Authentic Linux Foundation Certification Exam CKAD Questions Answers

0) SSH to the correct host

ssh ckad00044

(Optional sanity)

kubectl config current-context

kubectl get ns | grep rapid-goat

1) Inspect the Deployment and current container name

kubectl -n rapid-goat get deploy busybox

kubectl -n rapid-goat get deploy busybox -o jsonpath='{.spec.template.spec.containers[*].name}{"\n"}'

kubectl -n rapid-goat get deploy busybox -o jsonpath='{.spec.template.spec.containers[*].image}{"\n"}'

Note the current container name (likely something like busybox). We need to rename it to musl.

2) Edit the Deployment (best for renaming container)

Renaming a container is easiest with edit:

kubectl -n rapid-goat edit deploy busybox

In the editor, find:

spec:

template:

spec:

containers:

- name:

image:

Change it to:

- name: musl

image: busybox:musl

Save and exit.

3) Ensure the rollout happens and completes

kubectl -n rapid-goat rollout status deploy busybox

4) Verify the new Pod template is correct

Check the Deployment template:

kubectl -n rapid-goat get deploy busybox -o jsonpath='{.spec.template.spec.containers[0].name}{"\n"}{.spec.template.spec.containers[0].image}{"\n"}'

Check running Pods and the image actually used:

kubectl -n rapid-goat get pods -o wide

POD=$(kubectl -n rapid-goat get pods -l app=busybox -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || true)

If you don’t have that label selector, just pick a pod name from kubectl get pods and:

kubectl -n rapid-goat describe pod | sed -n '/Containers:/,/Conditions:/p'

To find the broken pod and store its name and namespace to /opt/KDOB00401/broken.txt, you can use the kubectl get pods command and filter the output by the status of the pod.

kubectl get pods --field-selector=status.phase=Failed -o jsonpath='{.items[*].metadata.namespace}/{.items[*].metadata.name}' > /opt/KDOB00401/broken.txt

This command will list all pods with a status of Failed and output their names and namespaces in the format /. The output is then written to the /opt/KDOB00401/broken.txt file.

To store the associated error events to a file /opt/KDOB00401/error.txt, you can use the kubectl describe command to retrieve detailed information about the pod, and the grep command to filter the output for error events.

kubectl describe pods --namespace | grep -i error -B5 -A5 > /opt/KDOB00401/error.txt

Replace and with the name and namespace of the broken pod you found in the previous step.

This command will output detailed information about the pod, including error events. The grep command filters the output for lines containing "error" and also prints 5 lines before and after the match.

To fix the issue, you need to analyze the error events and find the root cause of the issue.

It could be that the application inside the pod is not running, the container image is not available, the pod has not enough resources, or the liveness probe configuration is incorrect.

Once you have identified the cause, you can take appropriate action, such as restarting the application, updating the container image, increasing the resources, or modifying the liveness probe configuration.

After fixing the issue, you can use the kubectl get pods command to check the status of the pod and ensure

Solution:

To update the nginxsvc service to serve on port 5050, you will need to edit the service's definition yaml file. You can use the kubectl edit command to edit the service in place.

kubectl edit svc nginxsvc

This will open the service definition yaml file in your default editor. Change the targetPort of the service to 5050 and save the file.

To add an HAproxy container named haproxy bound to port 90 to the poller pod, you will need to edit the pod's definition yaml file located at /opt/KDMC00101/poller.yaml.

You can add a new container to the pod's definition yaml file, with the following configuration:

containers:

- name: haproxy

image: haproxy

ports:

- containerPort: 90

volumeMounts:

- name: haproxy-config

mountPath: /usr/local/etc/haproxy/haproxy.cfg

subPath: haproxy.cfg

args: ["haproxy", "-f", "/usr/local/etc/haproxy/haproxy.cfg"]

This will add the HAproxy container to the pod and configure it to listen on port 90. It will also mount the ConfigMap haproxy-config to the container, so that haproxy.cfg is available at /usr/local/etc/haproxy/haproxy.cfg.

To inject the configuration located at /opt/KDMC00101/haproxy.cfg to the container, you will need to create a ConfigMap using the following command:

kubectl create configmap haproxy-config --from-file=/opt/KDMC00101/haproxy.cfg

You will also need to update the args of the poller container so that it connects to localhost instead of nginxsvc. You can do this by editing the pod's definition yaml file and changing the args field to args: ["poller","--host=localhost"].

Once you have made these changes, you can deploy the updated pod to the cluster by running the following command:

kubectl apply -f /opt/KDMC00101/poller.yaml

This will deploy the enhanced pod with the HAproxy container to the cluster. The HAproxy container will listen on port 90 and proxy connections to the nginxsvc service on port 5050. The poller container will connect to localhost instead of nginxsvc, so that the connection is correctly proxied to the new service endpoint.

Please note that, this is a basic example and you may need to tweak the haproxy.cfg file and the args based on your use case.