Kubernetes CKA sample exam question 61 with answer

Question
Create a Pod named multi-container-playground in Namespace default with three containers named c1, c2 and c3. There should be a volume attached to that Pod and mounted into every container, but the volume shoudn't be persisted or shared with other Pods.
Container c1 should be of image nginx:1.17.6-alpine and have the name where its Pod is running available as environment variable MY_NODE_NAME.
Container c2 should be of image busybox:1.31.1 and write the output of the date command every second on the shared volume into the file date.log. You can use:

while true; do date >> /log/date.log; sleep 1; done

for this.
Container c3 should be of image busybox:1.31.1 and constantly send the content of the file date.log from the shared volume to stdout. You can use:

tail -f /log/date.log

for this.
Check the logs of the container c3 to confirm correct setup.

Answer
Generate initial manifest:

kubectl run multi-container-playground --image=nginx:1.17.6-alpine --dry-run=client -o yaml

Adjust the manufest:

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: multi-container-playground
  name: multi-container-playground
spec:
  containers:
  - image: nginx:1.17.6-alpine
    name: c1
    env:
    - name: MY_NODE_NAME
      valueFrom:
        fieldRef:
          fieldPath: spec.nodeName
    volumeMounts:
    - mountPath: /log
      name: log-volume
  - image: busybox:1.31.1
    name: c2
    command: ["/bin/sh", "-c", "while true; do date >> /log/date.log; sleep 1; done"]
    volumeMounts:
    - mountPath: /log
      name: log-volume
  - image: busybox:1.31.1
    name: c3
    command: ["/bin/sh", "-c", "tail -f /log/date.log"]
    volumeMounts:
    - mountPath: /log
      name: log-volume
  volumes:
  - name: log-volume
    emptyDir: {}

Apply:

kubectl apply -f pod.yaml

Verify:

kubectl exec -it multi-container-playground -c c1 -- env
kubectl logs -f multi-container-playground -c c3