Add a nice 403 page

uitwww/__init__.py

@@ -67,6 +67,10 @@ def create_app(data_path):
     nav.add_generator("download-distros", app.download.generate_navbar)
     nav.install(app)
 
+    @app.errorhandler(403)
+    def forbidden(error):
+        return flask.render_template("403.html"), 403
+
     @app.errorhandler(404)
     def not_found(error):
         return flask.render_template("404.html"), 404

uitwww/templates/403.html

+{# Source code of the Ubuntu-it website
+ # Copyright (C) 2018  Pietro Albini <pietroalbini@ubuntu.com>
+ #
+ # This program is free software: you can redistribute it and/or modify
+ # it under the terms of the GNU Affero General Public License as published
+ # by the Free Software Foundation, either version 3 of the License, or
+ # (at your option) any later version.
+ #
+ # This program is distributed in the hope that it will be useful,
+ # but WITHOUT ANY WARRANTY; witout even the implied warranty of
+ # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ # GNU Affero General Public License for more details.
+ #
+ # You should have received a copy of the GNU Affero General Public License
+ # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ #}
+
+{% extends "layout.html" %}
+
+{% block title %}Accesso negato{% endblock %}
+
+{% block content %}
+    <div class="page">
+        <div class="row">
+            <div class="col">
+                <h1>Accesso negato</h1>
+                {% if g.auth_id %}
+                <p>
+                    Il tuo gruppo non dispone dei permessi necessari per
+                    visualizzare questa pagina.
+                </p>
+                {% else %}
+                <p>
+                    Questa pagina è riservata ai membri di Ubuntu-it con
+                    adeguati permessi. <a href="{{ url_for("auth.login") }}">
+                    Effettua l'accesso</a> per visualizzarla.
+                </p>
+                {% endif %}
+            </div>
+        </div>
+    </div>
+{% endblock %}