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

Prerequisites:

• This documents expects that your cloud is deployed with a recent yoga 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 '6.1'
    
    • 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):

1. Set apache::service_ensure: 'stopped' in hiera for the node that you are upgrading
2. Run puppet with the zed modules/tags, run apt-get dist-upgrade, and run puppet again
3. Run keystone-manage doctor and ensure nothing is wrong
4. Run keystone-manage db_sync --expand
   1. Returns nothing
5. At this point, you may restart apache2 on this node
   1. Remove the  apache::service_ensure: 'stopped' previously set in hiera.
6. Upgrade keystone on the other nodes, one at a time
   1. Basically run step 1, 2 and 5 on the other nodes
7. 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:

1. Select which glance-server to upgrade first.
   1. In the node-specific hiera for this host you should set: 
      1. glance::api::enabled: false
      2. apache::service_ensure: 'stopped'
      3. apache::mod::wsgi::package_name: 'libapache2-mod-wsgi-py3'
      4. apache::mod::wsgi::mod_path: '/usr/lib/apache2/modules/mod_wsgi.so'
2. Run puppet with the zed modules/tags, run apt-get dist-upgrade, and run puppet again
3. Remove the glance::api::enable: false and apache::service_ensure: 'stopped' 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.
4. Upgrade the rest of the glance hosts (ie; step 2 for each of the remaining glance hosts)

Cinder

To upgrade cinder without any downtime, follow this procedure

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

   1. apache::service_ensure: 'stopped'

   2. cinder::scheduler::enabled: false

   3. cinder::volume::enabled: false

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

Neutron

API-nodes

1. Add the following to the node-specific hiera-file for neutronapi-hosts:
   1. apache::mod::wsgi::package_name: 'libapache2-mod-wsgi-py3'
   2. apache::mod::wsgi::mod_path: '/usr/lib/apache2/modules/mod_wsgi.so'
2. Pick the first node, and add the following to the nodes hiera-file:
   1. apache::service_ensure: 'stopped'
   2. neutron::server::enabled: false
3. Run puppet with the zed modules/tags, Run apt-get autoremove && apt-get dist-upgrade
4. Run neutron-db-manage upgrade --expand
5. Remove the lines stopping neutron-server.service and apache2 in the hiera node-file, and re-run puppet
6. Upgrade the rest of the API-nodes (repeating step 3 and then reboot.)
7. Stop all neutron-server and apache processes for a moment, and run:
   
   1. neutron-db-manage upgrade --contract
8. Re-start the neutron-server and apache processes

BGP-agents

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

1. Either do the upgrade-procedure:
   1. Run puppet with the zed modules/tags
   2. Run apt dist-upgrade
   3. Rerun puppet and restart the service
      1. systemctl restart neutron-bgp-dragent.service

      2. or simply reboot
2. Or simply re-install the node using the zed modules/tags.

Network-nodes

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

1. Run puppet with the yoga modules/tags
2. Run apt dist-upgrade
3. Rerun puppet and restart the service (or simply reboot the host).
   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
4. Verify that routers on the node actually work.

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 apache::service_ensure: false, heat::api::enabled: false, heat::engine::enabled: false and heat::api_cfn::enabled: false in hiera to stop all services
2. Add the following to the node-specific hiera file for heat-api nodes:
   1. apache::mod::wsgi::package_name: 'libapache2-mod-wsgi-py3'
   2. apache::mod::wsgi::mod_path: '/usr/lib/apache2/modules/mod_wsgi.so'
3. Do one of:
   1. Run puppet with zed modules/tags, Run apt-get update && apt-get dist-upgrade && apt-get autoremove
   2. Reinstall the nodes with zed modules/tags
4. Run heat-manage db_sync on one of the api-nodes.

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