...

1. Run puppet with the wallaby modules/tags
2. Run apt dist-upgrade && apt-get autoremove
3. Run puppet and restart services

Heat

The rolling upgrade procedure for heat includes a step where you are supposed to create a new rabbit vhost. I don't want that. Therefore, this is the cold upgrade steps.

1. Set heat::api::enabled: false and heat::engine::enabled: false and heat::api_cfn::enabled: false in hiera to stop all services
2. Do one of:
   1. Run puppet with wallaby modules/tags, Run apt-get update && apt-get dist-upgrade && apt-get autoremove
   2. Reinstall the nodes with wallaby modules/tags
3. Run heat-manage db_sync on one of the api-nodes.

4. Remove the hiera keys that disabled the services and re-run puppet

Horizon

1. Run puppet with the wallaby modules/tags
2. run dnf upgrade

3. Yes this is weird: Login to all memcached servers, and run systemctl restart memcached
   1. This is only necessary when upgrading the first horizon server
4. Run puppet again
5. restart httpd