Get familiar with some key concepts of cluster management

This article offers a back-to-basics approach to help you understand several actions that can be done on a cluster’s nodes.

Our Test Cluster

Let’s consider a newly created kubeadm cluster containing one master and two worker nodes:

$ kubectl get nodes
NAME    STATUS   ROLES                  AGE   VERSION
k8s-1   Ready    control-plane,master   18m   v1.20.0
k8s-2   Ready    <none>                 18m   v1.20.0
k8s-3   Ready    <none>                 18m   v1.20.0

First, we will install Kubernetes Operational View (aka kube-ops-view). This application is very handy for seeing all the pods running in a cluster at a glance. There are currently 14 pods running:

• Two of them are in the default namespace and are related to kube-obs-view. They are in the top left corners of k8s-2 and k8s-3 in the screenshot below
• The 12 others are in the kube-system namespaces: kube-api-server, etcd, kube-controller-manager, kube-scheduler, kube-proxy (x3), weave-net (x3), core-dns (x2).

#kubernetes #devops #node #node.js