Work fast in the CKA exam

Dit deel is nog niet vertaald. Je ziet de Engelse tekst.

$ als gewone gebruiker# als root (of met sudo)

Set up the terminal once

A few aliases and variables at the start pay back in every task.

$alias k=kubectl
$complete -o default -F __start_kubectl k
$export do="--dry-run=client -o yaml"
$export now="--force --grace-period 0"
$echo 'set ts=2 sw=2 et ai' >> ~/.vimrc
$k run tmp --image=nginx $do > pod.yaml
$k delete pod tmp $now

13.2

Use imperative commands

Most objects can be created in one line, or generated as YAML to edit.

Object	Command
Pod	`k run web --image=nginx --port=80 --labels=app=web`
Deployment	`k create deploy web --image=nginx --replicas=3`
Service	`k expose deploy web --port=80 --target-port=8080`
ConfigMap	`k create cm cfg --from-literal=k=v --from-file=f.conf`
Secret	`k create secret generic s --from-literal=pw=x`
Role / binding	`k create role r --verb=get,list --resource=pods`; `k create rolebinding …`
Job / CronJob	`k create job j --image=busybox -- echo hi`; `k create cronjob …`
Ingress	`k create ingress i --rule="host/path=svc:port"`
HPA	`k autoscale deploy web --min=2 --max=5 --cpu-percent=70`

13.3

Find things in the docs fast

kubectl explain is faster than the docs for field names; the docs search is best for full YAML examples.

$k explain pod.spec.containers.securityContext
$k explain networkpolicy.spec.ingress --recursive | head -30
$k api-resources --namespaced=true | grep -i quota

Op het werk

Bookmark nothing (not allowed), but know the doc page titles: "Network Policies", "Configure a Security Context", "Operating etcd clusters", "Upgrading kubeadm clusters", "Persistent Volumes", "Ingress".

13.4

Work through the tasks

Points per task are shown. Do quick tasks first, flag long ones, come back later.

Read the task fully; run the context command it gives.
Note the namespace — most wrong answers are in the wrong namespace.
Make it, then verify (get, describe, auth can-i, curl from a pod).
Move on after 7 – 8 minutes; come back at the end.

13.5

Practise the classic tasks

These appear in some form in almost every exam — do each one many times.

Task	Lesson
etcd backup and restore	Back up etcd
Upgrade control plane and a worker	Upgrade
Fix a NotReady node	Debug a node
RBAC for a user or service account	RBAC
NetworkPolicy between namespaces	NetworkPolicies
PVC + pod with a mount	Storage
Rollout and rollback	Workloads
Ingress or Gateway routes	Ingress
Taints, tolerations, node affinity	Scheduling
Install with Helm	Helm

Onthoud

Use killer.sh (2 sessions come with the exam) in the last two weeks. It is harder than the real exam — 60 – 70 % there is a good sign.

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