Kubernetes - debugging the API Server - and there's more

 Whilst trying to work out why my Kubernetes API Server ( kube-apiserver ) was crashing n' burning every 8-10 minutes, I found a few more useful things at which to look ...

kubectl get --raw='/readyz?verbose'

[+]ping ok
[+]log ok
[+]etcd ok
[+]informer-sync ok
[+]poststarthook/start-kube-apiserver-admission-initializer ok
[+]poststarthook/generic-apiserver-start-informers ok
[+]poststarthook/priority-and-fairness-config-consumer ok
[+]poststarthook/priority-and-fairness-filter ok
[+]poststarthook/start-apiextensions-informers ok
[+]poststarthook/start-apiextensions-controllers ok
[+]poststarthook/crd-informer-synced ok
[+]poststarthook/bootstrap-controller ok
[+]poststarthook/rbac/bootstrap-roles ok
[+]poststarthook/scheduling/bootstrap-system-priority-classes ok
[+]poststarthook/priority-and-fairness-config-producer ok
[+]poststarthook/start-cluster-authentication-info-controller ok
[+]poststarthook/aggregator-reload-proxy-client-cert ok
[+]poststarthook/start-kube-aggregator-informers ok
[+]poststarthook/apiservice-registration-controller ok
[+]poststarthook/apiservice-status-available-controller ok
[+]poststarthook/kube-apiserver-autoregistration ok
[+]autoregister-completion ok
[+]poststarthook/apiservice-openapi-controller ok
[+]shutdown ok
readyz check passed

kubectl describe pod `kubectl get pods --namespace kube-system | grep apiserver | awk '{print $1}'` --namespace kube-system

...

Events:

  Type    Reason   Age    From     Message

  ----    ------   ----   ----     -------

  Normal  Pulled   5m17s  kubelet  Container image "k8s.gcr.io/kube-apiserver:v1.21.0" already present on machine

  Normal  Created  5m17s  kubelet  Created container kube-apiserver

  Normal  Started  5m16s  kubelet  Started container kube-apiserver

PS managed to resolve the kube-apiserver crash issue ... ask me how ?