Prepare for the Actual Kubernetes Application Developer CKAD Exam Practice Materials Collection [Q10-Q32]

1 Mar, 2024 By admin CKAD, Linux Foundation 0 Comments

Prepare for the Actual Kubernetes Application Developer CKAD Exam Practice Materials Collection [Q10-Q32]

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Prepare for the Actual Kubernetes Application Developer CKAD Exam Practice Materials Collection

Kubernetes Application Developer Certified Official Practice Test CKAD – Mar-2024

The CKAD certification exam is designed for developers with experience in containerization and Kubernetes, looking to validate their skills and knowledge to build, deploy, and manage cloud-native applications on Kubernetes. CKAD exam evaluates the candidate’s understanding of Kubernetes architecture, Kubernetes objects, Kubernetes networking, Kubernetes storage, Kubernetes security, and Kubernetes troubleshooting. The CKAD certification is recognized globally by organizations and enterprises as a standard for Kubernetes application development expertise, making it a valuable credential for developers seeking to advance their careers in cloud computing and containerization.

To prepare for the CKAD certification exam, developers can take advantage of a range of resources offered by the Linux Foundation, including training courses, study guides, and practice exams. The Linux Foundation also offers a community forum where developers can connect with other CKAD candidates and share tips and advice on how to prepare for the exam. With the right preparation and dedication, developers can earn their CKAD certification and take their career in Kubernetes application development to the next level.

NO.10

Task:
Create a Pod named nginx resources in the existing pod resources namespace.
Specify a single container using nginx:stable image.
Specify a resource request of 300m cpus and 1G1 of memory for the Pod’s container.

NO.11 Context

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

NO.12

Task:
1) Create a secret named app-secret in the default namespace containing the following single key-value pair:
Key3: value1
2) Create a Pod named ngnix secret in the default namespace.Specify a single container using the nginx:stable image.
Add an environment variable named BEST_VARIABLE consuming the value of the secret key3.

NO.13 Refer to Exhibit.

Task
A Deployment named backend-deployment in namespace staging runs a web application on port 8081.

NO.14 Exhibit:

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

Solution:

NO.15 Context

Task:
A pod within the Deployment named buffale-deployment and in namespace gorilla is logging errors.
1) Look at the logs identify errors messages.
Find errors, including User “system:serviceaccount:gorilla:default” cannot list resource “deployment” […] in the namespace “gorilla”
2) Update the Deployment buffalo-deployment to resolve the errors in the logs of the Pod.
The buffalo-deployment ‘S manifest can be found at -/prompt/escargot/buffalo-deployment.yaml

NO.16 Context

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:
* 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.
* 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.
* Configure the probe-pod pod provided to use these endpoints
* The probes should use port 8080

NO.17 Context

Context
A container within the poller pod is hard-coded to connect the nginxsvc service on port 90 . As this port changes to 5050 an additional container needs to be added to the poller pod which adapts the container to connect to this new port. This should be realized as an ambassador container within the pod.
Task
* Update the nginxsvc service to serve on port 5050.
* Add an HAproxy container named haproxy bound to port 90 to the poller pod and deploy the enhanced pod. Use the image haproxy and inject the configuration located at /opt/KDMC00101/haproxy.cfg, with a ConfigMap named haproxy-config, mounted into the container so that haproxy.cfg is available at /usr/local/etc/haproxy/haproxy.cfg. Ensure that you update the args of the poller container to connect to localhost instead of nginxsvc so that the connection is correctly proxied to the new service endpoint. You must not modify the port of the endpoint in poller’s args . The spec file used to create the initial poller pod is available in /opt/KDMC00101/poller.yaml

NO.18 Context

Context
It is always useful to look at the resources your applications are consuming in a cluster.
Task
* From the pods running in namespace cpu-stress , write the name only of the pod that is consuming the most CPU to file /opt/KDOBG030l/pod.txt, which has already been created.

NO.19 Exhibit:

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:
* 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.
* 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.
* Configure the probe-pod pod provided to use these endpoints
* The probes should use port 8080

Solution:

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
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

Solution:

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

NO.20 Exhibit:

Task
You are required to create a pod that requests a certain amount of CPU and memory, so it gets scheduled to-a node that has those resources available.
* Create a pod named nginx-resources in the pod-resources namespace that requests a minimum of 200m CPU and 1Gi memory for its container
* The pod should use the nginx image
* The pod-resources namespace has already been created

Solution:

NO.21

Task
A deployment is falling on the cluster due to an incorrect image being specified. Locate the deployment, and fix the problem.

