Merge pull request #14 from yardstick/feature/QUANT-359-archimedes-integration-build-cors-compliant-web-server

QUANT-359 implement XhrListener to forward POSTs to WS

Jenkinsfile

@@ -12,12 +12,12 @@ podTemplate(label: label, inheritFrom: 'base', , containers: [
     stage('Install Dependencies') {
       container('base') {
         sh "npm install"
-        sh "npm install -g typescript"
+        sh "npm install typescript"
       }
     }
     stage('Build the Project') {
       container('base') {
-        sh "tsc"
+        sh "npx tsc"
       }
     }
     stage('Run unit tests') {
@@ -44,4 +44,4 @@ podTemplate(label: label, inheritFrom: 'base', , containers: [
       }
     }
   }
-}
+}

README.md

@@ -1,4 +1,4 @@
-# BRAID v1.2.3
+# BRAID v1.3.0
 > Websocket server for the Measure platform
 
 [![Build Status](https://semaphoreci.com/api/v1/projects/7767f0f3-4da6-4c84-9167-4db5402a3262/2573412/badge.svg)](https://semaphoreci.com/yardstick/braid)

docker_tag.txt

@@ -1 +1 @@
-1.2.3
+1.3.0

src/clients/clientBase.ts

@@ -51,7 +51,7 @@ class ClientBase {
       logger.accessLog.info(`client (${this.id}) ponged.`);
       this.ws.pong();
     }
-    this.heartbeat = setInterval(() => { this.ws.ping('ping') }, 30000);
+    //this.heartbeat = setInterval(() => { this.ws.ping('ping') }, 30000);
 
     logger.accessLog.info('Client Created', {data});
   }

src/config/app.ts

@@ -1,5 +1,5 @@
 module.exports = {
-  version : '1.2.3',
+  version : '1.3.0',
   whitelist : (process.env.WHITELIST || 'http://admin.localhost').split(','),
   secret : process.env.SECRET || 'test',
   devToken: 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJkYXRhIjp7ImNsaWVudCI6InRlc3QiLCJjbGllbnRfdHlwZSI6InNpdGUiLCJ1c2VyX3R5cGUiOiJ1c2VyIiwidXNlcl9pZCI6MjAwLCJjaGFubmVsIjoidGVzdF9jaGFubmVsIn0sImF1ZCI6ImludGVybmFsIiwiaXNzIjoiWWFyZHN0aWNrIFNvZnR3YXJlIiwic3ViIjoiQnJhaWQgSldUIn0.5KNCov_EW1cycT4Ay0oSvk4Z4PHFedd3bWOyqkHHTBQ',
@@ -15,5 +15,6 @@ module.exports = {
     audience:  'internal',
     algorithm:  ['HS256']
   },
-  messageTypes : ['broadcast', 'direct', 'changeChannel']
+  messageTypes : ['broadcast', 'direct', 'changeChannel'],
+  archimedesToken: process.env.ARCHIMEDES_INTEGRATION_TOKEN || 'testkeyformeasure'
 };

src/logger.ts

@@ -7,27 +7,42 @@ const logPath = './logs/';
 const tsFormat = () => (new Date().toISOString());
 const logFormat = format.combine(format.timestamp(), format.json());
 
-function loggerTransports(logName: string, logLevel: string) {
-  return [
-    new transports.File({
+function loggerTransports(logLevel: string, logName = "") {
+  let transport:any;
+  if ("" === logName) {
+    transport = new transports.Console({
+      format: format.simple(),
+      level: logLevel,
+      timestamp: tsFormat
+    });
+  } else {
+    transport = new transports.File({
       filename: path.join(logPath, `${logName}.log`),
       timestamp: tsFormat,
       level: logLevel
-    })
-  ];
+    });
+  }
+
+  return [ transport ];
 }
 
+const debugLog = createLogger({
+  format: format.simple(),
+  transports: loggerTransports('debug')
+});
+
 const errorLog = createLogger({
   format: logFormat,
-  transports: loggerTransports('errors', 'debug')
+  transports: loggerTransports('debug', 'errors')
 });
 
 const accessLog = createLogger({
   format: logFormat,
-  transports: loggerTransports('access', 'info')
+  transports: loggerTransports('info', 'access')
 });
 
 module.exports = {
   errorLog,
-  accessLog
+  accessLog,
+  debugLog
 };

src/server.ts

@@ -2,20 +2,29 @@
 import * as WebSocket from 'ws';
 import * as jwt from 'jsonwebtoken';
 import * as url from 'url';
+import * as express from 'express';
 
 // internal imports
 const app = require('./config/app');
 const logger = require('./logger');
+const http = require('http');
 
 import ClientManager from './clientManager';
 import ChannelManager from './channelManager';
+import XhrListener from './xhrListener';
 import PublicClient from './clients/types/publicClient';
 import PrivateClient from './clients/types/privateClient';
 import CustomClient from './clients/types/customClient';
 
