鏈路追蹤

go get github.com/aliyun/fc-runtime-go-sdk
go get go get go.opentelemetry.io/otel
go get go.opentelemetry.io/otel/sdk
go get go.opentelemetry.io/otel/exporters/jaeger

func HandleRequest(ctx context.Context, event MyEvent) (string, error) {
    // 擷取Function Compute上下文Tracing資訊
    fctx, ok := fccontext.FromContext(ctx)
    if !ok {
        return "", fmt.Errorf("failed to get FcContext")
    }
    spanCtx, endpoint, err := getFcTracingInfo(fctx)
    if err != nil {
        return "", fmt.Errorf("failed to getFcTracingInfo, error: %v", err)
    }
    // 建立Tracer Provider
    tp, err := NewTracerProvider(endpoint)
    if err != nil {
        return "", fmt.Errorf("OpenTracingJaegerEndpoint: %s, error: %v", fctx.Tracing.JaegerEndpoint, err)
    }
    // 設定為全域
    otel.SetTracerProvider(tp)
    if err != nil {
        return "", fmt.Errorf("failed to getFcSpanCtx, error: %v", err)
    }
    // 建立自訂Span
    startMySpan(trace.ContextWithSpanContext(ctx, spanCtx))
    return fmt.Sprintf("hello world! 你好，%s!", event.Name), nil
}

func tracerProvider(url string) (*tracesdk.TracerProvider, error) {
    // 建立Jaeger exporter
    exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(url)))
    if err != nil {
        return nil, err
    }
    tp := tracesdk.NewTracerProvider(
        // 註冊exporter
        tracesdk.WithBatcher(exp),
        // 在Resource裡記錄應用資訊
        tracesdk.WithResource(resource.NewWithAttributes(
            semconv.SchemaURL,
            semconv.ServiceNameKey.String("FCTracer"),
            attribute.String("environment", "production"),
            attribute.Int64("ID", 1),
        )),
    )
    return tp, nil
}

func getFcTracingInfo(fctx *fccontext.FcContext) (trace.SpanContext, string, error) {
    // 擷取Tracing資訊
    spanContext := trace.SpanContext{}
    endpoint := fctx.Tracing.JaegerEndpoint
    OpenTracingSpanContext := fctx.Tracing.OpenTracingSpanContext
    if len(endpoint) == 0 {
        return spanContext, endpoint, fmt.Errorf("invalid jaeger endpoint")
    }
    spanContextSlice := strings.Split(OpenTracingSpanContext, ":")

    // 填充TracingID高位
    tid, err := trace.TraceIDFromHex("0000000000000000" + spanContextSlice[0])
    if err != nil {
        return spanContext, endpoint, err
    }
    fid := trace.FlagsSampled
    spanContext = spanContext.WithTraceID(tid).WithTraceFlags(fid).WithRemote(true)
    return spanContext, endpoint, nil
}

func startMySpan(ctx context.Context) {
    // 使用全域TracerProvider.
    tr := otel.Tracer("fc-Trace")
    ctx, parentSpan := tr.Start(ctx, "fc-operation")
    defer parentSpan.End()
    parentSpan.SetAttributes(attribute.Key("version").String("fc-v1"))
    time.Sleep(150 * time.Millisecond)
    child(ctx)
}

func child(ctx context.Context) {
    tr := otel.Tracer("fc-Trace")
    _, childSpan := tr.Start(ctx, "fc-operation-child")
    defer childSpan.End()
    time.Sleep(100 * time.Millisecond)
    childSpan.AddEvent("timeout")
}

go get github.com/aliyun/fc-runtime-go-sdk
go get github.com/opentracing/opentracing-go
go get github.com/uber/jaeger-client-go

func HandleRequest(ctx context.Context, event MyEvent) (string, error) {
    // 擷取Function Compute上下文Tracing資訊
    fctx, _ := fccontext.FromContext(ctx)
    endpoint := fctx.Tracing.JaegerEndpoint
    OpenTracingSpanContext := fctx.Tracing.OpenTracingSpanContext
    if len(endpoint) == 0 {
        return "", fmt.Errorf("invalid jaeger endpoint")
    }
    // 建立Tracer
    tracer, closer := NewJaegerTracer("FCTracer", endpoint)
    defer closer.Close()
    // 恢複spanContext
    spanContext, err := jaeger.ContextFromString(OpenTracingSpanContext)
    if err != nil {
        return "", fmt.Errorf("OpenTracingSpanContext: %s, error: %v", fctx.Tracing.OpenTracingSpanContext, err)
    }
    // 建立自訂Span
    startMySpan(spanContext, tracer)
    return fmt.Sprintf("hello world! 你好，%s!", event.Name), nil
}

func NewJaegerTracer(service, endpoint string) (opentracing.Tracer, io.Closer) {
    sender := transport.NewHTTPTransport(endpoint)
    tracer, closer := jaeger.NewTracer(service,
        jaeger.NewConstSampler(true),
        jaeger.NewRemoteReporter(sender))
    return tracer, closer
}

func startMySpan(context jaeger.SpanContext, tracer opentracing.Tracer) {
    parentSpan := tracer.StartSpan("MyFCSpan", opentracing.ChildOf(context))
    defer parentSpan.Finish()
    parentSpan.SetOperationName("fc-operation")
    parentSpan.SetTag("version", "fc-v1")
    time.Sleep(150 * time.Millisecond)
    // 開啟子Span
    childSpan := tracer.StartSpan("fc-operation-child", opentracing.ChildOf(parentSpan.Context()))
    defer childSpan.Finish()
    time.Sleep(100 * time.Millisecond)
    childSpan.LogFields(
        log.String("type", "cache timeout"),
        log.Int("waited.millis", 100))
}