AWS X-Ray with Node.JS Express and request

Question

所以我正在尝试用我的快递应用程序实现X射线。我有我的应用程序.js文件，里面引用了一个路由器文件。

我的项目结构：
project/ routes/ index.js app.js

应用.js：

var indexRouter = require("./routes/index")
...
app.use("/", indexRouter)
...

索引.js：

const AWSXRay = require("aws-xray-sdk")
const request = require("request")
router.post("/xray", async function(req, res, next) {
    let app = req.app
    app.use(AWSXRay.express.openSegment("MyApp"))
    try {
        console.log(AWSXRay.getSegment()) // this succesfully gets segment
        AWSXRay.captureAsyncFunc("send", function(subsegment) {
            request.get("http://www.google.com", { XRaySegment: subsegment }, function() {
                res.json({
                    success: "success"
                })
                subsegment.close()
        })
    } catch (err) {
        next(err)
    }
    app.use(AWSXRay.express.closeSegment())
})

我正在遵循自动模式示例：通过 AWS 文档 (https://docs.aws.amazon.com/xray-sdk-for-nodejs/latest/reference/index.html( 中的异步函数调用捕获，但我收到一条错误消息："无法从上下文中获取当前子/段。"

谁能让我知道我做错了什么？

Answer 1

您应该将app.use(AWSXRay.express.openSegment("MyApp"))代码移动到app.use("/", indexRouter)上方的app.js

然后将app.use(AWSXRay.express.closeSegment())移到app.use("/", indexRouter)下方。

如果您查看提供的链接中引用的代码，您会注意到openSegment和closeSegment在路由之外，而不是在内部(因为您目前拥有它们(

链接中的代码以供参考：

var app = express();
//...
var AWSXRay = require('aws-xray-sdk');
app.use(AWSXRay.express.openSegment('defaultName'));               //required at the start of your routes
app.get('/', function (req, res) {
  res.render('index');
});
app.use(AWSXRay.express.closeSegment());   //Required at the end of your routes / first in error handling routes