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Mahmudur Rahman
Mahmudur Rahman

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express-insights: Your All-in-One Express Health Monitoring Middleware!

#express #monitoring #npm #node

Hey developers! 👋 Tired of cobbling together tools for backend health monitoring? Meet express-insights, a production-ready Express middleware that bundles everything you need—system metrics, service checks, authentication, rate limiting, and a sleek HTML dashboard—all in one package! Powered by express, check-disk-space, dotenv, sanitize-html, validator, and winston, it’s your go-to solution for keeping tabs on your Node.js backend or integrating into an admin panel.

📅 Released: July 12, 2025

📦 npm: npm install express-insights

🌐 npm: NPM Package

📜 License: MIT

Why express-insights?

  • All-in-One: Combines express for routing, check-disk-space for disk stats, dotenv for env config, sanitize-html for secure HTML output, validator for input validation, and winston for robust logging.
  • Flexible Output: Get JSON for APIs or a responsive HTML dashboard for admin panels.
  • Smart Monitoring: Tracks CPU, memory, disk, and network with customizable alerts.
  • Secure: Supports authentication, rate limiting, and CORS.
  • Prometheus-Ready: Expose metrics for DevOps pipelines.
  • Plug-and-Play: Minimal setup for backend or admin panel integration.

Getting Started

Installation

Install the package and its dependencies in one go:

npm install express-insights
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This pulls in express, check-disk-space, dotenv, sanitize-html, validator, and winston, so you’re ready to roll!

Basic Setup

Add the middleware to your Express app:

const express = require('express');
const { healthCheck } = require('express-insights');

const app = express();

healthCheck(app, {
  route: '/health', // Endpoint
  htmlResponse: true, // Enable HTML dashboard
  style: 'dark', // Light or dark theme
  message: 'API Health Dashboard', // Custom title
  includeDisk: true, // Disk usage stats
  includeNetwork: true, // Network interface stats
  authentication: 'my-secret-key', // Secure the endpoint
  enableMetrics: true, // Prometheus metrics
  log: {
    level: 'info',
    destination: 'console',
  },
});

app.listen(3000, () => console.log('Server running on http://localhost:3000'));
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Visit http://localhost:3000/health for JSON output or http://localhost:3000/health?html=true for the HTML dashboard (use Authorization: my-secret-key header).

Use Cases

1. Backend Health Monitoring

Monitor your server’s health directly via the /health endpoint. Get JSON output with system stats, service status, and metrics:

curl http://localhost:3000/health -H "Authorization: my-secret-key"
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Sample JSON Response:

{
  "status": "healthy",
  "uptime": "2d 1h 22m 17s",
  "version": "1.0.0",
  "environment": "production",
  "memory": {
    "heapUsed": "90 MB",
    "heapUsedPercent": "75.00%",
    "rss": "130 MB"
  },
  "system": {
    "platform": "linux",
    "memory": {
      "usedPercent": "75.00%",
      "alert": null
    },
    "loadavg": {
      "1min": "0.40",
      "alert": null
    }
  },
  "disk": {
    "total": "2000 MB",
    "used": "1200 MB",
    "free": "800 MB"
  }
}
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Use /health/metrics/prometheus for Prometheus-compatible metrics:

curl http://localhost:3000/health/metrics/prometheus
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Sample Prometheus Output:

# HELP health_check_requests_total Total health check requests
# TYPE health_check_requests_total counter
health_check_requests_total 18
# HELP health_check_response_time_ms Average response time in ms
# TYPE health_check_response_time_ms gauge
health_check_response_time_ms 134.25
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2. Admin Panel Integration

Integrate the health check into an admin panel with the HTML dashboard or fetch JSON data for custom UIs.

HTML Dashboard

Enable htmlResponse: true and visit /health or /health?html=true to see a responsive dashboard with system stats, service checks, and a raw JSON view. It’s perfect for quick status checks in an admin panel.

React Admin Panel

Fetch health data in a React app for a custom admin UI:

import { useEffect, useState } from 'react';

const HealthDashboard = () => {
  const [health, setHealth] = useState(null);

  useEffect(() => {
    fetch('http://localhost:3000/health', {
      headers: { Authorization: 'my-secret-key' },
    })
      .then((res) => res.json())
      .then((data) => setHealth(data))
      .catch((err) => console.error('Health check failed:', err));
  }, []);

  if (!health) return <p>Loading...</p>;

  return (
    <div style={{ padding: '20px', fontFamily: 'Arial' }}>
      <h2>🚦 API Health Dashboard</h2>
      <p><strong>Status:</strong> {health.status}</p>
      <p><strong>Uptime:</strong> {health.uptime}</p>
      <p><strong>Memory:</strong> {health.memory.heapUsed} ({health.memory.heapUsedPercent})</p>
      <p><strong>CPU Load (1min):</strong> {health.system?.loadavg?.['1min']}</p>
      {health.disk && (
        <p><strong>Disk Usage:</strong> {health.disk.used} / {health.disk.total}</p>
      )}
    </div>
  );
};

export default HealthDashboard;
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Plain HTML + JS

For a lightweight admin panel, use plain JavaScript:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Health Dashboard</title>
</head>
<body>
  <h2>🚦 API Health</h2>
  <pre id="output">Loading...</pre>
  <script>
    fetch('http://localhost:3000/health', {
      headers: { Authorization: 'my-secret-key' },
    })
      .then(res => res.json())
      .then(data => {
        document.getElementById('output').textContent = JSON.stringify(data, null, 2);
      })
      .catch(err => {
        document.getElementById('output').textContent = 'Error: ' + err.message;
      });
  </script>
</body>
</html>
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Custom Service Checks

Monitor databases, Redis, or external APIs with custom checks:

const dbCheck = {
  name: 'database',
  timeout: 2000,
  retries: 2,
  check: async () => {
    const isAlive = await db.ping(); // Replace with your DB logic
    if (!isAlive) throw new Error('Database down');
    return true;
  },
};

healthCheck(app, {
  route: '/health',
  customChecks: [dbCheck],
});
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Failed checks mark services as unhealthy, affecting the overall status (degraded or unhealthy).

Secure and Scalable

  • Authentication: Secure with a static key or custom logic:

    authentication: (token) => token === 'Bearer secure123'

  • Rate Limiting: Prevent abuse:

    rateLimit: { windowMs: 10000, max: 5 } // 5 requests per 10s per IP

  • CORS: Restrict access to specific origins:

    cors: { allowedOrigins: ['https://admin.myapp.com'] }

    Or use environment variables:

    export ALLOWED_ORIGINS=https://admin.myapp.com,https://myapp.com

Try It Out!

  1. Install: npm install express-insights
  2. Set up the middleware with your desired config.
  3. Access /health for JSON or HTML output.
  4. Integrate into your admin panel or monitoring pipeline.
  5. Check Prometheus metrics at /health/metrics/prometheus.

express-insights - npm

Production-ready Express middleware for backend health monitoring with metrics, HTML/JSON output, authentication, and service checks.. Latest version: 1.0.0, last published: 2 minutes ago. Start using express-insights in your project by running `npm i express-insights`. There are no other projects in the npm registry using express-insights.

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Happy monitoring! 🚀

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