aws-xray-sdk-express

import express, { Request, Response, NextFunction } from 'express'; import * as AWSXRay from 'aws-xray-sdk-core'; import * as xrayExpress from 'aws-xray-sdk-express'; // Configure X-Ray SDK (defaults to environment variables like AWS_REGION, AWS_XRAY_DAEMON_ADDRESS) // For local testing without a daemon, you might set the logger to console and disable daemon sending. // AWSXRay.setLogger(console); // AWSXRay.setDaemonAddress('127.0.0.1:2000'); // Default const app = express(); const PORT = process.env.PORT || 3000; // 1. Initialize X-Ray: This middleware *must* be added before defining any routes to be traced. // In automatic mode, it is crucial that this is the LAST middleware added before your routes. // 'ExpressMicroservice' is the name that will appear for your service in X-Ray traces. app.use(xrayExpress.openSegment('ExpressMicroservice')); // Define your application routes app.get('/', (req: Request, res: Response) => { // In automatic mode, getSegment() retrieves the current segment from the context. const segment = AWSXRay.getSegment(); if (segment) { segment.addAnnotation('route', 'home'); segment.addMetadata('user', { id: 'test-user-123', session: 'abc' }); console.log(`Tracing home route within segment: ${segment.id}`); } else { console.warn('No X-Ray segment found for home route.'); } res.send('Hello from X-Ray Traced Express App!'); }); app.get('/data', async (req: Request, res: Response) => { const segment = AWSXRay.getSegment(); if (segment) { // Create a subsegment for an internal asynchronous operation const subsegment = segment.addNewSubsegment('fetchDataOperation'); subsegment.addAnnotation('data_type', 'user_profile'); await new Promise(resolve => setTimeout(resolve, 100)); // Simulate async work subsegment.close(); // Important to close subsegments console.log(`Tracing data route within segment: ${segment.id}`); } else { console.warn('No X-Ray segment found for data route.'); } res.json({ message: 'Data fetched successfully' }); }); // 2. Close X-Ray Segment: This middleware *must* be added after all routes to be traced. // In automatic mode, it must be the FIRST middleware added AFTER your routes (or before error handlers). app.use(xrayExpress.closeSegment()); // Optional: Error handling middleware for tracing errors app.use((err: Error, req: Request, res: Response, next: NextFunction) => { if (AWSXRay.isCurrentSegmentAvailable()) { AWSXRay.getSegment()?.addError(err); } console.error('An error occurred:', err.message); res.status(500).send('Something broke!'); }); app.listen(PORT, () => { console.log(`Server listening on port ${PORT}`); console.log('Ensure X-Ray daemon is running locally or AWS credentials/environment variables are configured for tracing.'); });