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Showing posts with the label Control Plane

How to check if the Kubernetes control plane is healthy

Disclaimer I have published this post on my work blog https://reece.tech previously. Why is this important We are running an on premise Kubernetes cluster (currently version 1.11.6) on Red Hat Linux 7.5 (in VMware). Most documentation (especially when it comes to master version upgrades) mentions checking that the control plane is healthy prior to performing any cluster changes. Obviously this is an important step to ensure consistency and repeatability - and also important during day to day management of your cluster, but how exactly do we do this? Our approach Our (multi master) Kubernetes control plane consists of a few different services / parts like etcd, kube-apiserver, scheduler, controller-manager and so on. Each component should be verified during this process. Starting simple Run  kubectl get nodes -o wide  to ensure all nodes are  Ready . Also check that the  master  servers have the  master  role. Also running  kubectl get cs  wi...