URL Shrinker: acortador de URLs con Node 24 + node:sqlite

App sin dependencias: UI web, POST /api/shorten (codigo aleatorio o personalizado), redireccion 302 con contador de clics, /api/stats/<code> y /healthz. SQLite en DATA_DIR (/data) para montar volumen persistente.
2026-09-12 03:38:39 +02:00
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 test-data/
 *.db
 *.db-*
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 FROM node:24-alpine
 WORKDIR /app
 COPY server.js index.html ./
 ENV NODE_ENV=production \
    PORT=3000 \
    DATA_DIR=/data
 RUN mkdir -p /data && chown node:node /data /app
 USER node
 EXPOSE 3000
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s \
  CMD wget -qO- http://127.0.0.1:3000/healthz || exit 1
 CMD ["node", "server.js"]
--- a/README.md
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 # URL Shrinker
 Acortador de URLs minimalista. Node.js 24 sin dependencias (`node:http` + `node:sqlite`),
 un solo contenedor.
 **Producción:** https://shrink.montlab.dev
 ## API
 | Método | Ruta | Qué hace |
 |---|---|---|
 | `POST` | `/api/shorten` | Body `{"url": "https://…", "code": "opcional"}` → `201 {code, url, short_url}` |
 | `GET` | `/<code>` | Redirección 302 al destino (cuenta el clic) |
 | `GET` | `/api/stats/<code>` | `{code, url, clicks, created_at, short_url}` |
 | `GET` | `/healthz` | `{ok, links, clicks}` |
 | `GET` | `/` | UI web |
 Códigos generados: 6 caracteres base58. Códigos personalizados: `[A-Za-z0-9_-]{3,32}`
 (`api` y `healthz` están reservados).
 ```bash
 curl -X POST https://shrink.montlab.dev/api/shorten \
  -H 'Content-Type: application/json' \
  -d '{"url": "https://es.wikipedia.org/wiki/Anexo:Ejemplo"}'
 ```
 ## Configuración
 | Variable | Por defecto | Descripción |
 |---|---|---|
 | `PORT` | `3000` | Puerto de escucha |
 | `DATA_DIR` | `/data` | Directorio de la base SQLite (montar volumen persistente) |
 | `BASE_URL` | `http://localhost:3000` | Base con la que se construyen los enlaces cortos |
 ## Desarrollo local
 ```bash
 DATA_DIR=./data BASE_URL=http://localhost:3000 node server.js
 ```
 Requiere Node ≥ 24 (usa `node:sqlite`).
 ## Despliegue
 Pipeline estándar de MontLab: push a este repo (Gitea) → webhook → Coolify reconstruye el
 Dockerfile y publica en `shrink.montlab.dev` (Caddy + Let's Encrypt automáticos).
 La base de datos vive en un volumen persistente montado en `/data`.
--- a/index.html
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 <!doctype html>
 <html lang="es">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>URL Shrinker</title>
 <style>
  :root {
    --bg: #0f1117; --card: #181b24; --text: #e8eaf0; --muted: #9aa1b2;
    --accent: #5b8def; --accent-hover: #7aa2f2; --error: #e06c75; --ok: #7fbf7f;
    --border: #2a2f3d; --radius: 10px;
  }
  @media (prefers-color-scheme: light) {
    :root {
      --bg: #f4f5f8; --card: #ffffff; --text: #1c1f26; --muted: #5c6270;
      --accent: #3b6fd4; --accent-hover: #2a5cbf; --error: #c0392b; --ok: #2e7d32;
      --border: #dde0e8;
    }
  }
  * { box-sizing: border-box; }
  body {
    margin: 0; min-height: 100vh; display: flex; align-items: center; justify-content: center;
    background: var(--bg); color: var(--text);
    font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; padding: 1.5rem;
  }
  main { width: 100%; max-width: 34rem; }
  h1 { font-size: 1.6rem; margin: 0 0 .25rem; }
  h1 span { color: var(--accent); }
  p.sub { color: var(--muted); margin: 0 0 1.5rem; }
  form {
    background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 1.25rem; display: grid; gap: .75rem;
  }
  label { font-size: .85rem; color: var(--muted); display: grid; gap: .3rem; }
  input {
    width: 100%; padding: .6rem .75rem; border-radius: 6px; border: 1px solid var(--border);
    background: var(--bg); color: var(--text); font-size: 1rem;
  }
  input:focus { outline: 2px solid var(--accent); outline-offset: -1px; border-color: transparent; }
  button {
    padding: .65rem; border: 0; border-radius: 6px; background: var(--accent); color: #fff;
    font-size: 1rem; font-weight: 600; cursor: pointer;
