tftpboot/preseed/finish/logrotate/dpkg

/var/log/dpkg.log {
  weekly
  rotate 12
  compress
  delaycompress
  missingok
  notifempty
  create 644 root root
  olddir /var/log/old_logs
}
/var/log/alternatives.log {
  weekly
  rotate 12
  compress
  delaycompress
  missingok
  notifempty
  create 644 root root
  olddir /var/log/old_logs
}