Kubernetes updates and upgrades
The provisioned version of the Kubernetes software for each cluster is displayed on a cluster's "Details" page in the Customer Portal:
There are no automatic upgrades. Version upgrades are applied during the maintenance window that you specify for your cluster. Whenever a new version of Kubernetes for your cluster becomes available, you will see an option to set the maintenance window for the upgrade.
Host OS updates and upgrades
We use Ubuntu Linux for master and worker nodes. Host OS security updates are applied immediately. Regular updates and upgrades are applied during the maintenance window that you specify for your cluster. Some updates/upgrades may require restart.