Fix notifications when using doas

simple_backup/simple_backup.py

@@ -12,8 +12,10 @@ Classes:
 """
 
 # Import libraries
+import traceback
 import sys
 import os
+import pwd
 from typing import Callable, List, Optional, ParamSpec, TypeVar, Union
 import warnings
 from functools import wraps
@@ -813,26 +815,46 @@ def _read_config(config_file, user: Optional[str] = None):
     return config_args
 
 
-def _notify(text: str) -> None:
+def _target_uid() -> int | None:
     euid = os.geteuid()
 
-    if euid == 0:
-        uid = os.getenv('SUDO_UID')
-    else:
-        uid = euid
+    if euid != 0:
+        return euid
+
+    if (val := os.getenv('SUDO_UID')) is not None:
+        return int(val)
+
+    if (name := os.getenv('DOAS_USER')) is not None:
+        try:
+            return pwd.getpwnam(name).pw_uid
+        except KeyError:
+            return None
+
+    return None
+
+
+def _notify(text: str) -> None:
+    euid = os.geteuid()
+    uid = _target_uid()
 
     if uid is None:
+        print('notify: no target uid (neither SUDO_UID nor DOAS_USER set)', file=sys.stderr)
+
         return
 
-    os.seteuid(int(uid))
-    os.environ['DBUS_SESSION_BUS_ADDRESS'] = f'unix:path=/run/user/{uid}/bus'
+    os.seteuid(uid)
 
-    obj = dbus.SessionBus().get_object('org.freedesktop.Notifications',
-                                       '/org/freedesktop/Notifications')
-    obj = dbus.Interface(obj, 'org.freedesktop.Notifications')
-    obj.Notify('', 0, '', 'simple_backup', text, [], {'urgency': 1}, 10000)
+    try:
+        os.environ['DBUS_SESSION_BUS_ADDRESS'] = f'unix:path=/run/user/{uid}/bus'
 
-    os.seteuid(int(euid))
+        obj = dbus.SessionBus().get_object('org.freedesktop.Notifications',
+                                           '/org/freedesktop/Notifications')
+        obj = dbus.Interface(obj, 'org.freedesktop.Notifications')
+        obj.Notify('simple_backup', 0, '', 'simple_backup', text, [], {'urgency': dbus.Byte(1)}, 10000)
+    except Exception:
+        traceback.print_exc()
+    finally:
+        os.seteuid(euid)
 
 
 def simple_backup() -> int: