CKAD Study & Exam Tips

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Agenda

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10 mins

10 mins

10 mins

Exam Tips

Study Tips

Practical Examples

Q&A Session / Discussion

15 mins

Special thanks

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https://community.cncf.io/manly

https://kubernetes.io/docs/contribute/participate

SIG Docs

slack.cncf.io

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slack.k8s.io

Exam Tips - Why sit the exam

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As one of the highest velocity projects in the history of open source, Kubernetes use is exploding. The Cloud Native Computing Foundation is committed to growing the community of Kubernetes-knowledgeable application developers, thereby enabling continued growth across the broad set of organizations using the technology.

Certification is a key step in that process, allowing certified application developers to quickly establish their credibility and value in the job market, and also allowing companies to more quickly hire high-quality teams to support their growth.

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Exam Tips - Exam Curriculum

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• 13% – Core Concepts
• 18% – Configuration
• 10% – Multi-Container Pods
• 18% – Observability
• 20% – Pod Design
• 13% – Services & Networking
• 8% – State Persistence

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CKAD Certificate

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Exam Tips

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Exam Tips - Booking your exam

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To book goto: https://www.cncf.io/certification/ckad

• Book exam straight away to set your goal

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• Free reschedule as many times as you want 24 hours in advance

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• Price is in US dollars

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• One free retake

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Exam Tips - Discount Codes

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https://events.linuxfoundation.org/kubecon-cloudnativecon-europe/register

Exam Day

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Exam

Questions

Exam Tips

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• You can start the exam 15 minutes before the scheduled time, this is the amount of time it will take to talk to the proctor.
• Make sure that your room is clean on exam day, they will ask you to walk around the room with your camera
• Nothing to be on the walls
• Drinks need to be in a clear glass, toilet breaks allowed.
• Don’t talk during the exam
• Take note of how to copy and paste

Exam Tips

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• There is a notepad you can use in the portal
• The exam consists of 15-20 performance based tasks
• Each question has a weight eg 5% skip hard ones and flag them for later
• Straight away use sudo -i to assume elevated privileges to make things easier. If you want to get out type exit or su student
• Use “ssh <Node Name>” to get into the node, remember which node you are in so you don't get confused
• Always copy pod names etc instead of typing out to avoid spelling mistakes
• Use imperative commands over YAML

Exam Tips - Naming YAML files

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When generating YAML files, name them with the question number

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Example

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1.yaml

1-svc.yaml

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kubectl run example bradmccoydev/test:latest -o yaml > 1.yaml

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cp 1.yaml 1a.yaml (backup if required)

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kubectl create -f 1.yaml

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Exam Tips - alias k=kubectl

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alias k=kubectl

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Use this so you don’t have to keep typing kubectl all the time

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Eg.

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alias k=kubectl

k run nginx --image=nginx

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Exam Tips

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Make sure you are in the right cluster, and the right namespace as specified in the question, to avoid deploying to the wrong namespace when using YAML to create resources specify it in the metadata in case you forget.

Exam Tips - kubectl api-resources

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kubectl api-resources to get names/short names eg. kubectl get svc

Exam Tips - Reverse Search (Ctrl + r)

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Exam Tips - Watch command

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Make use of the watch command when checking if deployments worked etc it will execute the command every 2 seconds until you ctrl + c eg watch kubectl get pods

Exam Tips - kubectl -h command

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Use the -h for help! kubectl run -h gives some hints if you forgot imperative commands under pressure.

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Practice the -h command on other options such as kubectl create deploy -h etc

Study Tips

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Study Tips - Courses

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walidshaari/Kubernetes-Certified-Administrator.git

Study Tips - Use bookmarks!

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In the exam you are allowed to use bookmarks for the documentation so as you study and learn add bookmarks to the page in kubernetes docs.

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When you do your practice tests and practical work, refer to the bookmarks and not your notes, this will help you be fast for exam day.

Study Tips - Use bookmarks!

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Study Tips - kubectl Reference Docs

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Study Tips - VIM

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If you don’t know VIM editor learn it. You can get away with just knowing nano, by setting KUBE_EDITOR=”nano” but when you need to edit deployments etc it will default to VIM so you don’t want to risk being stuck. If you don't know VIM you are not ready for you exam.

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VIM Cheat Sheet: vim.rtorr.com

Study Tips - VIM

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There are two modes, for writing/deleting text press i, then press esc for edit mode

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To exit without saving press esc and type :q!

To exit with saving press esc and type :wq!

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To delete a line type dd

To delete more than one line type 5dd (substitute 5 for the number you want to delete)

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To Goto line 5 type 5gg (substitute 5 for the number you want to goto)

To Jump to the end of the line type $

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To search for a word eg image press esc then type /image and press enter

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To show line numbers press esc and then type :set number

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Study Tips - Basic linux commands

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If you are a developer doing this course and you are not used to linux, it is worth learning basic linux commands.

Practical Examples

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Practical Examples

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• 13% – Core Concepts
• 18% – Configuration
• 10% – Multi-Container Pods
• 18% – Observability
• 20% – Pod Design
• 13% – Services & Networking
• 8% – State Persistence

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Practical Examples - General

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Practical Examples - Core Concepts

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kubectl run -h

kubectl run nginx --image nginx --dry-run=client -o yaml > 1.yaml

kubectl run hazelcast --image=hazelcast/hazelcast --port=5701

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kubectl run hazelcast --image=hazelcast/hazelcast --env="app=hazelcast,env=prod"

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kubectl run hazelcast --image=hazelcast/hazelcast --labels="app=hazelcast,env=prod"

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kubectl run hazelcast --image=hazelcast/hazelcast --command ‘sleep 3600’

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kubectl run hazelcast --image=hazelcast/hazelcast --requests=’cpu=100m,memory=256Mi’

kubectl run hazelcast --image=hazelcast/hazelcast --limits=’cpu=200m,memory=512Mi’

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Practical Examples - Configuration

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# Config Maps (cm for short)

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kubectl create configmap myconfig --from-literal=username=brad

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kubectl get configmap myconfig -o yaml

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kubectl run test-pod --image busybox --dry-run=client -o yaml > 1.yaml

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kubectl create -f 1.yaml

apiVersion: v1

kind: Pod

metadata:

name: test-pod

spec:

containers:

- name: test-container

image: busybox

env:

# Define the environment variable

- name: USERNAME

valueFrom:

configMapKeyRef:

# The ConfigMap containing the value you want to assign to USERNAME

name: myconfig

# Specify the key associated with the value

key: username

https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#-em-configmap-em-

Practical Examples - Configuration

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# Secrets

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kubectl create secret generic mysecret --from-literal=password=123

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kubectl get secret mysecret -o yaml

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kubectl run test-pod --image busybox --dry-run=client -o yaml > 1.yaml

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kubectl create -f 1.yaml

apiVersion: v1

kind: Pod

metadata:

name: test-pod

spec:

containers:

- name: test-container

image: busybox

env:

# Define the environment variable

- name: PASSWORD

valueFrom:

secretKeyRef:

name: mysecret

key: password

https://kubernetes.io/docs/concepts/configuration/secret/

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#-em-secret-generic-em-

Practical Examples - Configuration

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# Service account

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kubectl create serviceaccount my-service-account

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kubectl get serviceaccount my-service-account

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kubectl run test-pod --image busybox --serviceaccount='my-service-account'

https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/

https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#-em-serviceaccount-em-

Practical Examples - Observability

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# Get logs from pod

kubectl logs my-pod

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# Get logs from pods with the name label myLabel

kubectl logs -l name=myLabel

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# Output logs to console

kubectl exec my-pod -c my-container -- cat /var/log.txt (multi container)

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# Go into the pod to look for the logs

kubectl -n your-namespace exec -it pod/your-pod -- /bin/sh

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# Kubectl cheatsheet

https://kubernetes.io/docs/reference/kubectl/cheatsheet

Practical Examples - Observability

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kubectl top node

kubectl top pod

Practical Examples - Pod Design

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kubectl create deployment my-dep --image=nginx --replicas=3 --port=5701

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Practical Examples - Pod Design

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# Rolling updates, and rollbacks

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kubectl set image deployment/nginx-deployment nginx=nginx:1.16.1 --record

kubectl rollout status deployment/nginx-deployment

kubectl rollout undo deployment/nginx-deployment

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# Jobs

kubectl create job my-job --image=busybox -- date

https://kubernetes.io/docs/concepts/workloads/controllers/job

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# Cronjobs

https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs

Practical Examples - Services and Networking

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# Services

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kubectl create service clusterip my-cs --tcp=5678:8080

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kubectl create service nodeport my-ns --tcp=5678:8080

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Kubectl expose deployment nginx --port=80 --target-port=8000 (--type=ClusterIP,NodePort)

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# Network policies

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https://kubernetes.io/docs/concepts/services-networking/network-policies/

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Practical Examples - State Persistence

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# Host path example

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https://kubernetes.io/docs/concepts/storage/volumes

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If you can’t find something in the documentation remember you can use the kubectl explain command

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kubectl explain pv --recursive

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kubectl explain pod --recursive

apiVersion: v1

kind: Pod

metadata:

name: test-pd

spec:

containers:

- image: k8s.gcr.io/test-webserver

name: test-container

volumeMounts:

- mountPath: /test-pd

name: test-volume

volumes:

- name: test-volume

hostPath:

# directory location on host

path: /data

# this field is optional

type: Directory

Practical Examples - State Persistence

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We will do a separate talk on this as there is alot to cover

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https://kubernetes.io/docs/tasks/configure-pod-container/configure-volume-storage

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https://kubernetes.io/docs/tasks/configure-pod-container/configure-persistent-volume-storage

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Conclusion

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Don’t be afraid to fail. I failed my first attempt but it gave me a good opportunity to see where I needed to improve, and passed on my free retake with a high score.

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Learn the basics first, you will save time in the long run, learn basic linux, learn VIM, learn kubectl well.

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If you are having trouble getting a test environment to practice with maybe your cpu, ram on your computer can’t run Kubernetes or can’t afford it, reach out to me and I will see what I can do.

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Have fun studying, and remember there is a wonderful community out there to help you!

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Important Links - https://github.com/bradmccoydev/cncf-community-manly

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https://community.cncf.io/manly

https://kubernetes.io/docs/contribute/participate

slack.cncf.io

slack.k8s.io

https://www.cncf.io/certification/ckad

https://events.linuxfoundation.org/kubecon-cloudnativecon-europe/register

vim.rtorr.com

https://itnext.io/kubernetes-journey-cka-ckad-exam-tips-ff73e4672833

https://kubernetes.io/docs/home

Links will be added to: https://github.com/bradmccoydev/cncf-community-manly

Thank You

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CC-BY License

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This presentation is licensed under a Creative Commons Attribution 4.0 International License.

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See https://creativecommons.org/licenses/by/4.0/ for more details.

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