uninstall

Example: explicit uninstall

Deleting a NodeWright, or relabelling a node out of its selector, leaves the host as the packages left it, unless the package has opted in to uninstall (below), in which case deleting the NodeWright runs the uninstall first. Reversing a change is otherwise a separate, deliberate step: uninstall.

A package opts in with uninstall.enabled: true, which declares that it ships uninstall and uninstall_check steps. Setting uninstall.apply: true then runs them on every target node.

This example's package writes a marker file on the host and removes it again.

Run it

NODE=<node-name>
kubectl label node "$NODE" nodewright.nvidia.com/example=uninstall
kubectl apply -f examples/uninstall/nodewright.yaml
kubectl get nodewright uninstall-demo -w

Once it is complete, the node's record of the package shows it installed:

kubectl get node "$NODE" \
  -o jsonpath='{.metadata.annotations.nodewright\.nvidia\.com/nodeState_uninstall-demo}'

The file is on the host. Check from a debug pod: chroot /host cat /etc/nodewright-example/uninstall/marker.

Uninstall it

Flip apply to true:

kubectl patch nodewright uninstall-demo --type=merge \
  -p '{"spec":{"packages":{"marker":{"uninstall":{"apply":true}}}}}'

The operator runs uninstall.sh, then uninstall_check.sh, which fails unless the file is gone. When the check passes, the package disappears from the node's nodeState_uninstall-demo annotation. Absent means uninstalled: there is no "uninstalled" state to look for.

kubectl nodewright package status marker --nodewright uninstall-demo

Now it is safe to remove the package from the spec. The webhook would have rejected that before the uninstall finished, which is what stops you from orphaning files on a host.

Things to try

• Cancel. Patch apply back to false while the uninstall is running. The package installs again. (A package that declares an interrupt can no longer be cancelled once its uninstall interrupt has fired.)
• Uninstall on delete. Reinstall, then kubectl delete the NodeWright. A finalizer runs the uninstall on every node before the resource goes away.
• Downgrade. Lower version while apply is false. The webhook rejects it: to downgrade a package with uninstall.enabled, uninstall it first.

Clean up

kubectl delete -f examples/uninstall/nodewright.yaml
kubectl label node "$NODE" nodewright.nvidia.com/example-

Related

• Explicit Uninstall: every workflow, the deletion edge cases, and how uninstall interacts with dependsOn
• Lifecycle of a NodeWright: the uninstall lane