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CKAD Tips & Tricks

Create an alias for kubectl

No need to type kubectl every single time.

alias kk=kubectl

Kubectl run is your friend

There's no way you'll have time to type all of these up in the exam, so use a base template.

Pod yaml

kk run p1 --image=nginx --restart=Never --dry-run=client -o yaml > p1.yaml

Deploy yaml

kk run d1 --image=nginx --dry-run=client -o yaml > d1.yaml

Job yaml

kk run j1 --image=nginx --restart=OnFailure --dry-run -o yaml > j1.yaml

CronJob yaml

kk run cj1 --image=nginx --restart=OnFailure --schedule="*/1 * * * * " \
--dry-run -o yaml > cj1.yaml

Grep for events to describe pod details

kk describe pod <pod-name> | grep -i events -A 10

The -A option essentially means 'after,' so you're saying give me the search results that start with 'events' and then the next 10 lines too. Piping through with tail works fine as well, but this option is a bit more precise

Find all the kubectl shortcuts

kk api-resources | grep -i persistentvolumeclaim

This gets you the following response

persistentvolumeclaims     pvc   true    PersistentVolumeClaim

Api-resources gives you the supported api resources (duh), but it also gives you the shortcuts for each resource. Which would you rather do?

kubectl get persistentvolumeclaim

kk get pvc

Find the fields for supported resources

Need to know about the NodeSelector field in a pod? Check the specs with explain.

kk explain pod.spec.nodeSelector

Note that it is cap sensitive, so your best bet is to first pipe it through to a case insensitive grep and see if you're in the right spot

kk explain pod.spec | grep -i nodeselector

Inside these explanations, there's generally a link to the documentation that is necessary for greater understanding.

Strictly speaking, it may be faster to just use the k8s docs over this method if you're less familiar with some of the more niche specs.

Cut out the (sometimes) crap in —help arguments options

When typing in -h or —help, you get A LOT of options info populated, where generally you may just want to see some examples of the object being used. To mitigate this, use head to only see the examples. Generally, the first 25-30 lines are strictly example based.

kk annotate --help | head -30

Specificity matters

It's possible to declare details at both the pod level and then the container level. For instance, securityContext can be set in both. More granularity will override other specifics declared in the YAML.

Here is an example with securityContext:

kk explain pod.spec.securityContext

kk explain pod.spec.containers.securityContext

In this example, if I set runAsUser in both the Pod specs and container specs, the container classification would override the pod specs.

Get to know Vim

The test is command line based, so you'll need to know to use Vim or another text editor. Without it, you'll be very strapped for time.

Here are some potential keys in Vim that will prove useful (I'm gonna assume you at least know how to exit the editor and navigate without the arrows ;) Note, these are case sensitive

Shift + A - go to the end of the current row (insert mode)

Shift + C - delete everything after the cursor (insert mode)

Shift + I - go to the first letter on the current row (insert mode)

Shift + G - go to the last row of data in the file

/Pod - find any instances of Pod in the file

e - jump to the end of the next word

w - jump to the start of the next word

:25 - go to the 25th row in the file

If you REALLY hate Vim, change the editor stat!

export KUBECTL_EDITOR="nano"