Linux Foundation CKAD Online Practice Questions and Exam Preparation

Linux Foundation CKAD Online Questions & Answers

• Question 1:

  CORRECT TEXT

  

  Context

  You sometimes need to observe a pod's logs, and write those logs to a file for further analysis.

  Task

  Please complete the following;

  1. Deploy the counter pod to the cluster using the provided YAMLspec file at /opt/KDOB00201/counter.yaml

  2. Retrieve all currently available application logs from the running pod and store them in the file /opt/KDOB0020l/log_Output.txt, which has already been created

  A. Please check explanations
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• Question 2:

  CORRECT TEXT

  

  Context

  You have been tasked with scaling an existing deployment for availability, and creating a service to expose the deployment within your infrastructure.

  Task

  Start with the deployment named kdsn00101-deployment which has already been deployed to the namespace kdsn00101. Edit it to:

  1. Add the func=webFrontEnd key/value label to the pod template metadata to identify the pod for the service definition

  2. Have 4 replicas

  Next, create and deploy in namespace kdsn00l01 a service that accomplishes the following:

  1. Exposes the service on TCP port 8080

  2. is mapped to me pods defined by the specification of kdsn00l01-deployment

  3. Is of type NodePort

  4. Has a name of cherry

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• Question 3:

  CORRECT TEXT

  

  Context

  As a Kubernetes application developer you will often find yourself needing to update a running application.

  Task

  Please complete the following:

  1. Update the app deployment in the kdpd00202 namespace with a maxSurge of 5% and a maxUnavailable of 2%

  2. Perform a rolling update of the web1 deployment, changing the Ifccncf/ngmx image version to 1.13

  3. Roll back the app deployment to the previous version

  A. Please check explanations
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• Question 4:

  CORRECT TEXT

  

  Context

  A pod is running on the cluster but it is not responding.

  Task

  The desired behavior is to have Kubemetes restart the pod when an endpoint returns an HTTP 500 on the /healthz endpoint. The service, probe-pod, should never send traffic to the pod while it is failing. Please complete the following:

  1. The application has an endpoint, /started, that will indicate if it can accept traffic by returning an HTTP 200. If the endpoint returns an HTTP 500, the application has not yet finished initialization.

  2. The application has another endpoint /healthz that will indicate if the application is still working as expected by returning an HTTP 200. If the endpoint returns an HTTP 500 the application is no longer responsive.

  3. Configure the probe-pod pod provided to use these endpoints

  4. The probes should use port 8080

  A. Please check explanations
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  ---

  apiVersion: v1

  kind: Pod

  metadata:

  labels:

  test: liveness

  name: liveness-exec

  spec:

  containers:

  -name: liveness

  image: k8s.gcr.io/busybox

  args:

  -/bin/sh

  - -c

  - touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 600 livenessProbe:

  exec:

  command:

  -cat

  -/tmp/healthy

  initialDelaySeconds: 5

  periodSeconds: 5

  In the configuration file, you can see that the Pod has a single Container. The periodSeconds field specifies that the kubelet should perform a liveness probe every 5 seconds. The initialDelaySeconds field tells the kubelet that it should wait 5

  seconds before performing the first probe. To perform a probe, the kubelet executes the command cat /tmp/healthy in the target container. If the command succeeds, it returns 0, and the kubelet considers the container to be alive and healthy.

  If the command returns a non-zero value, the kubelet kills the container and restarts it.

  When the container starts, it executes this command:

  /bin/sh -c "touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 600" For the first 30 seconds of the container's life, there is a /tmp/healthy file. So during the first 30 seconds, the command cat /tmp/healthy returns a success code. After 30

  seconds, cat /tmp/healthy returns a failure code.

  Create the Pod:

  kubectl apply -f https://k8s.io/examples/pods/probe/exec-liveness.yaml Within 30 seconds, view the Pod events:

  kubectl describe pod liveness-exec

  The output indicates that no liveness probes have failed yet:

  FirstSeen LastSeen Count From SubobjectPath Type Reason Message --------- -------- ----- ---- ------------- -------- ------ ------- 24s 24s 1 {default-scheduler } Normal Scheduled Successfully assigned liveness-exec to worker0

  23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Pulling pulling image "k8s.gcr.io/busybox"

  23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Pulled Successfully pulled image "k8s.gcr.io/busybox"

  23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Created Created container with docker id 86849c15382e; Security:[seccomp=unconfined] 23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Started Started container

  with docker id 86849c15382e

  After 35 seconds, view the Pod events again:

  kubectl describe pod liveness-exec

  At the bottom of the output, there are messages indicating that the liveness probes have failed, and the containers have been killed and recreated. FirstSeen LastSeen Count From SubobjectPath Type Reason Message --------- -------- ----- ---------------- -------- ------ ------- 37s 37s 1 {default-scheduler } Normal Scheduled Successfully assigned liveness-exec to worker0