-const wss = new WebSocket.Server({ maxPayload: 250000, port: app.port });
+const appExpress = express();
+const server = new http.createServer();
+// the port is no longer specified here as it induces WS to start running on its own
+// instead, we do it later in XhrListener
+const wss = new WebSocket.Server({ server: server, maxPayload: 250000 });
+
 const clientManager = new ClientManager();
 const channelManager = new ChannelManager();
+const xhrListener = new XhrListener(channelManager, server, appExpress, express.json({type: 'application/json'}));
 
 function connectionManager() {
   wss.on('connection', (ws: WebSocket, request: any, args: string) => {
@@ -63,7 +72,7 @@ function connectionManager() {
 
       channelManager.purgeEmptyChannels();
 
-      ws.send(`Hi there, welcome to braid, Measures Web Socket server. Connecting all our services!\nYou are currently in channel: ${data.channel}`);
+      ws.send(`Hi there! welcome to braid, Measures Web Socket server. Connecting all our services!\nYou are currently in channel: ${data.channel}`);
     }
   });
 }
@@ -88,5 +97,6 @@ startServer();
 module.exports = {
   clientManager,
   channelManager,
-  connectionManager
+  connectionManager,
+  xhrListener
 };

src/xhrListener.ts

@@ -0,0 +1,104 @@
+import ChannelManager from './channelManager'
+
+const logger = require('./logger');
+const url = require('url');
+const http = require('http');
+const crypto = require('crypto');
+const app = require('./config/app');
+const cors = require('cors');
+
+const AUTH_TOKEN = app.archimedesToken;
+const HTTP_PORT = app.port;
+
+import { Server, IncomingMessage, ServerResponse } from 'http'
+import * as bodyParser from "body-parser";
+interface ArchimedesMessage {
+  examId: string,
+  reservation_no: string
+}
+
+class XhrListener {
+  #cm: ChannelManager;
+
+  constructor(cm: ChannelManager, server: any, app: any, jsonParser: any) {
+
+    this.#cm = cm;
+    logger.debugLog.info("XhrListener running");
+
+    //app.use(jsonParser);
+
+    // turns out that we must compute HMAC based on the payload of the POST body, so:
+    app.use(bodyParser.json({
+      verify: ((req: any, res: any, buf: any) => { req.rawBody = buf })
+    }));
+    // TODO: try to pin down origin to reflect client rather than use wildcard
+    app.options('*', cors());
+
+    // I'm not entirely happy with bind(this) but it does let me break the
+    // callback and event handlers out into class methods. It will be
+    // problematic if the actual `this` needs to be accessed.
+
+    app.post('/event/resume', cors(),
+      (req: any, res: any, next: any) => this.eventFromArchimedes.bind(this)("resumeExam", req, res));
+    app.post('/event/pause', cors(),
+      (req: any, res: any, next: any) => this.eventFromArchimedes.bind(this)("pauseExam", req, res));
+
+
+    server.on('request', app);
+
+    // note that this kicks off HTTP listen for the entire app - not just HTTP but WS as well!
+    server.listen(HTTP_PORT, () => logger.debugLog.info(`braid is now listening for HTTP and WS connections on port ${HTTP_PORT}`));
+  }
+
+  public authorized(authOffered: String, rawBody: Buffer): boolean {
+    var hash = crypto.createHmac('sha1', AUTH_TOKEN).update(rawBody).digest("hex");
+
+    return authOffered.split("=").reverse()[0] === hash;
+  }
+
+  public eventFromArchimedes(eventType: string, req: any, res: any) {
+    logger.debugLog.info(`eventFromArchimedes("${eventType}") called`);
+    let authorized: boolean = this.authorized(req.headers['x-proctoru-signature'], req.rawBody);
+
+    if (!authorized) {
+      res.status(401);
+      res.send("Unauthorized");
+      return;
+    }
+
+    res.setHeader('Content-Type', 'application/json');
+    let amsg: ArchimedesMessage = { 'examId': req.body.examId, 'reservation_no': req.body.reservation_no };
+    if (this.relayEvent(eventType, amsg)) {
+      logger.debugLog.info('200 success relaying ' + eventType);
+      res.send(JSON.stringify(`${eventType} event was successfully relayed`));
+    } else {
+      logger.errorLog.info(`XhrListener: could not relay ${eventType} event "${amsg}" to Exam UI; body: "${req.body}"`);
+      res.status(400);
+      res.send(JSON.stringify(`error while relaying ${eventType} event`));
+    }
+  }
+
+  public relayEvent(event: string, archMsg: ArchimedesMessage): boolean {
+    logger.debugLog.info(`XhrListener:relayEvent(event: ${event}, channel: ${archMsg.reservation_no})`);
+    for (let c of this.#cm.channels) {
+      if (archMsg.reservation_no == c.id) {
+        let dmCount: number = 0;
+        for (let client of c.clients) {
+          let nonce: string = crypto.randomBytes(4).toString("hex");
+          // TODO: verify the nonce against the received reply, which we currently ignore
+          client.directMessage({
+            message_type: "broadcast",
+            message: { event_type: event, seq_id: nonce, examId: archMsg.examId }
+          });
+          dmCount++;
+        }
+        // dmCount of 1 would be normal. more than 1 is odd, but not necessarily bad. 0 means Exam UI has gone away somehow.
+        return dmCount > 0;
+      }
+    }
+    // did not match a channel; examId isn't valid for some reason
+    return false;
+  }
+}
+
+export default XhrListener;