firewalld: Implement upgrading from 0.4.x to 0.6.x

- firewalld is always on an active. Running setup is not a problem.

- Installing new configuration and applying changes on top is more reliable.
  Changes to be done are not configuration settings but FreedomBox defaults.

Fixes: #1367.

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

plinth/modules/firewall/__init__.py

@@ -26,7 +26,7 @@ import plinth.service as service_module
 from plinth import actions, cfg
 from plinth.menu import main_menu
 from plinth.signals import service_enabled
-from plinth.utils import format_lazy
+from plinth.utils import Version, format_lazy
 
 from .manifest import backup
 
@@ -65,6 +65,21 @@ def setup(helper, old_version=None):
     _run(['setup'], superuser=True)
 
 
+def force_upgrade(helper, packages):
+    """Force upgrade firewalld to resolve conffile prompts."""
+    if 'firewalld' not in packages:
+        return
+
+    # firewalld 0.4.4.6-2 -> 0.6.x
+    package = packages['firewalld']
+    if Version(package['current_version']) >= Version('0.6') or \
+       Version(package['new_version']) < Version('0.6'):
+        return
+
+    helper.install(['firewalld'], force_configuration='new')
+    _run(['setup'], superuser=True)
+
+
 def get_enabled_status():
     """Return whether firewall is enabled"""
     output = _run(['get-status'], superuser=True)