AWS-Serverless-Express 如何获取先前的路由

Posted 2023-03-28

【中文标题】AWS-Serverless-Express 如何获取先前的路由

【英文标题】：AWS-Serverless-Express How To Get Previous Route

【发布时间】：2020-09-14 18:09:29

【问题描述】：

我的前端有一个导出按钮，单击该按钮时，会在我们的 Express 服务器上发送一个 POST 以记录按钮单击。这使用路由 app.post(usagereport) 。我想要做的是捕获用户单击导出时所处的路线。但是，由于发送 POST 请求的代码是它自己的路由，因此它只会在尝试类似req.route 时返回该路由的名称。

我正在使用 API Gateway + Lambda + AWS-Serverless-Express。

我在想我可以在 req.session 中存储req.session.previousRoute 之类的内容，以捕获用户加载的最后一条路由，然后将其返回给访问日志代码。但是，我不确定这种方法是否适用于 Lambda，或者是否有更好的方法来处理它。

这是我的 server.js（精简版）

// create the server and setup routes
const app = express();
const mysql = require("mysql");

// AWS-Serverless-Express https://github.com/awslabs/aws-serverless-express
const awsServerlessExpressMiddleware = require("aws-serverless-express/middleware");
app.use(awsServerlessExpressMiddleware.eventContext());

//Setup paths to database connection pools
const nawfprojectsDB = require("../lib/naWfProjectsDb.js");
const queries = require("./queries.js");
const accessLog = require("../lib/accessLog.js");

//Setup a timestamp for logging
const timestamp = new Date().toString();

// S3 Data Mitigation is needed when a data set exceeds 5 MB in size.
// This is a restriction of Lambda itself (they say 6 MB but want to ensure we dont ever hit the limit)
const s3DataMitigation = require("../lib/s3DataMitigation.js");

let environment = process.env.NODE_ENV;

app.get("/wg_data", (req, res, callback) => 
  const dataSet = "wg_data";
  nawfprojectsDB.query(queries.wg_data, (err, result) => 
    if (err) 
      console.log(err);
    
    s3Data(dataSet, res, callback, result);
    console.log(
      timestamp,
      "Returned " + result.length + " rows from  " + dataSet
    );
  );
  accessLog( dataSet, req );
);

// Usage report everytime export button is clicked
app.post("/usagereport", (req) => 
  const currentPath = dataSet;
  const dataSet = "Data Exported: " + currentPath;
  console.log(timestamp, "Data exported");
  accessLog( dataSet, req );
);


module.exports = app;

accessLog.js

let nawfprojectsDB = require("./naWfProjectsDb.js");
let queries = require("../routes/queries.js");
let environment = process.env.NODE_ENV;

//Insert data into access_logs table when usageLog is called
const accessLog = ( dataSet, req ) => 
  // We only want to log access when in beta, gamma, or prod. Not in development.
  if (environment === "development") 
    console.log("No access log as we are in dev");
   else 
    // req.apiGateway comes from AWS-Serverless-Express - https://github.com/awslabs/aws-serverless-express
    const user = req.apiGateway.event.requestContext.authorizer.principalId;
    let sqlData = [dataSet, user, environment];
    // Run the log_access query using the sqlData above
    nawfprojectsDB.query(queries.log_access, sqlData, (err) => 
      if (err) 
        console.error("MySQL query error: " + err);
      
      console.log("Access log added for: ", user, " at data set: ", dataSet);
    );
  
;

module.exports = accessLog;

【参考方案1】：

解决了我自己的问题。

解决这个问题的方法是使用 express-session。我在每条路线中都设置了req.session.previousRoute。然后我可以在我的usagereport 路由中访问它。

const  v4: uuidv4  = require("uuid");
const express = require("express");
const cookieParser = require("cookie-parser");
const session = require("express-session");
const randomString = uuidv4();
let sessionOptions = 
  cookie: 
    secret: randomString,
    maxAge: 269999999999,
  ,
  saveUninitialized: true,
  resave: true,
;
// create the server and setup routes
const app = express();

// Add express-session Middleware - https://www.npmjs.com/package/express-session
app.use(cookieParser(randomString)); // Need cookieParser to properly parse our random string into the type of value expected by session
app.use(session(sessionOptions));

// AWS-Serverless-Express - https://github.com/awslabs/aws-serverless-express
const awsServerlessExpressMiddleware = require("aws-serverless-express/middleware");
app.use(awsServerlessExpressMiddleware.eventContext());

app.get("/wg_data", (req, res, callback) => 
  const dataSet = "wg_data";
  const action = "Accessed";
  req.session.previousRoute = dataSet; // This is where we set the previousRoute in session
  nawfprojectsDB.query(queries.wg_data, (err, result) => 
    if (err) 
      console.log(err);
    
    s3Data(dataSet, res, callback, result);
    console.log(
      timestamp,
      "Returned " + result.length + " rows from  " + dataSet
    );
  );
  accessLog( dataSet, action, req );
);

// Usage report everytime export button is clicked
app.post("/usagereport", (req) => 
  // Here we grab the previousRoute set in session to see the true place the data was exported from
  const action = "Exported";
  const previousRoute = req.session.previousRoute; // Now when usagereport is triggered, it knows the previous route from the session and uses that here.
  const dataSet = previousRoute;
  console.log(timestamp, "Data exported from ", previousRoute);
  accessLog( dataSet, action, req );
);