Nublado Major Version Migration¶

Currently we only discuss nublado v2 to nublado v3 migration; when the next major version comes about, we’ll add those instructions as well.

In general, when a new version appears, it will be called nublado and the previous version will be nubladoN where N is currently 2, and will be 3 when we do another major version (that is, the just-superseded version will be renamed on release of the newly-current one).

Nublado 2 to Nublado 3 Migration¶

Upgrading nublado v2 to nublado v3 is a complex process, and is usually done in stages; in the general case, each of these three stages would take place in a separate maintenance window as defined by site policy:

Enable nublado v3 on a non-default route (i.e. not /nb; in this document and in actuality, we use /n3). Run for some time allowing users to test the new spawner while still using nublado v2 by default
Switch nublado v3 to /nb and nublado v2 to an alternate route (e.g. /n2). Again, run for some time, keeping an eye out for any problems.
Once satisfied with the performance of nublado v3, disable the nublado2, cachemachine, and moneypenny applications (the functionality of the latter two are subsumed in nublado v3).
Once every environment is migrated, delete the nublado2, cachemachine, and moneypenny applications from Phalanx.

Enable nublado v3¶

Pre-deployment Preparation¶

The following tasks can be performed at any time, and should be performed ahead of your maintenance window to actually turn on the application.

Vault Secret Creation¶

The first thing you will need to do is to set up secrets for nublado (in future versions, this will require copying nublado to nubladoN, but nublado2 is the current name for version 2, so if you’re running an RSP, you already have those secrets set up correctly).

These secrets, stored in Vault, and presented by vault-secrets-operator are:

cryptkeeper_key: may be randomly generated; used internally by the Hub to encrypt authentication state in the session database.
crypto_key: may be randomly generated; used to encrypt cookies for user state in the browser session.
proxy_token: may be randomly generated; used to encrypt communications between the JupyterHub Configurable HTTP Proxy and the Hub.
hub_db_password: the password for the Hub session database; in nublado v3 this is a Postgres database; conventionally both the username and the database name are nublado3. In general you should be consuming a database as a service, in which case you will need to request this database from your DBAs and ask them the password. If you are instead running the internal database, you will need to create this database and grant permissions in the postgres application configuration.
slack_webhook: the Slack webhook allowing the JupyterLab controller to post status messages to Slack. This is the same one as used by, e.g. Gafaelfawr in your RSP instance.

Note that in future the secret setup and management will all be handled as part of Phalanx deployment, and you will no longer need to do this manually. However, at the present, you still do.

Enable the application¶

In the values file for your installation in the top-level Phalanx environments directory, set nublado: true.

Configure nublado v3¶

In the values file for your installation in applications/nublado, set up your site-specific values. The bulk of this work will be specifying the set of mount points you use for persistent user data. More than likely, you will use the same mount points for nublado v3 as you did for nublado v2, but the configuration syntax differs.

Note that if you do share persistent storage between nublado versions, the step about communicating with your users (below) goes from “important” to “critical”.

Create an alternate route¶

In the values file for your installation in applications/nublado, set the key jupyterhub.hub.baseUrl to /n3.

Communicate to user base¶

Let your users know about the new route and when it will be enabled (presumably, at the end of the next maintenance window). Announce that that maintenance window will be disruptive and will destroy any existing user sessions.

If you are using the same storage for users regardless of which spawner they’re coming in as, which you very likely are, in addition to the new route, you need to do your utmost to make it extremely clear that if they are testing the new route, it is vital to make sure that their labs from the previous route are shut down before changing from one route to the other. If they do not do this, it will at best create confusion as open notebooks will be saved every five minutes by each environment, thus bafflingly reverting changes, and at worst it will cause full-scale corruption of the files the user has open.

Silence Mobu complaints¶

Turn off mobu for notebooks if you’re using it, so that it doesn’t complain about the service outage. The easiest way to do this is, as an administrator, is to issue an HTTP DELETE against /mobu/flocks/<flockname>. Note that none of the silencing/disabling steps require any changes to Phalanx; they are all being performed in the ArgoCD UI or the Kubernetes CLI, and will be undone by a sync at the end of the maintenance window.

Disable logins¶

Disable user logins to nublado v2. This is most easily done by deleting the hub deployment from nublado v2.

Remove user sessions¶

Remove any user sessions. You can do this by deleting the namespace objects in the nublado-users application (which will also clean up anything within those namespaces) or by executing something like kubectl get ns | grep nublado2- | awk '{print $1}' | xargs kubectl delete ns.

