Most of the time, upgrading Nublado can be done simply by syncing the application in Argo CD. There will be a brief outage for spawning new pods, but users with existing pods should be able to continue working.
Occasionally, new versions of JupyterHub will require a schema update. We do not routinely enable automatic schema updates currently, so JupyterHub will refuse to start if a database schema update is required. To enable schema updates, add:
jupyterhub: hub: db: upgrade: true
hub keys probably already exist in the
values-<environment>.yaml file, so just add the
db.upgrade setting in the correct spot.)
Then, JupyterHub will automatically upgrade its database when the new version starts.
You can then remove this configuration again if you’re worried about automatic updates misbehaving later.
Alternatively, if there’s a schema update, it’s probably a pretty major upgrade to JupyterHub, and it may be a better idea to shut down the Hub, remove all user namespaces, and then connect to the database and drop all tables; when the Hub is restarted, the correct schema will be generated. Obviously this will boot all users from the running system, but that may be appropriate for major upgrades.