users: Rename a POSIX user when Plinth user is renamed

actions/rename-user

@@ -0,0 +1,36 @@
+#!/bin/sh
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# Must be run as root.
+
+old_username="$1"
+new_username="$2"
+
+getent passwd "$old_username"
+if [ $? -ne 0 ]; then
+    echo "Failed: user not found"
+    exit
+fi
+
+usermod -l "$new_username" "$old_username"
+if [ $? -eq 0 ]; then
+    echo "Success: user renamed"
+else
+    echo "Failed: user rename failed"
+    exit 2
+fi

plinth/modules/users/forms.py

@@ -88,6 +88,14 @@ class UserUpdateForm(forms.ModelForm):
                     self.request,
                     _('Setting active status for POSIX system user failed.'))
 
+            try:
+                if self.username != user.get_username():
+                    actions.superuser_run('rename-user',
+                                          [self.username, user.get_username()])
+            except ActionError:
+                messages.error(self.request,
+                               _('Renaming POSIX system user failed.'))
+
         return user