draft user renaming docs (tpo/tpa/team#41681)

howto.md

@@ -31,6 +31,7 @@ various procedures not necessarily associated with a specific service.
  * [quintex](howto/quintex)
  * [raid](howto/raid)
  * [rename-a-host](howto/rename-a-host)
+ * [rename-a-user](howto/rename-a-user)
  * [retire-a-host](howto/retire-a-host)
  * [retire-a-user](howto/retire-a-user)
  * [upgrades](howto/upgrades)

howto/rename-a-user.md

+[[_TOC_]]
+
+This document explains how to handle requests to rename a user account.
+
+# Requirements
+
+- the new LDAP username
+- the new "full name"
+- a new or updated GPG key with the new email
+- a new mail forwarding address, if needed
+
+# Main procedure
+
+1. Update `account-keyring.git` with the new (or updated) GPG key
+
+2. With `ldapvi`, update the user and group names in the LDAP database
+   (including the DN), along with the new GPG fingerprint if a new key is to be
+   associated with the account and forwarding address if applicable
+
+3. Using `cumin`, rename home directories on hosts
+
+4. Optionally, add the previous forwarding to the virtual alias map on `eugeni`
+
+5. Update the information on the main website
+
+# GitLab
+
+GitLab users may rename their own accounts with the User Settings panel.
+
+# Nextcloud
+
+Changing the login name is [not supported][] at all in Nextcloud, only the
+display name can be changed.
+
+[not supported]: https://docs.nextcloud.com/server/latest/admin_manual/configuration_user/user_configuration.html#renaming-a-user
+
+If a new account is created as part or the renaming process, it's possible to
+"transfer" files and shares from one account to the other using the
+[files:transfer-ownership][] command via the CLI. This particular option is
+however untested, and TPA doesn't have access to the hosted Nextcloud CLI.
+
+[files:transfer-ownership]: https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/occ_command.html#transfer