  36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Pulling pulling image "k8s.gcr.io/busybox"

  36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Pulled Successfully pulled image "k8s.gcr.io/busybox"

  36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Created Created container with docker id 86849c15382e; Security:[seccomp=unconfined] 36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Started Started container

  with docker id 86849c15382e

  2s 2s 1 {kubelet worker0} spec.containers{liveness} Warning Unhealthy Liveness probe failed: cat: can't open '/tmp/healthy': No such file or directory Wait another 30 seconds, and verify that the container has been restarted:

  kubectl get pod liveness-exec

  The output shows that RESTARTS has been incremented:

  NAME READY STATUS RESTARTS AGE

  liveness-exec 1/1 Running 1 1m

• Question 5:

  CORRECT TEXT

  

  Task:

  

  A. Please check explanations
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• Question 6:

  CORRECT TEXT

  

  Task:

  A Dockerfile has been prepared at -/human-stork/build/Dockerfile

  

  A. Please check explanations
  B. Place Holder
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• Question 7:

  CORRECT TEXT

  

  Task:

  Update the Pod ckad00018-newpod in the ckad00018 namespace to use a NetworkPolicy allowing the Pod to send and receive traffic only to and from the pods web and db

  

  A. Please check explanations
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• Question 8:

  CORRECT TEXT

  

  Context

  A project that you are working on has a requirement for persistent data to be available.

  Task

  To facilitate this, perform the following tasks:

  1. Create a file on node sk8s-node-0 at /opt/KDSP00101/data/index.html with the content Acct=Finance

  2. Create a PersistentVolume named task-pv-volume using hostPath and allocate 1Gi to it, specifying that the volume is at /opt/KDSP00101/data on the cluster's node.

  The configuration should specify the access mode of ReadWriteOnce. It should define the StorageClass name exam for the PersistentVolume, which will be used to bind PersistentVolumeClaim requests to this PersistenetVolume.

  1. Create a PefsissentVolumeClaim named task-pv-claim that requests a volume of at least 100Mi and specifies an access mode of ReadWriteOnce

  2. Create a pod that uses the PersistentVolmeClaim as a volume with a label app: my- storage-app mounting the resulting volume to a mountPath /usr/share/nginx/html inside the pod

  

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• Question 9:

  CORRECT TEXT

  

  Context

  A user has reported an application is unreachable due to a failing livenessProbe .

  Task

  Perform the following tasks:

  Find the broken pod and store its name and namespace to /opt/KDOB00401/broken.txt in the format:

  

  The output file has already been created

  1. Store the associated error events to a file /opt/KDOB00401/error.txt, The output file has already been created. You will need to use the -o wide output specifier with your command

  2. Fix the issue.

  

  A. Please check explanations
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  Create the Pod: kubectl create -f http://k8s.io/docs/tasks/configure-pod-container/exec-liveness.yaml Within 30 seconds, view the Pod events: kubectl describe pod liveness-exec The output indicates that no liveness probes have failed yet: FirstSeen LastSeen Count From SubobjectPath Type Reason Message --------- -------- ----- ---- ------------- -------- ------ ------- 24s 24s 1 {default-scheduler } Normal Scheduled Successfully assigned liveness-exec to worker0 23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Pulling pulling image "gcr.io/google_containers/busybox" 23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Pulled Successfully pulled image "gcr.io/google_containers/busybox" 23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Created Created container with docker id 86849c15382e; Security:[seccomp=unconfined] 23s 23s 1 {kubelet worker0} spec.containers{liveness} Normal Started Started container with docker id 86849c15382e After 35 seconds, view the Pod events again: kubectl describe pod liveness-exec At the bottom of the output, there are messages indicating that the liveness probes have failed, and the containers have been killed and recreated. FirstSeen LastSeen Count From SubobjectPath Type Reason Message --------- -------- ----- ---------------- -------- ------ ------- 37s 37s 1 {default-scheduler } Normal Scheduled Successfully assigned liveness-exec to worker0 36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Pulling pulling image "gcr.io/google_containers/busybox" 36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Pulled Successfully pulled image "gcr.io/google_containers/busybox" 36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Created Created container with docker id 86849c15382e; Security:[seccomp=unconfined] 36s 36s 1 {kubelet worker0} spec.containers{liveness} Normal Started Started container with docker id 86849c15382e 2s 2s 1 {kubelet worker0} spec.containers{liveness} Warning Unhealthy Liveness probe failed: cat: can't open '/tmp/healthy': No such file or directory Wait another 30 seconds, and verify that the Container has been restarted: kubectl get pod liveness-exec The output shows that RESTARTS has been incremented: NAME READY STATUS RESTARTS AGE liveness-exec 1/1 Running 1 m

• Question 10:

  CORRECT TEXT

  

  Task:

  Modify the existing Deployment named broker-deployment running in namespace quetzal so that its containers.

  The broker-deployment is manifest file can be found at:

  

  A. Please check explanations
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