Unable to use ldap groups in rsyslog

Issue

We have a centralized rsyslog server receiving logs of all our network equipment. This server is a client of a LDAP server. SSSD is used to authenticate users. In order to allow users to read the logs but not modify them, we have set the following directives

$FileOwner root
$FileGroup rsyslogusers
$FileCreateMode 0640

rsyslogusers is a ldap group, which contains all the LDAP users that need to access the logs.

The problem is that rsyslog starts prior to sssd. So, when rsyslog starts, the group rsyslogusers does not exists on the system. As rsyslog doesn't find the group, it creates logs using root:root. And so the users are unable to access the logs.