  }
  button:hover { background: var(--accent-hover); }
  button:disabled { opacity: .6; cursor: wait; }
  #result {
    margin-top: 1rem; padding: 1rem 1.25rem; border-radius: var(--radius); display: none;
    background: var(--card); border: 1px solid var(--border); word-break: break-all;
  }
  #result.ok { display: block; border-color: var(--ok); }
  #result.err { display: block; border-color: var(--error); color: var(--error); }
  #result a { color: var(--accent); font-weight: 600; text-decoration: none; font-size: 1.1rem; }
  #result a:hover { text-decoration: underline; }
  #copy {
    margin-left: .6rem; padding: .25rem .6rem; font-size: .8rem; font-weight: 500;
    background: transparent; color: var(--muted); border: 1px solid var(--border);
  }
  #copy:hover { color: var(--text); background: transparent; }
  footer { margin-top: 1.25rem; text-align: center; color: var(--muted); font-size: .8rem; }
 </style>
 </head>
 <body>
 <main>
  <h1>URL <span>Shrinker</span></h1>
  <p class="sub">Pega una URL larga, llévate una corta.</p>
  <form id="form">
    <label>URL a acortar
      <input id="url" type="url" placeholder="https://ejemplo.com/una/ruta/muy/larga" required autofocus>
    </label>
    <label>Código personalizado <small>(opcional, 3–32 caracteres)</small>
      <input id="code" type="text" pattern="[A-Za-z0-9_\-]{3,32}" placeholder="mi-enlace">
    </label>
    <button type="submit" id="submit">Acortar</button>
  </form>
  <div id="result"></div>
  <footer>montlab.dev · los enlaces cuentan sus clics: <code>/api/stats/&lt;código&gt;</code></footer>
 </main>
 <script>
 const form = document.getElementById('form');
 const result = document.getElementById('result');
 form.addEventListener('submit', async (e) => {
  e.preventDefault();
  const btn = document.getElementById('submit');
  btn.disabled = true;
  result.className = '';
  try {
    const body = { url: document.getElementById('url').value };
    const code = document.getElementById('code').value.trim();
    if (code) body.code = code;
    const res = await fetch('/api/shorten', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    });
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || 'error ' + res.status);
    result.className = 'ok';
    result.innerHTML = '';
    const a = document.createElement('a');
    a.href = data.short_url; a.textContent = data.short_url; a.target = '_blank'; a.rel = 'noopener';
    const copy = document.createElement('button');
    copy.id = 'copy'; copy.type = 'button'; copy.textContent = 'Copiar';
    copy.onclick = async () => {
      await navigator.clipboard.writeText(data.short_url);
      copy.textContent = '¡Copiado!';
      setTimeout(() => (copy.textContent = 'Copiar'), 1500);
    };
    result.append(a, copy);
  } catch (err) {
    result.className = 'err';
    result.textContent = err.message;
  } finally {
    btn.disabled = false;
  }
 });
 </script>
 </body>
 </html>
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 import { createServer } from 'node:http';
 import { DatabaseSync } from 'node:sqlite';
 import { randomBytes } from 'node:crypto';
 import { mkdirSync, readFileSync } from 'node:fs';
 import { join, dirname } from 'node:path';
 import { fileURLToPath } from 'node:url';
 const PORT = Number(process.env.PORT || 3000);
 const DATA_DIR = process.env.DATA_DIR || '/data';
 const BASE_URL = (process.env.BASE_URL || `http://localhost:${PORT}`).replace(/\/+$/, '');
 const CODE_LENGTH = 6;
 const ALPHABET = 'ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz23456789';
 mkdirSync(DATA_DIR, { recursive: true });
 const db = new DatabaseSync(join(DATA_DIR, 'shrinker.db'));
 db.exec(`
  PRAGMA journal_mode = WAL;
  CREATE TABLE IF NOT EXISTS links (
    code       TEXT PRIMARY KEY,
    url        TEXT NOT NULL,
    clicks     INTEGER NOT NULL DEFAULT 0,
    created_at TEXT NOT NULL DEFAULT (datetime('now'))
  );
 `);
 const insertLink = db.prepare('INSERT INTO links (code, url) VALUES (?, ?)');
 const getLink = db.prepare('SELECT code, url, clicks, created_at FROM links WHERE code = ?');
