Sistema de autenticacion con token

Ejemplo.js

// configuración postman
header: {
  x-access-token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6ImRpZWdvIiwiaWF0IjoxNTMyNDc2NDE2LCJleHAiOjE1MzI0ODAwMTZ9.Ev-x8tQPkmnA6FAYgTts0W2LwWQITmzAPy6oomKRKVc
}

index.js

const express = require('express');
const bodyParser = require('body-parser');
const jwt = require('jsonwebtoken');
const middlewareJwt = require('express-jwt');

const secret = 'keysegurytiproffesinal';
const app = express();
const middleware = middlewareJwt({ secret })

app.use(bodyParser.json());

app.post('/signin', (req, res) => {
  const { email, password } = req.body;

  if (email === 'lolo' && password === 'lolo') {
    const token = jwt.sign({ 
      id: 'diego',
    },secret, { expiresIn: '1h' });
    res.send({ token });
    return;
  }
  res.status(401).send({ error: 'bad credentials' });
});

app.post('/', (req, res) => {
  try {
    const id = validateToken(req)
    res.send( id );
  } catch ({ message }) {
    res.status(401).send({ message });
  } 
});

const validateToken = (req) => {
  var token = req.headers['x-access-token'];
  if (!token) return res.status(401).send({ auth: false, message: 'No token provided.' });
  return jwt.verify(token, secret);
}

app.get('/logout', function(req, res) {
    res.status(200).send({ auth: false, token: null });
});

app.listen(3000);