total", message, "invalid_json")
 		logger.Warn("skip invalid envelope json", "topic", message.Topic, "partition", message.Partition, "offset", message.Offset, "error", err)
 		_ = committer.CommitMessages(messageCtx, message)
 		return
 	}
 	if err := appender.Append(messageCtx, env); err != nil {
+		addStatMetric(registry, "vehicle_stat_writes_total", message, "error")
 		logger.Error("mysql append failed", "topic", message.Topic, "partition", message.Partition, "offset", message.Offset, "event_id", env.StableEventID(), "error", err)
 		return
 	}
+	addStatMetric(registry, "vehicle_stat_writes_total", message, "ok")
 	if err := committer.CommitMessages(messageCtx, message); err != nil {
+		addStatMetric(registry, "vehicle_stat_kafka_commits_total", message, "error")
 		logger.Error("kafka commit failed", "topic", message.Topic, "partition", message.Partition, "offset", message.Offset, "error", err)
+		return
 	}
+	addStatMetric(registry, "vehicle_stat_kafka_commits_total", message, "ok")
+}
+
+func addStatMetric(registry *metrics.Registry, name string, message kafka.Message, status string) {
+	if registry == nil {
+		return
+	}
+	registry.IncCounter(name, metrics.Labels{"topic": message.Topic, "status": status})
 }
 
 type config struct {

go/vehicle-gateway/cmd/stat-writer/main_test.go

@@ -3,11 +3,13 @@ package main
 import (
 	"context"
 	"encoding/json"
+	"strings"
 	"testing"
 
 	"github.com/segmentio/kafka-go"
 
 	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/metrics"
 )
 
 func TestProcessStatMessageUsesUncancelledContextForAppendAndCommit(t *testing.T) {
@@ -29,7 +31,7 @@ func TestProcessStatMessageUsesUncancelledContextForAppendAndCommit(t *testing.T
 	appender := &contextCheckingStatAppender{}
 	committer := &contextCheckingStatCommitter{}
 
-	processStatMessage(parent, discardStatLogger{}, appender, committer, kafka.Message{Value: payload})
+	processStatMessage(parent, discardStatLogger{}, nil, appender, committer, kafka.Message{Value: payload})
 
 	if appender.ctxErr != nil {
 		t.Fatalf("appender saw cancelled context: %v", appender.ctxErr)
@@ -42,6 +44,35 @@ func TestProcessStatMessageUsesUncancelledContextForAppendAndCommit(t *testing.T
 	}
 }
 
+func TestProcessStatMessageRecordsMetrics(t *testing.T) {
+	env := envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808, Phone: "13307795425", MessageID: "0x0200"}
+	payload, err := json.Marshal(env)
+	if err != nil {
+		t.Fatal(err)
+	}
+	registry := metrics.NewRegistry()
+
+	processStatMessage(
+		context.Background(),
+		discardStatLogger{},
+		registry,
+		&contextCheckingStatAppender{},
+		&contextCheckingStatCommitter{},
+		kafka.Message{Topic: "vehicle.raw.jt808.v1", Value: payload},
+	)
+
+	text := registry.Render()
+	for _, want := range []string{
+		`vehicle_stat_kafka_messages_total{status="received",topic="vehicle.raw.jt808.v1"} 1`,
+		`vehicle_stat_writes_total{status="ok",topic="vehicle.raw.jt808.v1"} 1`,
+		`vehicle_stat_kafka_commits_total{status="ok",topic="vehicle.raw.jt808.v1"} 1`,
+	} {
+		if !strings.Contains(text, want) {
+			t.Fatalf("metrics missing %s:\n%s", want, text)
+		}
+	}
+}
+
 type contextCheckingStatAppender struct {
 	ctxErr error
 	count  int