BGP-agents

Run puppet with the stein the train modules/tags
Run apt dist-upgrade
Rerun puppet and restart the service
1. systemctl restart neutron-bgp-dragent.service

Network-nodes

Run puppet with the stein the train modules/tags
Run apt dist-upgrade
Rerun puppet and restart the service
1. systemctl restart ovsdb-server
2. systemctl restart neutron-dhcp-agent.service neutron-l3-agent.service neutron-metadata-agent.service neutron-openvswitch-agent.service neutron-ovs-cleanup.service

Run puppet with train modules/tags
Delete /var/lib/placement/placement.sqlite if it exists
Run apt-get purge placement-api placement-common python3-placement && apt-get autoremove && apt-get dist-upgrade
Run puppet again
Run placement-manage db online_data_migrations

To upgrade nova without any downtime, follow this procedure

Before the upgrades can be started it is important that all data from previous nova-releases are migrated to stein's release. This is done like so:

Run nova-manage db online_data_migrations on an API node. Ensure that it reports that nothing more needs to be done.

In the node-specific hiera, disable the services at the first node you would like to upgrade with the keys
1. apache::service_ensure: 'stopped'
Run puppet with the train modules/tags
Run apt dist-upgrade && apt-get autoremove
Run nova-manage api_db sync
Run nova-manage db sync
Re-enable placement API on the upgraded node and disable it on the other nodes. This is because the other services needs the placement API to be updated first
1. Remove apache::service_ensure: 'stopped' from the upgraded node's hiera file
2. Set it on all the other nodes and run puppet
Upgrade the rest of the nodes (basically run step 2-4, re-run puppet and restart nova-api and apache2)
Remove the hiera keys that disabled the services, and re-run puppet