 const bumpClicks = db.prepare('UPDATE links SET clicks = clicks + 1 WHERE code = ?');
 const countLinks = db.prepare('SELECT COUNT(*) AS n, COALESCE(SUM(clicks), 0) AS c FROM links');
 const INDEX_HTML = readFileSync(join(dirname(fileURLToPath(import.meta.url)), 'index.html'));
 function randomCode() {
  const bytes = randomBytes(CODE_LENGTH);
  let code = '';
  for (let i = 0; i < CODE_LENGTH; i++) code += ALPHABET[bytes[i] % ALPHABET.length];
  return code;
 }
 function validTarget(raw) {
  let url;
  try {
    url = new URL(raw);
  } catch {
    return null;
  }
  if (url.protocol !== 'http:' && url.protocol !== 'https:') return null;
  return url.href;
 }
 function sendJson(res, status, body) {
  const payload = JSON.stringify(body);
  res.writeHead(status, {
    'Content-Type': 'application/json; charset=utf-8',
    'Content-Length': Buffer.byteLength(payload),
  });
  res.end(payload);
 }
 function readBody(req) {
  return new Promise((resolve, reject) => {
    const chunks = [];
    let size = 0;
    req.on('data', (chunk) => {
      size += chunk.length;
      if (size > 16384) {
        reject(new Error('body too large'));
        req.destroy();
        return;
      }
      chunks.push(chunk);
    });
    req.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
    req.on('error', reject);
  });
 }
 const server = createServer(async (req, res) => {
  const { pathname } = new URL(req.url, BASE_URL);
  if (req.method === 'GET' && pathname === '/') {
    res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });
    res.end(INDEX_HTML);
    return;
  }
  if (req.method === 'GET' && pathname === '/healthz') {
    const { n, c } = countLinks.get();
    sendJson(res, 200, { ok: true, links: n, clicks: c });
    return;
  }
  if (req.method === 'POST' && pathname === '/api/shorten') {
    let body;
    try {
      body = JSON.parse(await readBody(req) || '{}');
    } catch {
      sendJson(res, 400, { error: 'invalid JSON body' });
      return;
    }
    const url = validTarget(String(body.url ?? ''));
    if (!url) {
      sendJson(res, 400, { error: 'invalid url — must be absolute http(s)' });
      return;
    }
    let code = null;
    if (body.code !== undefined && body.code !== null && body.code !== '') {
      const custom = String(body.code);
      if (!/^[A-Za-z0-9_-]{3,32}$/.test(custom)) {
        sendJson(res, 400, { error: 'custom code must be 3-32 chars of [A-Za-z0-9_-]' });
        return;
      }
      if (custom === 'api' || custom === 'healthz') {
        sendJson(res, 400, { error: 'that code is reserved' });
        return;
      }
      try {
        insertLink.run(custom, url);
        code = custom;
      } catch {
        sendJson(res, 409, { error: 'code already taken' });
        return;
      }
    } else {
      for (let attempt = 0; attempt < 5 && code === null; attempt++) {
        const candidate = randomCode();
        try {
          insertLink.run(candidate, url);
          code = candidate;
        } catch {
          /* collision, retry */
        }
      }
      if (code === null) {
        sendJson(res, 500, { error: 'could not allocate a code, try again' });
        return;
      }
    }
    sendJson(res, 201, { code, url, short_url: `${BASE_URL}/${code}` });
    return;
  }
  if (req.method === 'GET' && pathname.startsWith('/api/stats/')) {
    const row = getLink.get(pathname.slice('/api/stats/'.length));
    if (!row) {
      sendJson(res, 404, { error: 'not found' });
      return;
    }
    sendJson(res, 200, { ...row, short_url: `${BASE_URL}/${row.code}` });
    return;
  }
  if (req.method === 'GET' && /^\/[A-Za-z0-9_-]{3,32}$/.test(pathname)) {
    const row = getLink.get(pathname.slice(1));
    if (row) {
      bumpClicks.run(row.code);
      res.writeHead(302, { Location: row.url, 'Cache-Control': 'no-store' });
      res.end();
      return;
    }
  }
  sendJson(res, 404, { error: 'not found' });
 });
 server.listen(PORT, () => {
  console.log(`url-shrinker listening on :${PORT} (base ${BASE_URL}, data ${DATA_DIR})`);
 });