platform/web/globals/otel.go

package globals

import (
	"context"
	"fmt"
	"platform/pkg/env"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"
	"go.opentelemetry.io/otel/sdk/trace"

	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
)

var tp *trace.TracerProvider

func initOtel(ctx context.Context) error {
	if env.OtelHost == "" || env.OtelPort == "" {
		return nil
	}

	addr := env.OtelHost + ":" + env.OtelPort
	exporter, err := otlptracegrpc.New(ctx,
		otlptracegrpc.WithEndpoint(addr),
		otlptracegrpc.WithInsecure(),
	)
	if err != nil {
		return fmt.Errorf("初始化 trace exporter 失败: %w", err)
	}

	tp = trace.NewTracerProvider(
		trace.WithBatcher(exporter),
		trace.WithSampler(trace.AlwaysSample()),
		trace.WithResource(
			resource.NewWithAttributes(
				semconv.SchemaURL,
				semconv.ServiceNameKey.String("lanhu-platform"),
			),
		),
	)

	otel.SetTracerProvider(tp)
	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))

	return nil
}

func closeOtel() error {
	err := tp.Shutdown(context.Background())
	if err != nil {
		return fmt.Errorf("关闭 trace provider 失败: %v", err)
	}
	return nil
}