Provide consumption-friendly events for Cluster Autoscaler

[tomkerkhove]

Provide consumption-friendly events for Cluster Autoscaler

[tomkerkhove]

https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/FAQ.md#what-events-are-emitted-by-ca

Whenever Cluster Autoscaler adds or removes nodes it will create events
describing this action. It will also create events for some serious
errors. Below is the non-exhaustive list of events emitted by CA (new events may
be added in future):

• on kube-system/cluster-autoscaler-status config map:
  • ScaledUpGroup - CA increased the size of node group, gives
    both old and new group size.
  • ScaleDownEmpty - CA removed a node with no pods running on it (except
    system pods found on all nodes).
  • ScaleDown - CA decided to remove a node with some pods running on it.
    Event includes names of all pods that will be rescheduled to drain the
    node.
• on nodes:
  • ScaleDown - CA is scaling down the node. Multiple ScaleDown events may be
    recorded on the node, describing status of scale-down operation.
  • ScaleDownFailed - CA tried to remove the node, but failed. The event
    includes error message.
• on pods:
  • TriggeredScaleUp - CA decided to scale up cluster to make place for this
    pod.
  • NotTriggerScaleUp - CA couldn't find node group that can be scaled up to
    make this pod schedulable.
  • ScaleDown - CA will try to evict this pod as part of draining the node.

[tomkerkhove]

Closing now that we have dedicated ones