avahi: Use new setup mechanism

plinth/modules/avahi/__init__.py

@@ -24,24 +24,45 @@ from django.utils.translation import ugettext_lazy as _
 from plinth import action_utils
 from plinth import cfg
 from plinth import service as service_module
+from plinth.utils import format_lazy
 
 # pylint: disable=C0103
 
+version = 1
+
+is_essential = True
+
 depends = ['system']
 
+title = _('Service Discovery')
+
+description = [
+    format_lazy(
+        _('Service discovery allows other devices on the network to '
+          'discover your {{ box_name }} and services running on it.  It '
+          'also allows {{ box_name }} to discover other devices and '
+          'services running on your local network.  Service discovery is '
+          'not essential and works only on internal networks.  It may be '
+          'disabled to improve security especially when connecting to a '
+          'hostile local network.'), box_name=_(cfg.box_name))
+]
+
 service = None
 
 
 def init():
     """Intialize the service discovery module."""
     menu = cfg.main_menu.get('system:index')
-    menu.add_urlname(_('Service Discovery'), 'glyphicon-lamp',
-                     'avahi:index', 950)
+    menu.add_urlname(title, 'glyphicon-lamp', 'avahi:index', 950)
 
     global service  # pylint: disable=W0603
     service = service_module.Service(
-        'avahi', _('Service Discovery'), ['mdns'],
-        is_external=False, enabled=is_enabled())
+        'avahi', title, ['mdns'], is_external=False, enabled=is_enabled())
+
+
+def setup(helper, old_version=False):
+    """Install and configure the module."""
+    helper.install(['avahi-daemon'])
 
 
 def is_enabled():

plinth/modules/avahi/templates/avahi.html

@@ -1,4 +1,4 @@
-{% extends "base.html" %}
+{% extends "app.html" %}
 {% comment %}
 #
 # This file is part of Plinth.
@@ -21,21 +21,7 @@
 {% load bootstrap %}
 {% load i18n %}
 
-{% block content %}
-
-  <h2>{% trans "Service Discovery" %}</h2>
-
-  <p>
-    {% blocktrans trimmed %}
-      Service discovery allows other devices on the network to
-      discover your {{ box_name }} and services running on it.  It
-      also allows {{ box_name }} to discover other devices and
-      services running on your local network.  Service discovery is
-      not essential and works only on internal networks.  It may be
-      disabled to improve security especially when connecting to a
-      hostile local network.
-    {% endblocktrans %}
-  </p>
+{% block configuration %}
 
   <h3>{% trans "Status" %}</h3>
 

plinth/modules/avahi/views.py

@@ -26,14 +26,12 @@ import logging
 
 from .forms import ServiceDiscoveryForm
 from plinth import actions
-from plinth import package
 from plinth.modules import avahi
 
 
 logger = logging.getLogger(__name__)  # pylint: disable=C0103
 
 
-@package.required(['avahi-daemon'])
 def index(request):
     """Serve configuration page."""
     status = get_status()
@@ -50,7 +48,8 @@ def index(request):
         form = ServiceDiscoveryForm(initial=status, prefix='avahi')
 
     return TemplateResponse(request, 'avahi.html',
-                            {'title': _('Service Discovery'),
+                            {'title': avahi.title,
+                             'description': avahi.description,
                              'status': status,
                              'form': form})