Add tooltip to a visualization

<!DOCTYPE html>
<html>
  <head>
    <title>Create tooltip · CartoDB.js</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <link rel="shortcut icon" href="https://cartodb.com/assets/favicon.ico" />
    <style>
      html, body, #map {
        height: 100%;
        padding: 0;
        margin: 0;
      }
      /* end */
    </style>
 
    <link rel="stylesheet" href="https://libs.cartocdn.com/cartodb.js/v3/3.14/themes/css/cartodb.css" />
  </head>
  <body>
    <div id="map"></div>
 
    
    <script src="https://libs.cartocdn.com/cartodb.js/v3/3.14/cartodb.js"></script>

var url = 'https://documentation.cartodb.com/api/v2/viz/2b13c956-e7c1-11e2-806b-5404a6a683d5/viz.json';

cartodb.createVis('map', url, {
          search: true,
          tiles_loader: true,
          layer_selector: true,
          https: true
        })
        .done(function(vis, layers) {

var lyr = layers[1].getSubLayer(0);

var tooltip = vis.addOverlay({
            layer: lyr,
            type: 'tooltip',
            template: '<p>{{cartodb_id}}</p>' // mustache template
          });

})
        .error(function(err) {
          console.log(err);
        });
      }
 
      window.onload = main;
      // end
    </script>
  </body>
</html>

Modified http://libs.cartocdn.com/cartodb.js/v3/3.14/cartodb.js to a secure url

https://libs.cartocdn.com/cartodb.js/v3/3.14/cartodb.js