iplogger.js

iplogger.js

// ip-logger.js
// Simple IP logger using Express
// Run: node ip-logger.js
// Requires: npm install express

const express = require('express');
const fs = require('fs');
const path = require('path');

const PORT = process.env.PORT || 3000;
const LOG_FILE = path.join(__dirname, 'visitors.csv');

const app = express();

// If you're behind a proxy (nginx, cloudflare, etc), enable this so req.ip uses X-Forwarded-For
app.set('trust proxy', true);

// Ensure log file has header
if (!fs.existsSync(LOG_FILE)) {
  fs.writeFileSync(LOG_FILE, 'timestamp,ip,xff,user_agent,method,path,referer\n', { encoding: 'utf8' });
}

function getClientIp(req) {
  // Express's req.ip returns the remote address or the left-most entry in X-Forwarded-For when trust proxy is true
  return req.ip || req.connection.remoteAddress || '';
}

function appendLog(req) {
  const ts = new Date().toISOString();
  const ip = getClientIp(req).replace(/,/g, ''); // avoid commas breaking CSV
  const xff = (req.headers['x-forwarded-for'] || '').replace(/,/g, ';');
  const ua = (req.headers['user-agent'] || '').replace(/,/g, ' ');
  const method = req.method;
  const p = req.originalUrl || req.url;
  const referer = (req.headers.referer || req.headers.referrer || '').replace(/,/g, '');
  const line = `${ts},${ip},${xff},${ua},${method},${p},${referer}\n`;
  fs.appendFile(LOG_FILE, line, (err) => {
    if (err) console.error('Failed to append log:', err);
  });
  console.log(`${ts} - ${ip} - ${p} - ${ua}`);
}

// Simple middleware to log every request
app.use((req, res, next) => {
  appendLog(req);
  next();
});

// A friendly page
app.get('/', (req, res) => {
  res.type('html').send(`
    <h2>IP Logger Demo</h2>
    <p>Your visit has been logged (if this server is public-facing).</p>
    <p>To log visits from other pages/emails, embed this image as a beacon:</p>
    <pre>&lt;img src="${req.protocol}://${req.get('host')}/beacon.png" alt="" /&gt;</pre>
  `);
});

// 1x1 transparent PNG (base64) used as a beacon
const pixel = Buffer.from(
  'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR4nGNgYAAAAAMAASsJTYQAAAAASUVORK5CYII=',
  'base64'
);

app.get('/beacon.png', (req, res) => {
  // We already logged via middleware, return a tiny image
  res.set({
    'Content-Type': 'image/png',
    'Cache-Control': 'no-cache, no-store, must-revalidate',
    'Pragma': 'no-cache',
    'Expires': '0',
  });
  res.send(pixel);
});

// Optional: endpoint to download logs (protect in real use!)
app.get('/download-logs', (req, res) => {
  // WARNING: do not expose this in production without auth
  res.download(LOG_FILE, 'visitors.csv');
});

app.listen(PORT, () => {
  console.log(`IP logger running on http://localhost:${PORT} (trust proxy: ${app.get('trust proxy')})`);
  console.log(`Logs append to: ${LOG_FILE}`);
});