Most Recent Linux Foundation CKA Exam Dumps

SOLUTION:

[student@node-1] > ssh ek8s

kubectl cordon k8s-master

kubectl drain k8s-master --delete-local-data --ignore-daemonsets --force

apt-get install kubeadm=1.20.1-00 kubelet=1.20.1-00 kubectl=1.20.1-00 --disableexcludes=kubernetes

kubeadm upgrade apply 1.20.1 --etcd-upgrade=false

systemctl daemon-reload

systemctl restart kubelet

kubectl uncordon k8s-master

solution

Persistent Volume

A persistent volume is a piece of storage in a Kubernetes cluster. PersistentVolumes are a cluster-level resource like nodes, which don't belong to any namespace. It is provisioned by the administrator and has a particular file size. This way, a developer deploying their app on Kubernetes need not know the underlying infrastructure. When the developer needs a certain amount of persistent storage for their application, the system administrator configures the cluster so that they consume the PersistentVolume provisioned in an easy way.

Creating Persistent Volume

kind: PersistentVolume

apiVersion: v1

metadata:

name:app-data

spec:

capacity: # defines the capacity of PV we are creating

storage: 2Gi #the amount of storage we are tying to claim

accessModes: # defines the rights of the volume we are creating

- ReadWriteMany

hostPath:

path: '/srv/app-data' # path to which we are creating the volume

Challenge

Create a Persistent Volume named app-data, with access mode ReadWriteMany, storage classname shared, 2Gi of storage capacity and the host path /srv/app-data.

2. Save the file and create the persistent volume.

3. View the persistent volume.

Our persistent volume status is available meaning it is available and it has not been mounted yet. This status will change when we mount the persistentVolume to a persistentVolumeClaim.

PersistentVolumeClaim

In a real ecosystem, a system admin will create the PersistentVolume then a developer will create a PersistentVolumeClaim which will be referenced in a pod. A PersistentVolumeClaim is created by specifying the minimum size and the access mode they require from the persistentVolume.

Challenge

Create a Persistent Volume Claim that requests the Persistent Volume we had created above. The claim should request 2Gi. Ensure that the Persistent Volume Claim has the same storageClassName as the persistentVolume you had previously created.

kind: PersistentVolume

apiVersion: v1

metadata:

name:app-data

spec:

accessModes:

- ReadWriteMany

resources:

requests:

storage: 2Gi

storageClassName: shared

2. Save and create the pvc

njerry191@cloudshell:~ (extreme-clone-2654111)$ kubect1 create -f app-data.yaml

persistentvolumeclaim/app-data created

3. View the pvc

4. Let's see what has changed in the pv we had initially created.

Our status has now changed from available to bound.

5. Create a new pod named myapp with image nginx that will be used to Mount the Persistent Volume Claim with the path /var/app/config.

Mounting a Claim

apiVersion: v1

kind: Pod

metadata:

creationTimestamp: null

name: app-data

spec:

volumes:

- name:congigpvc

persistenVolumeClaim:

claimName: app-data

containers:

- image: nginx

name: app

volumeMounts:

- mountPath: '/srv/app-data '

name: configpvc

solution

kubectl run busybox --image=busybox -it --rm --restart=Never --

/bin/sh -c 'echo hello world'

kubectl get po # You shouldn't see pod with the name 'busybox'

Task Summary

SSH into cka000060

Add the Argo CD Helm repo named argo

Generate a manifest (~/argo-helm.yaml) for Argo CD version 7.7.3

Target namespace: argocd

Do not install CRDs

Just generate, don't install

Step-by-Step Solution

1 SSH into the correct host

ssh cka000060

Required --- skipping this = zero score

2 Add the Argo CD Helm repository

helm repo add argo https://argoproj.github.io/argo-helm

helm repo update

This adds the official Argo Helm chart source.

3 Generate Argo CD Helm chart template (version 7.7.3)

Use the helm template command to generate a manifest and write it to ~/argo-helm.yaml.

helm template argocd argo/argo-cd \

--version 7.7.3 \

--namespace argocd \

--set crds.install=false \

> ~/argo-helm.yaml

argocd Release name (can be anything; here it's same as the namespace)

--set crds.install=false Disables CRD installation

> ~/argo-helm.yaml Save to required file

4 Verify the generated file (optional but smart)

head ~/argo-helm.yaml

Check that it contains valid Kubernetes YAML and does not include CRDs.

Final Command Summary

ssh cka000060

helm repo add argo https://argoproj.github.io/argo-helm

helm repo update

helm template argocd argo/argo-cd \

--version 7.7.3 \

--namespace argocd \

--set crds.install=false \

> ~/argo-helm.yaml

head ~/argo-helm.yaml # Optional verification