Добавлены метрики Prometheus и дашборды Grafana (этап 2.5)

Все три Go-сервиса (ingest, device-control, rule-engine) отдают
/metrics в формате Prometheus: счётчики MQTT/RabbitMQ/ClickHouse
операций, гистограммы длительности батч-флашей и диспатча правил,
переходы устройств online/offline. Добавлены сервисы prometheus и
grafana в docker-compose с провижининг конфигом (datasource +
два готовых дашборда: "Ingest & Telemetry" и "Automation & Devices").

services/ingest-service/cmd/ingest-service/main.go

@@ -5,16 +5,21 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"log/slog"
+	"net/http"
 	"os"
 	"os/signal"
 	"sync"
 	"syscall"
 	"time"
 
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+
 	"git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/batch"
 	chstore "git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/clickhouse"
 	"git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/config"
+	"git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/metrics"
 	"git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/mqttclient"
 	"git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/rabbitmq"
 	"git.cactoz.su/cacto/home_automatization/services/ingest-service/internal/telemetry"
@@ -59,7 +64,7 @@ func run(logger *slog.Logger) error {
 	}
 	defer publisher.Close()
 
-	batcher := batch.New(cfg.BatchMaxSize, cfg.BatchFlushInterval, cfg.BatchFlushTimeout, store.InsertBatch, logger)
+	batcher := batch.New(cfg.BatchMaxSize, cfg.BatchFlushInterval, cfg.BatchFlushTimeout, instrumentedInsert(store), logger)
 	batcher.Start()
 	defer batcher.Stop()
 
@@ -77,6 +82,9 @@ func run(logger *slog.Logger) error {
 			cancel()
 			if err != nil {
 				logger.Error("publish reading event failed", "device_id", reading.DeviceID, "error", err)
+				metrics.RabbitMQPublishes.WithLabelValues("error").Inc()
+			} else {
+				metrics.RabbitMQPublishes.WithLabelValues("success").Inc()
 			}
 		}
 	}()
@@ -87,9 +95,12 @@ func run(logger *slog.Logger) error {
 		Topic:     cfg.MQTTTopic,
 		QoS:       1,
 	}, func(payload []byte, receivedAt time.Time) {
+		metrics.MQTTMessagesReceived.Inc()
+
 		reading, err := telemetry.ParseReading(payload, receivedAt)
 		if err != nil {
 			logger.Warn("dropping invalid telemetry payload", "error", err)
+			metrics.MQTTMessagesInvalid.Inc()
 			return
 		}
 
@@ -97,12 +108,24 @@ func run(logger *slog.Logger) error {
 		case incoming <- reading:
 		default:
 			logger.Error("dropping reading: worker backlog full", "device_id", reading.DeviceID)
+			metrics.MQTTMessagesDropped.Inc()
 		}
 	}, logger)
 	if err != nil {
 		return err
 	}
 
+	metricsServer := &http.Server{
+		Addr:    fmt.Sprintf(":%d", cfg.MetricsPort),
+		Handler: promhttp.Handler(),
+	}
+	go func() {
+		logger.Info("metrics server started", "metrics_port", cfg.MetricsPort)
+		if err := metricsServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			logger.Error("metrics server stopped", "error", err)
+		}
+	}()
+
 	logger.Info("ingest-service started", "mqtt_topic", cfg.MQTTTopic)
 
 	stop := make(chan os.Signal, 1)
@@ -114,5 +137,30 @@ func run(logger *slog.Logger) error {
 	close(incoming)
 	workerWG.Wait()
 
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	if err := metricsServer.Shutdown(shutdownCtx); err != nil {
+		logger.Error("metrics server shutdown failed", "error", err)
+	}
+
 	return nil
 }
+
+// instrumentedInsert wraps store.InsertBatch with duration/size/outcome
+// metrics, without teaching the batch or clickhouse packages about Prometheus.
+func instrumentedInsert(store *chstore.Store) batch.FlushFunc {
+	return func(ctx context.Context, readings []telemetry.Reading) error {
+		start := time.Now()
+		err := store.InsertBatch(ctx, readings)
+
+		metrics.BatchFlushDuration.Observe(time.Since(start).Seconds())
+		metrics.BatchSize.Observe(float64(len(readings)))
+		if err != nil {
+			metrics.BatchFlushes.WithLabelValues("error").Inc()
+		} else {
+			metrics.BatchFlushes.WithLabelValues("success").Inc()
+		}
+
+		return err
+	}
+}