CKA Certified Kubernetes Administrator (CKA) Program Questions and Answers

Solution:

kubectl logs bar | grep 'unable-to-access-website' > /opt/KUTR00101/bar

cat /opt/KUTR00101/bar

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: PersistentVolumeapiVersion: v1metadata: name:app-dataspec: 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.

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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: PersistentVolumeapiVersion: v1metadata: 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

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

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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: v1kind: Podmetadata: creationTimestamp: null name: app-dataspec: volumes: - name:congigpvc persistenVolumeClaim: claimName: app-data containers: - image: nginx name: app volumeMounts: - mountPath: "/srv/app-data " name: configpvc

solution

F:\Work\Data Entry Work\Data Entry\20200827\CKA\1 B.JPG

F:\Work\Data Entry Work\Data Entry\20200827\CKA\1 C.JPG

solution

F:\Work\Data Entry Work\Data Entry\20200827\CKA\15 B.JPG

F:\Work\Data Entry Work\Data Entry\20200827\CKA\15 C.JPG

Kubect1 get po -o wide

Using JsonPath

kubect1 get pods -o=jsonpath='{range

items[*]}{.metadata.name}{"\t"}{.status.podIP}{"\n"}{end}'

kubectl run busybox --image=busybox --restart=Never –-rm -it -- env > envpod.yaml

kubectl run busybox --image=busybox --restart=Never -- /bin/sh -c

"sleep 3600"