Kubernetes Metrics Server

Kubernetes

Set-up

kubeadm doesn’t install metrics server component during its initialization. We have to install it separately.

To verify this, if you run the top command, you will see the Metrics API not available error.

root@master-node:~# kubectl top nodes
error: Metrics API not available

To install the metrics server, execute the following metric server manifest file. It deploys metrics server version v0.6.2

kubectl apply -f https://raw.githubusercontent.com/yanboyang713/kubeadm-scripts/main/manifests/metrics-server.yaml

This manifest is taken from the official metrics server repo. I have added the —kubelet-insecure-tls flag to the container to make it work in the local setup and hosted it separately. Or else, you will get the following error.

because it doesn't contain any IP SANs" node=""

Once the metrics server objects are deployed, it takes a minute for you to see the node and pod metrics using the top command.

kubectl top nodes

You should be able to view the node metrics as shown below.

root@master-node:/home/vagrant# kubectl top nodes
NAME            CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
master-node     111m         5%     1695Mi          44%
worker-node01   28m          2%     1078Mi          57%
worker-node02   219m         21%    980Mi           52%

You can also view the pod CPU and memory metrics using the following command.

kubectl top pod -n kube-system