KubeControllerManagerDown #
Meaning #
KubeControllerManager has disappeared from Prometheus target discovery.
Impact #
The cluster is not functional and Kubernetes resources cannot be reconciled.
Full context
More about kube-controller-manager function can be found at https://kubernetes.io/docs/reference/command-line-tools-reference/kube-controller-manager/
Diagnosis #
TODO
Mitigation #
See old CoreOS docs in Web Archive