Bring up applications¶

Synchronize the science-platform application. This will enable the nublado application, which contains nublado v3.
Synchronize the nublado application. This will turn on the nublado v3 spawner.
Test that you can get a lab and that that lab allows use of the command line and cell executions with the new spawner at /n3. If you find errors, troubleshoot them. Only proceed once you have the new spawner correctly spawning and shutting down labs.
Synchronize the nublado2 application. This will reenable the default spawner at /nb. At this point users will start returning (whether or not you call an all-clear, which you should not yet; users don’t pay attention to such things).
Re-enable mobu, if you disabled any of its flocks, by syncing the mobu application. Wait to make sure it’s correctly running notebooks, or test a few yourself.

Make nublado v3 the default¶

Pre-deployment Preparation¶

As before, these steps can be done at any time, and should be done in advance of the maintenance window.

Communicate to user base¶

Let your users know that /nb will refer to the new spawner, and that the old one will be available for a while at /n2, as well as the timeframe for these changes (presumably, at the end of the next maintenance window). Announce that that maintenance window will be disruptive and will destroy any existing user sessions.

If you are using the same storage for users regardless of which spawner they’re coming in as, which you very likely are, in addition to the new route, you need to do your utmost to make it extremely clear that if they intend to use both routes, it is vital to make sure that their labs from the previous route are shut down before changing from one route to the other. If they do not do this, it will at best create confusion as open notebooks will be saved every five minutes by each environment, thus bafflingly reverting changes, and at worst it will cause full-scale corruption of the files the user has open.

Change mobu configuration¶

If you are using mobu, change the instance-specific values file. In config.autostart, for each entry, set business.use_cachemachine to false. This is necessary because nublado 3 uses its Jupyterlab Controller to carry out the functions formerly performed by cachemachine.

Change nublado2 configuration¶

In the values file for your installation in applications/nublado2, set the key jupyterhub.hub.baseUrl to /n2.

Change nublado3 configuration¶

Remove the key jupyterhub.hub.baseUrl from the values file for your installation in applications/nublado.

This and the preceding step will make nublado v3 your default spawner on the /nb route and will relegate nublado v2 to the /n2 route

Deployment¶

During the deployment window:

Silence Mobu complaints¶

Turn off mobu for notebooks if you’re using it, so that it doesn’t complain about the service outage. The easiest way to do this is, as an administrator, is to issue an HTTP DELETE against /mobu/flocks/<flockname>. Note that none of the silencing/disabling steps require any changes to Phalanx; they are all being performed in the ArgoCD UI or the Kubernetes CLI, and will be undone by a sync at the end of the maintenance window.

Disable logins¶

Disable user logins to nublado v2 and nublado v3. This is most easily done by deleting the hub deployment from each of the nublado2 and nublado applications.

Remove user sessions¶

Remove any user sessions. You can do this by deleting the namespace objects in the nublado-users application (which will also clean up anything within those namespaces) or by executing something like for i in '' 2; do kubectl get ns | grep nublado${i}- | awk '{print $1}' | xargs kubectl delete ns; done.

Bring up applications¶

Synchronize the nublado2 application. This will move the default spawner to the /n2 route.
Test that you can get a lab and that that lab allows use of the command line and cell executions with the new spawner at /n2. If you find errors, troubleshoot them. If nublado v2 was working correctly beforehand, there should be no errors.
Synchronize the nublado application. This will turn on the nublado v3 spawner on the default route /nb. At this point users will start returning (whether or not you call an all-clear, which you should not yet; users don’t pay attention to such things).
Re-enable mobu, if you disabled it, by resynchronizing it from the ArgoCD UI. Wait to make sure it’s correctly running notebooks, or test a few yourself.

Disable nublado v2¶

Pre-deployment Preparation¶

As before, these steps can be done at any time, and should be done in advance of the maintenance window.

Communicate to user base¶

Let your users know that /n2 will no longer available. Announce that that maintenance window will be disruptive and will destroy any user sessions spawned via /n2. Hopefully that will be none or at least very few.

Turn off nublado v2¶

Delete the entries cachemachine: true, moneypenny: true, and nublado2: true from your instance-specific values file in environment.

Deployment¶

During the deployment window:

Synchronize the science-platform application. This will delete the nublado2, cachemachine, and moneypenny applications.
Remove any user sessions spawned by nublado2. This is harder to do from the UI: you will need to find any users in nublado-users with a namespace called nublado2-<username> and remove only those namespaces. From the CLI, it’s easier: kubectl get ns | grep nublado2- | awk '{print $1}' | xargs kubectl delete ns.
Delete the values files for your environment from Phalanx’s applications/nublado2, applications/cachemachine, and applications/moneypenny.

When Migration Is Complete For All Sites¶

Once all sites are running nublado v3, and none are still running nublado v2, the directories applications/nublado2, applications/moneypenny, and applications/cachemachine can all be deleted from Phalanx.
Remove the nublado2 secret from the vault enclave for all environments.
Remove the jupyterhub database and jovyan user from the postgres instance for each environment (or have the site DBA do it if it’s a database you don’t manage).