Added OpenTelemetry and use structured logging

internal/telemetry/logger.go

@@ -0,0 +1,32 @@
+package telemetry
+
+import (
+	"context"
+	"log/slog"
+
+	"go.opentelemetry.io/otel/trace"
+)
+
+type TraceHandler struct {
+	slog.Handler
+}
+
+func (h *TraceHandler) Handle(ctx context.Context, r slog.Record) error {
+	spanCtx := trace.SpanContextFromContext(ctx)
+	if spanCtx.HasTraceID() {
+		r.AddAttrs(
+			slog.String("trace_id", spanCtx.TraceID().String()),
+			slog.String("span_id", spanCtx.SpanID().String()),
+		)
+	}
+
+	return h.Handler.Handle(ctx, r)
+}
+
+func (h *TraceHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+	return &TraceHandler{Handler: h.Handler.WithAttrs(attrs)}
+}
+
+func (h *TraceHandler) WithGroup(name string) slog.Handler {
+	return &TraceHandler{Handler: h.Handler.WithGroup(name)}
+}

internal/telemetry/otel.go

@@ -0,0 +1,57 @@
+package telemetry
+
+import (
+	"context"
+	"errors"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+)
+
+func Init(ctx context.Context, serviceName string, version string) (func(context.Context) error, error) {
+	var shutdownFns []func(context.Context) error
+
+	shutdown := func(ctx context.Context) error {
+		var err error
+		for _, fn := range shutdownFns {
+			err = errors.Join(err, fn(ctx))
+		}
+		shutdownFns = nil
+		return err
+	}
+
+	res, err := resource.New(ctx,
+		resource.WithAttributes(
+			semconv.ServiceName(serviceName),
+			semconv.ServiceVersion(version),
+		),
+	)
+	if err != nil {
+		return shutdown, err
+	}
+
+	otel.SetTextMapPropagator(
+		propagation.NewCompositeTextMapPropagator(
+			propagation.TraceContext{},
+			propagation.Baggage{},
+		),
+	)
+
+	traceExporter, err := otlptracegrpc.New(ctx)
+	if err != nil {
+		return shutdown, err
+	}
+
+	tracerProvider := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(traceExporter),
+		sdktrace.WithResource(res),
+	)
+	otel.SetTracerProvider(tracerProvider)
+	shutdownFns = append(shutdownFns, tracerProvider.Shutdown)
+
+	return shutdown, nil
+}