Meltdown protection if all nodes are not ready #386
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Avoid setting the LoadBalancers endpoints to an empty list if all nodes are reported as non-healthy.
This can help mitigating a scenario, where the
kubeletscannot reach the control plane to update their heartbeat, but theyawolcomponents still can. This can happen ifyawolmanages loadbalancers of a cluster it is not deployed in.In this scenario, the
kube-controller-managerwill quickly update all the nodes asNotReady, which in turn will trigger theyawol-cloud-controllerto remove alllb.Spec.Endpoints, which when picked up by theyawolets, results in no traffic reaching the cluster.Instead, I propose rather keeping a list of (non-terminating) nodes, even if they are considered as not ready. That way the workload might still be available. This "meltdown protection" will only kick in, if ALL nodes are unhealthy, so should have no effect on most LBs most of the time.