NO.22 Context

Context
You are asked to prepare a Canary deployment for testing a new application release.
Task:
A Service named krill-Service in the goshark namespace points to 5 pod created by the Deployment named current-krill-deployment

1) Create an identical Deployment named canary-kill-deployment, in the same namespace.
2) Modify the Deployment so that:
-A maximum number of 10 pods run in the goshawk namespace.
-40% of the krill-service ‘s traffic goes to the canary-krill-deployment pod(s)

NO.23 Refer to Exhibit.

Task:
1) First update the Deployment cka00017-deployment in the ckad00017 namespace:
*To run 2 replicas of the pod
*Add the following label on the pod:
Role userUI
2) Next, Create a NodePort Service named cherry in the ckad00017 nmespace exposing the ckad00017-deployment Deployment on TCP port 8888

NO.24 Context

Context
As a Kubernetes application developer you will often find yourself needing to update a running application.
Task
Please complete the following:
* Update the app deployment in the kdpd00202 namespace with a maxSurge of 5% and a maxUnavailable of 2%
* Perform a rolling update of the web1 deployment, changing the Ifccncf/ngmx image version to 1.13
* Roll back the app deployment to the previous version

NO.25 Refer to Exhibit.

Task:
Update the Deployment app-1 in the frontend namespace to use the existing ServiceAccount app.

NO.26

Given a container that writes a log file in format A and a container that converts log files from format A to format B, create a deployment that runs both containers such that the log files from the first container are converted by the second container, emitting logs in format B.
Task:
* Create a deployment named deployment-xyz in the default namespace, that:
*Includes a primary
lfccncf/busybox:1 container, named logger-dev
*includes a sidecar Ifccncf/fluentd:v0.12 container, named adapter-zen
*Mounts a shared volume /tmp/log on both containers, which does not persist when the pod is deleted
*Instructs the logger-dev
container to run the command

which should output logs to /tmp/log/input.log in plain text format, with example values:

* The adapter-zen sidecar container should read /tmp/log/input.log and output the data to /tmp/log/output.* in Fluentd JSON format. Note that no knowledge of Fluentd is required to complete this task: all you will need to achieve this is to create the ConfigMap from the spec file provided at /opt/KDMC00102/fluentd-configma p.yaml , and mount that ConfigMap to /fluentd/etc in the adapter-zen sidecar container See the solution below.

NO.27 Exhibit:

Context
You are tasked to create a secret and consume the secret in a pod using environment variables as follow:
Task
* Create a secret named another-secret with a key/value pair; key1/value4
* Start an nginx pod named nginx-secret using container image nginx, and add an environment variable exposing the value of the secret key key 1, using COOL_VARIABLE as the name for the environment variable inside the pod

Solution:

NO.28 Refer to Exhibit.

Task:
A Dockerfile has been prepared at -/human-stork/build/Dockerfile
1) Using the prepared Dockerfile, build a container image with the name macque and lag 3.0. You may install and use the tool of your choice.

2) Using the tool of your choice export the built container image in OC-format and store it at -/human stork/macque 3.0 tar

NO.29 Refer to Exhibit.

Task
Create a new deployment for running.nginx with the following parameters;
* Run the deployment in the kdpd00201 namespace. The namespace has already been created
* Name the deployment frontend and configure with 4 replicas
* Configure the pod with a container image of lfccncf/nginx:1.13.7
* Set an environment variable of NGINX__PORT=8080 and also expose that port for the container above

NO.30 Context
Anytime a team needs to run a container on Kubernetes they will need to define a pod within which to run the container.
Task
Please complete the following:
* Create a YAML formatted pod manifest
/opt/KDPD00101/podl.yml to create a pod named app1 that runs a container named app1cont using image Ifccncf/arg-output with these command line arguments: -lines 56 -F
* Create the pod with the kubect1 command using the YAML file created in the previous step
* When the pod is running display summary data about the pod in JSON format using the kubect1 command and redirect the output to a file named /opt/KDPD00101/out1.json
* All of the files you need to work with have been created, empty, for your convenience

NO.31 Exhibit:

Context
Your application’s namespace requires a specific service account to be used.
Task
Update the app-a deployment in the production namespace to run as the restrictedservice service account. The service account has already been created.

Solution:

NO.32 Context

Task:
A Dockerfile has been prepared at -/human-stork/build/Dockerfile
1) Using the prepared Dockerfile, build a container image with the name macque and lag 3.0. You may install and use the tool of your choice.

2) Using the tool of your choice export the built container image in OC-format and store it at -/human stork/macque 3.0 tar