GKE Cluster Upgrades

Control Plane Upgrade

Upgrading the Kubernetes version of the control plane is supported by the provider. To perform an upgrade you need to update the controlPlaneVersion in the spec of the GCPManagedControlPlane. Once the version has changed the provider will handle the upgrade for you.

Node Pool Machine Type

spec.instanceType on GCPManagedMachinePool is mutable. Changing it does not resize nodes in place: GKE performs the change as a rolling node replacement, so workload disruption is implied, the same as with the control plane upgrade above.

spec.upgradeSettings controls how disruptive that rollout is, at present only SURGE update strategies are supported, so strategy will also default to SURGE when unset:

spec:
  instanceType: n1-standard-4
  upgradeSettings:
    strategy: SURGE
    maxSurge: 10
    maxUnavailable: 5

The default values for maxSurge and maxUnavailable are 1 and 0 respectively.