This article summarizes the steps required to upgrade from the xena release to the yoga release of openstack.

Prerequisites:

This documents expects that your cloud is deployed with a recent xena tag of the ntnuopenstack repository.
You have a recent mysql backup in case things go south.
If you want to do a rolling upgrade, the following key should be set in hiera long enough in advance that all hosts have had an puppet-run to apply it:
- nova::upgrade_level_compute: '6.0'
- When the upgrade is finished - the key should still be set to '6.0'
  - (Yoga is 6.0; zed is 6.1, so the next release needs a change here...)
  - These version-numbers can be correlated to release-name in the file /usr/lib/python3/dist-packages/nova/compute/rpcapi.py

The recommended order to upgrade the services are listed below:

Keystone

This is the zero downtime approach

Before you begin

Login to a mysql node, start the mysql CLI, and run set global log_bin_trust_function_creators=1;

Upgrade-steps (start with a single node):

Set apache::service_ensure: 'stopped' in hiera for the node that you are upgrading
Run puppet with the yoga modules/tags, run apt-get dist-upgrade, and run puppet again
1. The first puppet-run complains a lot; as it changes its logic for openstack auth all openstack-changes fails; run puppet once more if this bugs you
Run keystone-manage doctor and ensure nothing is wrong
Run keystone-manage db_sync --expand
1. Returns nothing
Run keystone-manage db_sync --migrate
1. Returns nothing
At this point, you may restart apache2 on this node
1. Remove the apache::service_ensure: 'stopped' previously set in hiera.
Upgrade keystone on the other nodes, one at a time
1. Basically run step 1, 2 and 6 on the other nodes
When all nodes are upgraded, perform the final DB sync
1. keystone-manage db_sync --contract

Glance

To upgrade glance without any downtime you would need to follow the following procedure:

Select which glance-server to upgrade first.
1. In the node-specific hiera for this host you should set: glance::api::enabled: false
Run puppet with the yoga modules/tags, run apt-get dist-upgrade, and run puppet again
Run glance-manage db expand
Run glance-manage db migrate
Remove the glance::api::enable: false from the node-specific hiera, and run puppet again. This would re-start the glance api-server on this host.
1. Test that this api-server works.
Upgrade the rest of the glance hosts (ie; step 2 for each of the remaining glance hosts)
Run glance-manage db contract on one of the glance-nodes.

Enable glance quotas through keystone unified limits

If you want to add quotas to limit tenants possibility to use too much storage for their images you need to register default-quotas in keystone. Substitute "SkyLow" with the relevant region-name:

# Default-quota of 10 images and 50GB
openstack registered limit create --service glance --region SkyLow --default-limit 50000 image_size_total 
openstack registered limit create --service glance --region SkyLow --default-limit 10 image_count_total
# Default-quota of 5 images and 50GB which is currently being uploaded.
openstack registered limit create --service glance --region SkyLow --default-limit 50000 image_stage_total
openstack registered limit create --service glance --region SkyLow --default-limit 5 image_count_uploading

Enable the unified limit integration for glance by adding the following lines in hiera:

ntnuopenstack::glance::endpoint::internal::id: '<GLANCE INTERNAL ENDPOINT ID>'
ntnuopenstack::glance::keystone::limits: true

Cinder

To upgrade cinder without any downtime, follow this procedure

Add the following three lines to the node-file of the first node you would like to upgrade:

```
apache::service_ensure: 'stopped'
```
```
cinder::scheduler::enabled: false
```
```
cinder::volume::enabled: false
```

Run puppet with the yoga modules/tags, run apt-get dist-upgrade, and run puppet again
Run cinder-manage db sync && cinder-manage db online_data_migrations
Remove the lines added at step 1, re-run puppet, and test that the upgraded cinder version works.
Perfom step 2 for the rest of the cinder nodes

Neutron

API-nodes

Pick the first node, and run puppet with the yoga modules/tags, Run apt-get autoremove && apt-get dist-upgrade
Run neutron-db-manage upgrade --expand
Restart neutron-server.service and rerun puppet
Upgrade the rest of the API-nodes (repeating step 1, and 3)
Stop all neutron-server processes for a moment, and run:
1. neutron-db-manage upgrade --contract
Re-start the neutron-server processes

BGP-agents

Either you simply reinstall the node with yoga modules/tags; or you follow the following list:

Run puppet with the yoga modules/tags
Run apt dist-upgrade
Rerun puppet and restart the service
1. systemctl restart neutron-bgp-dragent.service
2. or simply reboot

Network-nodes