Metrics Server installation in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Metrics Server in Kubernetes?

The Metrics Server collects resource usage data like CPU and memory from nodes and pods. It helps Kubernetes make decisions for scaling and monitoring.

beginner

Which command installs the Metrics Server using kubectl?

kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

intermediate

Why might you need to edit the Metrics Server deployment after installation?

You may need to add flags like --kubelet-insecure-tls if your cluster uses self-signed certificates, to allow Metrics Server to communicate with kubelets.

beginner

How can you verify that the Metrics Server is running correctly?

Run kubectl get deployment metrics-server -n kube-system to check the deployment status and kubectl top nodes to see if metrics are available.

intermediate

What role does the Metrics Server play in Horizontal Pod Autoscaling (HPA)?

Metrics Server provides the resource usage data that HPA uses to decide when to scale pods up or down based on CPU or memory usage.

Which command installs the Metrics Server in Kubernetes?

A kubectl create deployment metrics-server

B kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

C kubectl install metrics-server

D kubectl get metrics-server

The correct command applies the official Metrics Server manifest from the GitHub repository.

What does the Metrics Server collect from Kubernetes nodes and pods?

A Network traffic data

B Pod logs

C Resource usage data like CPU and memory

D Persistent volume usage

Metrics Server collects CPU and memory usage metrics, not logs or network data.

If Metrics Server cannot communicate with kubelets due to TLS errors, what flag might you add?

A --kubelet-insecure-tls

B --enable-logging

C --allow-unauthenticated

D --disable-metrics

The --kubelet-insecure-tls flag allows Metrics Server to skip TLS verification for kubelet communication.

How do you check if Metrics Server is successfully deployed?

A kubectl logs metrics-server

B kubectl get pods -n default

C kubectl describe node

D kubectl get deployment metrics-server -n kube-system

Checking the deployment status in the kube-system namespace confirms if Metrics Server is running.

What Kubernetes feature depends on Metrics Server for scaling decisions?

A Horizontal Pod Autoscaler (HPA)

B kubectl rollout

C kubectl exec

D Persistent Volume Claims

HPA uses Metrics Server data to scale pods based on resource usage.

Explain the steps to install and verify the Metrics Server in a Kubernetes cluster.

Think about installation, deployment check, and metrics verification commands.

Describe why Metrics Server might need configuration changes after installation and what those changes could be.

Consider common issues with self-signed certificates in clusters.