Push the rest

backend/analytics/cmd/server/main.go

@@ -0,0 +1,154 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"otel-bi-analytics/internal/config"
+	"otel-bi-analytics/internal/db"
+	"otel-bi-analytics/internal/handler"
+	"otel-bi-analytics/internal/scheduler"
+
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+	"go.opentelemetry.io/otel/propagation"
+	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
+)
+
+func main() {
+	slog.SetDefault(slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	})))
+
+	cfg := config.Load()
+	ctx := context.Background()
+
+	shutdown, err := setupOtel(ctx, cfg)
+	if err != nil {
+		slog.Error("failed to set up OTel", "err", err)
+		os.Exit(1)
+	}
+
+	awDB, err := db.Open(ctx, cfg.AWConnStr, "aw")
+	if err != nil {
+		slog.Error("failed to connect to AW MSSQL", "err", err)
+		os.Exit(1)
+	}
+	defer awDB.Close()
+
+	wwiDB, err := db.Open(ctx, cfg.WWIConnStr, "wwi")
+	if err != nil {
+		slog.Error("failed to connect to WWI MSSQL", "err", err)
+		os.Exit(1)
+	}
+	defer wwiDB.Close()
+
+	pgPool, err := db.OpenPostgres(ctx, cfg.PostgresDSN)
+	if err != nil {
+		slog.Error("failed to connect to PostgreSQL", "err", err)
+		os.Exit(1)
+	}
+	defer pgPool.Close()
+
+	sched := scheduler.New(awDB, wwiDB, pgPool, cfg.DefaultTopN)
+	sched.Start()
+	defer sched.Stop()
+
+	mux := http.NewServeMux()
+	h := handler.New(awDB, wwiDB, pgPool, sched, cfg.DefaultTopN, cfg.ForecastHorizonDays, cfg.DefaultHistoryDays)
+	h.RegisterRoutes(mux)
+
+	srv := &http.Server{
+		Addr:         fmt.Sprintf(":%d", cfg.Port),
+		Handler:      otelhttp.NewHandler(mux, "analytics-service"),
+		ReadTimeout:  60 * time.Second,
+		WriteTimeout: 120 * time.Second,
+		IdleTimeout:  120 * time.Second,
+	}
+
+	done := make(chan struct{})
+	go func() {
+		quit := make(chan os.Signal, 1)
+		signal.Notify(quit, syscall.SIGTERM, syscall.SIGINT)
+		<-quit
+		slog.Info("shutting down")
+
+		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+		defer cancel()
+		_ = srv.Shutdown(ctx)
+		shutdown(ctx)
+		close(done)
+	}()
+
+	slog.Info("analytics service started", "port", cfg.Port)
+	if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		slog.Error("server error", "err", err)
+		os.Exit(1)
+	}
+	<-done
+	slog.Info("shutdown complete")
+}
+
+func setupOtel(ctx context.Context, cfg config.Config) (func(context.Context), error) {
+	res, err := resource.New(ctx,
+		resource.WithAttributes(
+			semconv.ServiceName(cfg.OtelServiceName),
+			semconv.ServiceNamespace(cfg.OtelServiceNamespace),
+		),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("create OTel resource: %w", err)
+	}
+
+	traceExporter, err := otlptracehttp.New(ctx,
+		otlptracehttp.WithEndpointURL(cfg.OtelCollectorEndpoint+"/v1/traces"),
+		otlptracehttp.WithInsecure(),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("create OTLP trace exporter: %w", err)
+	}
+
+	tp := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(traceExporter),
+		sdktrace.WithResource(res),
+	)
+	otel.SetTracerProvider(tp)
+	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
+		propagation.TraceContext{},
+		propagation.Baggage{},
+	))
+
+	metricExporter, err := otlpmetrichttp.New(ctx,
+		otlpmetrichttp.WithEndpointURL(cfg.OtelCollectorEndpoint+"/v1/metrics"),
+		otlpmetrichttp.WithInsecure(),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("create OTLP metric exporter: %w", err)
+	}
+
+	mp := sdkmetric.NewMeterProvider(
+		sdkmetric.WithReader(sdkmetric.NewPeriodicReader(metricExporter, sdkmetric.WithInterval(15*time.Second))),
+		sdkmetric.WithResource(res),
+	)
+	otel.SetMeterProvider(mp)
+
+	return func(ctx context.Context) {
+		if err := tp.Shutdown(ctx); err != nil {
+			slog.Error("trace provider shutdown error", "err", err)
+		}
+		if err := mp.Shutdown(ctx); err != nil {
+			slog.Error("metric provider shutdown error", "err", err)
+		}
+	}, nil
+}