CKA kubectl explain Workflow Cheat Sheet

Exam Setup

alias k=kubectl

source <(kubectl completion bash)

complete -F __start_kubectl k

export do='--dry-run=client -o yaml'

Generate YAML Fast

k run nginx \
--image=nginx \
$do > pod.yaml

k create deployment web \
--image=nginx \
$do > deploy.yaml

k expose deployment web \
--port=80 \
--target-port=80 \
$do > svc.yaml

Basic Explain Workflow

kubectl explain pod

apiVersion
kind
metadata
spec
status

kubectl explain pod.spec

kubectl explain pod.spec.containers

kubectl explain pod.spec.containers.image

NetworkPolicy Workflow

kubectl explain networkpolicy.spec

kubectl explain networkpolicy.spec.ingress

kubectl explain networkpolicy.spec.ingress.from

kubectl explain networkpolicy.spec.ingress.ports

• Allow only namespace X
• Allow only pod Y
• Allow only port 80
• Deny everything else

PVC Workflow

kubectl explain pvc.spec

kubectl explain pvc.spec.resources

kubectl explain pvc.spec.resources.requests

• PersistentVolumeClaims
• Storage requests
• Access Modes
• Storage Classes

Tolerations Workflow

kubectl explain pod.spec.tolerations

key
operator
value
effect
tolerationSeconds

• Taints
• Tolerations
• Scheduling questions

Ingress Workflow

kubectl explain ingress.spec.rules

kubectl explain ingress.spec.rules.http

kubectl explain ingress.spec.rules.http.paths

kubectl explain ingress.spec.rules.http.paths.backend

Recursive Mode (Super Useful)

kubectl explain pod --recursive

KIND: Pod

apiVersion
kind
metadata
  name
  namespace

spec
  containers
    image
    ports

CKA Troubleshooting Commands

kubectl get pods

kubectl describe pod 

kubectl logs 

kubectl exec -it  -- sh

Most Common CKA Keywords

• hostPath → PV
• persistent storage → PV/PVC
• only allow → NetworkPolicy
• routing traffic → Ingress
• schedule pod → nodeSelector
• prevent scheduling → taint
• allow taint → toleration
• configuration → ConfigMap
• sensitive data → Secret
• external access → NodePort
• one-time task → Job
• recurring task → CronJob
• cluster restore → ETCD snapshot

CKA Winning Formula

1. Generate YAML

kubectl create ... --dry-run=client -o yaml

2. Edit YAML

vi file.yaml

3. Discover fields

kubectl explain ...

4. Apply

kubectl apply -f file.yaml

You do not need to memorize every YAML field. You only need to know how to quickly find it.