Merge pull request #10226 from nextcloud/backport/10208/stable26

[stable26] Run occ commands in maintenance mode

Author: kesselb

admin_manual/configuration_server/occ_command.rst

@@ -16,6 +16,7 @@ occ command Directory
 ---------------------
 
 * :ref:`http_user_label`
+* :ref:`run_commands_in_maintenance_mode`
 * :ref:`apps_commands_label`
 * :ref:`background_jobs_selector_label`
 * :ref:`config_commands_label`
@@ -186,6 +187,25 @@ you need to specify ``--program occ`` after the ``--generate-hook``.
 If you want the completion to apply automatically for all new shell sessions, add the command to your
 shell's profile (eg. ``~/.bash_profile`` or ``~/.zshrc``).
 
+.. _run_commands_in_maintenance_mode:
+
+Run commands in maintenance mode
+--------------------------------
+
+In maintenance mode, no apps are loaded [1]_.
+
+Commands provided by apps are not available.
+
+The commands, available in maintenance mode, are integrated in Nextcloud server.
+A command may use events to communicate with other apps. An app can only react to an event when loaded. 
+
+Example: The command `user:delete` deletes a user account. UserDeletedEvent is emitted. Calendar app implements an event listener to delete user data [2]_. In maintenance mode, the Calendar app is not loaded, and hence the user data not deleted.
+
+Consider running such commands with maintenance mode off.
+
+.. [1] Exception: `The settings app is loaded <https://github.com/nextcloud/server/blob/75f17b60945e15effc3eea41393eef2b13937226/lib/base.php#L780>`_
+.. [2] `Calendar app event listener for UserDeletedEvent <https://github.com/nextcloud/calendar/blob/87e8586971a8676dc15a90f0cd969274678b7009/lib/Listener/UserDeletedListener.php>`_
+
 .. _apps_commands_label:
 
 Apps commands
@@ -606,10 +626,7 @@ user::
 
  sudo -u www-data php occ encryption:decrypt freda
 
-Users must have enabled recovery keys on their Personal pages. You must first
-put your Nextcloud server into :ref:`maintenance
-mode <maintenance_commands_label>` to prevent any user activity until
-decryption is completed.
+Users must have enabled recovery keys on their Personal pages.
 
 Note that if you do not have master key/recovery key enabled, you can ONLY
 decrypt files per user, one user at a time and NOT when in maintenance mode.
@@ -1151,6 +1168,7 @@ This example restores the deleted files of users molly and freda::
 
 User commands
 -------------
+.. note:: Read :ref:`run_commands_in_maintenance_mode` if you intend to use a user command in maintenance mode.
 
 The ``user`` commands create and remove users, reset passwords, display a simple
 report showing how many users you have, and when a user was last logged in::
@@ -1281,6 +1299,8 @@ authentication servers such as LDAP::
 Group commands
 --------------
 
+.. note:: Read :ref:`run_commands_in_maintenance_mode` if you intend to use a group command in maintenance mode.
+
 The ``group`` commands create and remove groups, add and remove users in
 groups, display a list of all users in a group::