...

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 victoria modules/tags, Run apt-get update && apt-get dist-upgrade && apt-get autoremove
   2. Reinstall the nodes with victoria 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

Barbican

Barbican must be stopped for upgrades, and can thus be performed on all barbican hosts at the same time. It might be an idea to keep one set of hosts stopped at old code in case of the need for a sudden roll-back.

1. Stop all barbican-services by adding the following keys to node-specific hiera, and then make sure to run puppet on the barbican hosts:

   1. barbican::worker::enabled: false

   2. apache::service_ensure: 'stopped'

2. Run puppet with the victoria modules/tags

3. Run apt dist-upgrade && apt-get autoremove

4. Run barbican-db-manage upgrade

5. Re-start barbican services by removing the keys added in step 1 and re-run puppet.

Magnum

Magnum must be stopped for upgrades, and can thus be performed on all magnum-hosts at the same time. It might be an idea to keep one set of hosts stopped at old code in case of the need for a sudden roll-back.

1. Reinstall the server to CentOS 8
2. Stop all magnum-services by adding the following keys to node-specific hiera, and then make sure to run puppet on the magnum hosts:

   1. magnum::conductor::enabled: false

   2. apache::service_ensure: 'stopped'

3. Run puppet with the victoria modules/tags

4. Run yum upgrade

5. Run su -s /bin/sh -c "magnum-db-manage upgrade" magnum

6. Re-start magnum services by removing the keys added in step 1 and re-run puppet.