gistfile1.js

var Hapi = require('hapi');
var Joi = require('joi');
var server = new Hapi.Server('127.0.0.1', 3000);

server.route({
    method: 'GET',
    path: '/{version}/something',
    handler: function (request, reply) {
        reply(request.params.version);
    },
    config: {
        validate: {
            path: {
                version: Joi.string().regex(/v[\d]+/)
            }
        }
    }
});

server.start(function () {
    console.log('Server running at:', server.info.uri);
});