shadowsocks: Use privileged decorator for actions

Tests:

- Functional tests work
- Initial setup works
- Setting configuration works, correct configuration is updated in the
  configuration files and app shows the values correctly.

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

plinth/modules/shadowsocks/__init__.py

@@ -1,12 +1,9 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-FreedomBox app to configure Shadowsocks.
-"""
+"""FreedomBox app to configure Shadowsocks."""
 
 from django.urls import reverse_lazy
 from django.utils.translation import gettext_lazy as _
 
-from plinth import actions
 from plinth import app as app_module
 from plinth import cfg, frontpage, menu
 from plinth.daemon import Daemon
@@ -15,7 +12,7 @@ from plinth.modules.firewall.components import Firewall
 from plinth.package import Packages
 from plinth.utils import format_lazy
 
-from . import manifest
+from . import manifest, privileged
 
 _description = [
     _('Shadowsocks is a lightweight and secure SOCKS5 proxy, designed to '
@@ -85,5 +82,5 @@ class ShadowsocksApp(app_module.App):
     def setup(self, old_version):
         """Install and configure the app."""
         super().setup(old_version)
-        actions.superuser_run('shadowsocks', ['setup'])
+        privileged.setup()
         self.enable()

plinth/modules/shadowsocks/forms.py

@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-FreedomBox app for configuring Shadowsocks.
-"""
+"""FreedomBox app for configuring Shadowsocks."""
 
 from django import forms
 from django.utils.translation import gettext_lazy as _
@@ -22,10 +20,10 @@ METHODS = [('chacha20-ietf-poly1305',
 
 
 class TrimmedCharField(forms.CharField):
-    """Trim the contents of a CharField"""
+    """Trim the contents of a CharField."""
 
     def clean(self, value):
-        """Clean and validate the field value"""
+        """Clean and validate the field value."""
         if value:
             value = value.strip()
 
@@ -33,7 +31,8 @@ class TrimmedCharField(forms.CharField):
 
 
 class ShadowsocksForm(forms.Form):
-    """Shadowsocks configuration form"""
+    """Shadowsocks configuration form."""
+
     server = TrimmedCharField(label=_('Server'),
                               help_text=_('Server hostname or IP address'))
 

plinth/modules/shadowsocks/privileged.py

@@ -1,42 +1,24 @@
-#!/usr/bin/python3
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-Helper script for configuring Shadowsocks.
-"""
+"""Configure Shadowsocks."""
 
-import argparse
 import json
 import os
 import pathlib
 import random
 import string
-import sys
 from shutil import move
+from typing import Union
 
 from plinth import action_utils
-from plinth.modules.shadowsocks import ShadowsocksApp
+from plinth.actions import privileged
 
 SHADOWSOCKS_CONFIG_SYMLINK = '/etc/shadowsocks-libev/freedombox.json'
 SHADOWSOCKS_CONFIG_ACTUAL = \
     '/var/lib/private/shadowsocks-libev/freedombox/freedombox.json'
 
 
-def parse_arguments():
-    """Return parsed command line arguments as dictionary."""
-    parser = argparse.ArgumentParser()
-    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')
-
-    subparsers.add_parser('setup', help='Perform initial setup steps')
-    subparsers.add_parser('get-config',
-                          help='Read and print JSON config to stdout')
-    subparsers.add_parser('merge-config',
-                          help='Merge JSON config from stdin with existing')
-
-    subparsers.required = True
-    return parser.parse_args()
-
-
-def subcommand_setup(_):
+@privileged
+def setup():
     """Perform initial setup steps."""
     # Only client socks5 proxy is supported for now. Disable the
     # server component.
@@ -76,16 +58,16 @@ def subcommand_setup(_):
     if not wrong_state_dir.is_symlink() and wrong_state_dir.is_dir():
         wrong_state_dir.rmdir()
 
+    from plinth.modules.shadowsocks import ShadowsocksApp
     if action_utils.service_is_enabled(ShadowsocksApp.DAEMON):
         action_utils.service_restart(ShadowsocksApp.DAEMON)
 
 
-def subcommand_get_config(_):
+@privileged
+def get_config() -> dict[str, Union[int, str]]:
     """Read and print Shadowsocks configuration."""
-    try:
-        print(open(SHADOWSOCKS_CONFIG_SYMLINK, 'r', encoding='utf-8').read())
-    except Exception:
-        sys.exit(1)
+    config = open(SHADOWSOCKS_CONFIG_SYMLINK, 'r', encoding='utf-8').read()
+    return json.loads(config)
 
 
 def _merge_config(config):
@@ -103,26 +85,13 @@ def _merge_config(config):
     open(SHADOWSOCKS_CONFIG_SYMLINK, 'w', encoding='utf-8').write(new_config)
 
 
-def subcommand_merge_config(_):
+@privileged
+def merge_config(config: dict[str, Union[int, str]]):
     """Configure Shadowsocks."""
-    config = sys.stdin.read()
-    config = json.loads(config)
     _merge_config(config)
 
     # Don't try_restart because initial configuration may not be valid so
     # shadowsocks will not be running even when enabled.
+    from . import ShadowsocksApp
     if action_utils.service_is_enabled(ShadowsocksApp.DAEMON):
         action_utils.service_restart(ShadowsocksApp.DAEMON)
-
-
-def main():
-    """Parse arguments and perform all duties."""
-    arguments = parse_arguments()
-
-    subcommand = arguments.subcommand.replace('-', '_')
-    subcommand_method = globals()['subcommand_' + subcommand]
-    subcommand_method(arguments)
-
-
-if __name__ == '__main__':
-    main()

plinth/modules/shadowsocks/views.py

@@ -1,21 +1,18 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
-"""
-FreedomBox app for configuring Shadowsocks.
-"""
-
-import json
+"""FreedomBox app for configuring Shadowsocks."""
 
 from django.contrib import messages
 from django.utils.translation import gettext_lazy as _
 
-from plinth import actions, views
-from plinth.errors import ActionError
+from plinth import views
 
+from . import privileged
 from .forms import ShadowsocksForm
 
 
 class ShadowsocksAppView(views.AppView):
     """Configuration view for Shadowsocks local socks5 proxy."""
+
     app_id = 'shadowsocks'
     form_class = ShadowsocksForm
 
@@ -23,10 +20,8 @@ class ShadowsocksAppView(views.AppView):
         """Get initial values for form."""
         status = super().get_initial()
         try:
-            configuration = actions.superuser_run('shadowsocks',
-                                                  ['get-config'])
-            status.update(json.loads(configuration))
-        except ActionError:
+            status.update(privileged.get_config())
+        except Exception:
             status.update({
                 'server': '',
                 'server_port': 8388,
@@ -54,8 +49,7 @@ class ShadowsocksAppView(views.AppView):
                 'method': new_status['method'],
             }
 
-            actions.superuser_run('shadowsocks', ['merge-config'],
-                                  input=json.dumps(new_config).encode())
+            privileged.merge_config(new_config)
             messages.success(self.request, _('Configuration updated'))
 
         return super().form_valid(form)