avahi: Minor fixes

- PEP8 fixes.

- Don't need to disable .socket and .service.  Disabling .service will
  take care of disabling both.

- Update the introduction message.

- Add prefix to form so that it can potentially be mixed with other
  forms.

actions/avahi

@@ -17,7 +17,7 @@
 #
 
 """
-Configuration helper for service discovery
+Configuration helper for service discovery.
 """
 
 import argparse
@@ -38,14 +38,12 @@ def parse_arguments():
 
 def subcommand_enable(_):
     """Start service."""
-    action_utils.service_enable('avahi-daemon.socket')
-    action_utils.service_enable('avahi-daemon.service')
+    action_utils.service_enable('avahi-daemon')
 
 
 def subcommand_disable(_):
     """Stop service."""
-    action_utils.service_disable('avahi-daemon.service')
-    action_utils.service_disable('avahi-daemon.socket')
+    action_utils.service_disable('avahi-daemon')
 
 
 def main():

plinth/modules/avahi/__init__.py

@@ -16,7 +16,7 @@
 #
 
 """
-Plinth module for service discovery
+Plinth module for service discovery.
 """
 
 from gettext import gettext as _
@@ -40,7 +40,7 @@ def init():
     menu.add_urlname(_('Service Discovery'), 'glyphicon-lamp',
                      'avahi:index', 950)
 
-    global service # pylint: disable=W0603
+    global service  # pylint: disable=W0603
     service = service_module.Service(
         'avahi', _('Service Discovery'), ['mdns'],
         is_external=False, enabled=is_enabled())

plinth/modules/avahi/forms.py

@@ -16,7 +16,7 @@
 #
 
 """
-Plinth module for service discovery forms
+Plinth module for service discovery forms.
 """
 
 from django import forms

plinth/modules/avahi/templates/avahi.html

@@ -24,12 +24,12 @@
 
 <h2>Service Discovery</h2>
 
-<p>Service discovery is a program that can discover other machines and services
-running on your local network. It can also helps those other machines find your
-FreedomBox, and the services running on it. Service discovery is not required,
-though. Some users decide to disable it to minimize the 
-<a href="https://en.wikipedia.org/wiki/Attack_surface">attack surface</a>
-of their FreedomBox.
+<p>Service discovery allows other machines on the network to discover
+  your FreedomBox and services running on it.  It also allows
+  FreedomBox to discover other machines 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.</p>
 
 <h3>Status</h3>
 

plinth/modules/avahi/urls.py

@@ -16,12 +16,12 @@
 #
 
 """
-URLs for the service discovery module
+URLs for the service discovery module.
 """
 
 from django.conf.urls import patterns, url
 
-urlpatterns = patterns( # pylint: disable=C0103
+urlpatterns = patterns(  # pylint: disable=C0103
     'plinth.modules.avahi.views',
     url(r'^sys/avahi/$', 'index', name='index'),
     )

plinth/modules/avahi/views.py

@@ -16,7 +16,7 @@
 #
 
 """
-Plinth module for service discovery views
+Plinth module for service discovery views.
 """
 
 from django.contrib import messages
@@ -30,7 +30,7 @@ from plinth import package
 from plinth.modules import avahi
 
 
-logger = logging.getLogger(__name__) # pylint: disable=C0103
+logger = logging.getLogger(__name__)  # pylint: disable=C0103
 
 
 @package.required(['avahi-daemon'])
@@ -41,13 +41,13 @@ def index(request):
     form = None
 
     if request.method == 'POST':
-        form = ServiceDiscoveryForm(request.POST)
+        form = ServiceDiscoveryForm(request.POST, prefix='avahi')
         if form.is_valid():
             _apply_changes(request, status, form.cleaned_data)
             status = get_status()
-            form = ServiceDiscoveryForm(initial=status)
+            form = ServiceDiscoveryForm(initial=status, prefix='avahi')
     else:
-        form = ServiceDiscoveryForm(initial=status)
+        form = ServiceDiscoveryForm(initial=status, prefix='avahi')
 
     return TemplateResponse(request, 'avahi.html',
                             {'title': _('Service Discovery'),