config: Use privileged decorator for set-hostname action

Tests:

- Running flake8 as in .gitlab-ci.yml works.
- Changes the hostname works and it is updated in /etc/hostname
  - Avahi daemon is restarted

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

.gitlab-ci.yml

@@ -16,7 +16,7 @@ code-quality:
   stage: test
   needs: []
   script:
-    - python3 -m flake8 --exclude actions/domainname-change,actions/hostname-change,actions/networks container plinth actions/*
+    - python3 -m flake8 --exclude actions/domainname-change,actions/networks container plinth actions/*
 
 unit-tests:
   stage: test

actions/hostname-change

@@ -1,8 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: AGPL-3.0-or-later
-
-hostname="$1"
-
-hostnamectl set-hostname --transient --static "$hostname"
-
-service avahi-daemon restart

plinth/modules/config/privileged.py

@@ -3,6 +3,7 @@
 
 import os
 import pathlib
+import subprocess
 
 import augeas
 
@@ -19,6 +20,15 @@ FREEDOMBOX_APACHE_CONFIG = os.path.join(APACHE_CONF_ENABLED_DIR,
 JOURNALD_FILE = pathlib.Path('/etc/systemd/journald.conf.d/50-freedombox.conf')
 
 
+@privileged
+def set_hostname(hostname: str):
+    """Set system hostname using hostnamectl."""
+    subprocess.run(
+        ['hostnamectl', 'set-hostname', '--transient', '--static', hostname],
+        check=True)
+    action_utils.service_restart('avahi-daemon')
+
+
 def load_augeas():
     """Initialize Augeas."""
     aug = augeas.Augeas(flags=augeas.Augeas.NO_LOAD +

plinth/modules/config/views.py

@@ -102,7 +102,7 @@ class ConfigAppView(views.AppView):
 
 
 def set_hostname(hostname):
-    """Sets machine hostname to hostname"""
+    """Set machine hostname and send signals before and after."""
     old_hostname = config.get_hostname()
     domainname = config.get_domainname()
 
@@ -114,7 +114,7 @@ def set_hostname(hostname):
                                     new_hostname=hostname)
 
     LOGGER.info('Changing hostname to - %s', hostname)
-    actions.superuser_run('hostname-change', [hostname])
+    privileged.set_hostname(hostname)
 
     LOGGER.info('Setting domain name after hostname change - %s', domainname)
     actions.superuser_run('domainname-change', [domainname])