express-prom-bundle

import express from 'express'; import promBundle from 'express-prom-bundle'; const app = express(); // Configure the metrics middleware const metricsMiddleware = promBundle({ includeMethod: true, includePath: true, // IMPORTANT: only measures routes registered AFTER this middleware customLabels: { service_name: 'my-express-app' }, promClient: { collectDefaultMetrics: {} } // Collect default Node.js process metrics }); // Register the metrics middleware BEFORE your routes app.use(metricsMiddleware); // Define your application routes app.get('/', (req, res) => { res.send('Hello, Prometheus!'); }); app.get('/api/users/:id', (req, res) => { // Simulate an async operation setTimeout(() => { res.json({ id: req.params.id, name: `User ${req.params.id}` }); }, Math.random() * 200); }); app.get('/error', (req, res) => { res.status(500).send('Internal Server Error'); }); // The /metrics endpoint is automatically exposed by default // Access it at http://localhost:3000/metrics const PORT = process.env.PORT || 3000; app.listen(PORT, () => { console.log(`Express app listening on port ${PORT}`); console.log(`Metrics available at http://localhost:${PORT}/metrics`); });