index.html

<!DOCTYPE html>
<html>
<head>
	<meta charset='utf-8'/>
	<title>OSM2VectorTiles with Bright style</title>
	<meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no'/>
	<script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.18.0/mapbox-gl.js'></script>
	<link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.18.0/mapbox-gl.css' rel='stylesheet'/>
	<style>
		body{margin:0; padding:0;}
		#map{position:absolute; top:0; bottom:0; width:100%;}
	</style>
</head>
<body>
	<div id='map'></div>
	<script>
        var map = new mapboxgl.Map({
            container: 'map', // container id
            style: 'http://osmserver3.westeurope.cloudapp.azure.com:8080/styles/bright.json',
            center: [13.744, 41.816], // starting position
            zoom: 5, // starting zoom
            hash: true
        });
        map.addControl(new mapboxgl.Navigation({position: 'top-left'}));
        map.addControl(new mapboxgl.Geolocate({position: 'top-right'}));
        // Creo il GeoJSONSource [1]
        var sourceParks = new mapboxgl.GeoJSONSource({
            data : "http://osmserver3.westeurope.cloudapp.azure.com/test.geojson"// Qua ho messo un URL, ma si può inserire anche l'oggetto direttamente
        });

        map.on("load", function () {
            // Aggiungo il GeoJSONSource alla mappa [2]
            map.addSource('parchi', sourceParks);
            // Aggiungo il layer collegato al GeoJSONSource [3]
            map.addLayer({
                id:"parks",
                source:"parchi",
                type:"fill",
                paint:{
                    "fill-opacity": 0.3,
                    "fill-color": "green",
                }
            }, "water");
        });
	</script>
</body>
</html>