I'm testing the Train7->Ussuri8 upgrade on a heat stack, following this document: OpenStack Docs: CentOS 8<https://docs.openstack.org/kolla-ansible/train/user/centos8.html#migrating-from-centos-7-to-centos-8> I used the instructions here to successfully remove a controller from the cluster: https://docs.openstack.org/kolla-ansible/train/user/adding-and-removing-host... Now I'm ready to add one, using the instructions here: https://docs.openstack.org/kolla-ansible/train/user/adding-and-removing-host... They say to run bootstrap-servers: kolla-ansible -i <inventory> bootstrap-servers [ --limit <limit> ] The question is, how to run it? My build server is running Centos 7 and has Python 2.7.5. Should I just download Ussuri to my existing build server, or do I need to build a new Centos 8 build server with Python 3? I read the "potential issues<https://docs.openstack.org/kolla-ansible/train/reference/deployment-and-bootstrapping/bootstrap-servers.html#rebootstrapping>" text but it's not obvious whether it is safe to run Ussuri bootstrap-servers on Train hosts. If I don't run bootstrap-servers on the Train controllers, then how does the new Ussuri controller get integrated (RMQ, MariaDB, etc.)? I apologize for the nonsense below. I have not been able to stop it from being attached to my external emails. E-MAIL CONFIDENTIALITY NOTICE: The contents of this e-mail message and any attachments are intended solely for the addressee(s) and may contain confidential and/or legally privileged information. If you are not the intended recipient of this message or if this message has been addressed to you in error, please immediately alert the sender by reply e-mail and then delete this message and any attachments. If you are not the intended recipient, you are notified that any use, dissemination, distribution, copying, or storage of this message or any attachment is strictly prohibited.