server.js

var express = require('express');
var jwt = require('jsonwebtoken');  //https://npmjs.org/package/node-jsonwebtoken
var expressJwt = require('express-jwt'); //https://npmjs.org/package/express-jwt

var secret = 'very very secret not any heartbleed';

var app = express();

// We are going to protect /api routes with JWT
app.use('/api', expressJwt({secret: secret}));

app.use(express.json());
app.use(express.urlencoded());
app.use('/', express.static(__dirname + '/public'));

app.use(function(err, req, res, next){
  if (err.constructor.name === 'UnauthorizedError') {
    res.send(401, 'Unauthorized');
  }
});

app.post('/authenticate', function (req, res) {
  //TODO validate req.body.username and req.body.password
  //if is invalid, return 401
  if (!(req.body.username === 'john.doe' && req.body.password === 'foobar')) {
    res.send(401, 'Wrong user or password');
    return;
  }

  var profile = {
    first_name: 'John',
    last_name: 'Doe',
    email: 'john@doe.com',
    id: 123
  };

  // We are sending the profile inside the token
  var token = jwt.sign(profile, secret, { expiresInMinutes: 60*5 });

  res.json({ token: token });
});

app.get('/api/view1', function (req, res) {
  console.log('user ' + req.user.email + ' is calling /api/view1');
  res.json({
    name: 'View1 Data, that requires authentication: Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.'
  });
});

app.get('/api/view2', function (req, res) {
  console.log('user ' + req.user.email + ' is calling /api/view2');
  res.json({
    name: 'View2 Data, that requires authentication: Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.'
  });
});

app.listen(8080, function () {
  console.log('listening on http://localhost:8080');
});