CKA — Essential kubectl Skills

Why Speed Matters

The CKA exam gives you 2 hours for 15–20 tasks. That is roughly 6–8 minutes per task. If you spend time typing long commands or writing YAML from scratch, you will run out of time. kubectl mastery and smart shortcuts are essential for passing.

Set up these shortcuts at the very start of your exam — they will save minutes on every question.

Aliases and Auto-Completion

# Set these up FIRST THING in the exam
alias k=kubectl
complete -o default -F __start_kubectl k

# Shortcuts for common operations
export do="--dry-run=client -o yaml"
export now="--force --grace-period 0"

These three lines give you:

• k instead of kubectl (saves typing on every command)
• Tab-completion for k (works like kubectl tab-complete)
• $do to generate YAML without creating resources
• $now to force-delete resources instantly

Imperative Commands

Imperative commands are faster than writing YAML from scratch. Use them to create resources quickly, then edit the YAML if needed.

Create Resources

# Create a Pod
k run nginx --image=nginx

# Create a Deployment
k create deployment web --image=nginx --replicas=3

# Create a Job
k create job backup --image=busybox -- /bin/sh -c "echo backup done"

# Create a CronJob
k create cronjob report --image=busybox --schedule="*/5 * * * *" -- /bin/sh -c "date"

# Create a Namespace
k create namespace dev

# Create a ConfigMap
k create configmap app-config --from-literal=ENV=production --from-literal=LOG_LEVEL=info

# Create a Secret
k create secret generic db-creds --from-literal=password=secret123

# Create a ServiceAccount
k create serviceaccount app-sa

# Create a ClusterRole
k create clusterrole pod-reader --verb=get,list,watch --resource=pods

# Create a ClusterRoleBinding
k create clusterrolebinding pod-reader-binding --clusterrole=pod-reader --serviceaccount=default:app-sa

Expose Resources

# Expose a Deployment as ClusterIP Service
k expose deployment web --port=80 --target-port=80

# Expose as NodePort
k expose deployment web --port=80 --target-port=80 --type=NodePort

# Create a Service for a Pod
k expose pod nginx --port=80 --name=nginx-svc

Generate YAML (Dry-Run)

# Generate Pod YAML
k run nginx --image=nginx $do > pod.yaml

# Generate Deployment YAML
k create deployment web --image=nginx --replicas=3 $do > deploy.yaml

# Generate Service YAML
k expose deployment web --port=80 $do > svc.yaml

# Edit the YAML file, then apply
vim pod.yaml
k apply -f pod.yaml

Imperative vs Declarative

Aspect	Imperative	Declarative
Speed	Faster for simple resources	Slower (write YAML first)
Complexity	Limited options	Full customization
Exam strategy	Use for simple creates	Use for complex specs
Example	k run nginx --image=nginx	k apply -f pod.yaml
Best for	Pods, Deployments, Services, ConfigMaps	Multi-container Pods, complex scheduling, volumes

Exam strategy: Use imperative commands to create simple resources. Use $do to generate YAML, then edit it for complex requirements.

Context Switching

Every CKA question specifies a cluster context. Always switch context before starting a question.

# List all contexts
k config get-contexts

# Switch to a different cluster
k config use-context cluster1

# Verify current context
k config current-context

# Set default namespace for current context
k config set-context --current --namespace=kube-system

# View current context details
k config view --minify

Warning: Forgetting to switch context is the #1 reason candidates lose marks on tasks they know how to solve. Make it a habit: read the context line, switch, then start.

Output Formatting

# Wide output (shows node, IP, etc.)
k get pods -o wide

# YAML output
k get pod nginx -o yaml

# JSON output
k get pod nginx -o json

# JSONPath — extract specific fields
k get pods -o jsonpath='{.items[*].metadata.name}'

# Custom columns
k get pods -o custom-columns=NAME:.metadata.name,STATUS:.status.phase

# Sort by creation time
k get pods --sort-by=.metadata.creationTimestamp

Debugging Commands

# Describe a resource (events, conditions)
k describe pod nginx

# View logs
k logs nginx
k logs nginx -c sidecar          # specific container
k logs nginx --previous           # previous crashed container
k logs -l app=web                 # logs by label

# Execute command in a Pod
k exec -it nginx -- /bin/sh

# Debug a node
k debug node/worker1 -it --image=busybox

# Check resource usage
k top pods
k top nodes

# Check RBAC permissions
k auth can-i create pods
k auth can-i create pods --as=dev-user
k auth can-i create pods --as=system:serviceaccount:default:app-sa

Quick Reference Table

Task	Command
Create Pod	k run nginx --image=nginx
Create Deployment	k create deploy web --image=nginx --replicas=3
Expose Service	k expose deploy web --port=80 --type=NodePort
Generate YAML	k run nginx --image=nginx $do > pod.yaml
Force delete	k delete pod nginx $now
Switch context	k config use-context cluster1
Set namespace	k config set-context --current --namespace=dev
Check permissions	k auth can-i create pods --as=dev-user
View all resources	k get all -A
Describe resource	k describe pod nginx
View logs	k logs nginx -f
Exec into Pod	k exec -it nginx -- /bin/sh

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