/etc/logrotate.d/waagent.logrotate is in walinuxagent 2.2.21+really2.2.20-0ubuntu3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7  | /var/log/waagent.log {
    compress
    monthly
    rotate 6
    notifempty
    missingok
}
 |