Agent-Native/runtime/telemetry/telemetry.go

// Package telemetry 记录 GenAI span。默认不采集提示词正文。
package telemetry

import (
	"bytes"
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"net/http"
	"os"
	"strings"
	"time"

	"logging-system/logsys"
)

// Span 是一次 invoke_agent、chat 或 execute_tool。
type Span struct {
	Name    string
	TraceID string
	SpanID  string
	Start   time.Time
	End     time.Time
	Attrs   map[string]string
}

// StartFunc 返回循环使用的追踪函数。设置了 OTEL_EXPORTER_OTLP_ENDPOINT 时，
// 结束 span 后以 OTLP/HTTP JSON 上报，不引入新的依赖。
func StartFunc(log *logsys.Logger) func(name string, attrs map[string]string) func() {
	endpoint := strings.TrimRight(os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT"), "/")
	return func(name string, attrs map[string]string) func() {
		sp := Span{
			Name: name, TraceID: newID(16), SpanID: newID(8),
			Start: time.Now(), Attrs: publicAttrs(attrs),
		}
		return func() {
			sp.End = time.Now()
			if log != nil {
				kvs := []any{"span", sp.Name, "trace_id", sp.TraceID, "span_id", sp.SpanID}
				for k, v := range sp.Attrs {
					kvs = append(kvs, k, v)
				}
				log.Info("genai span", kvs...)
			}
			if endpoint != "" {
				_ = ExportOTLP(endpoint, sp)
			}
		}
	}
}

// publicAttrs 丢掉提示词正文。调用方即使传入也不会进入 span。
func publicAttrs(in map[string]string) map[string]string {
	out := map[string]string{}
	for k, v := range in {
		if k == "prompt" || k == "messages" || k == "content" {
			continue
		}
		out[k] = v
	}
	return out
}

// ExportOTLP 把一个 span POST 到端点的 /v1/traces。
func ExportOTLP(endpoint string, sp Span) error {
	endpoint = strings.TrimRight(endpoint, "/")
	if !strings.HasSuffix(endpoint, "/v1/traces") {
		endpoint += "/v1/traces"
	}
	body, err := json.Marshal(otlpBody(sp))
	if err != nil {
		return err
	}
	req, err := http.NewRequest(http.MethodPost, endpoint, bytes.NewReader(body))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	return nil
}

func otlpBody(sp Span) map[string]any {
	var attrs []map[string]any
	for k, v := range publicAttrs(sp.Attrs) {
		attrs = append(attrs, map[string]any{"key": k, "value": map[string]any{"stringValue": v}})
	}
	return map[string]any{
		"resourceSpans": []any{map[string]any{
			"scopeSpans": []any{map[string]any{
				"spans": []any{map[string]any{
					"traceId":           sp.TraceID,
					"spanId":            sp.SpanID,
					"name":              sp.Name,
					"startTimeUnixNano": sp.Start.UnixNano(),
					"endTimeUnixNano":   sp.End.UnixNano(),
					"attributes":        attrs,
				}},
			}},
		}},
	}
}

func newID(n int) string {
	b := make([]byte, n)
	_, _ = rand.Read(b)
	return hex.EncodeToString(b)
}