Label-based filtering with kubectl in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of labels in Kubernetes?

Labels are simple key-value pairs attached to Kubernetes objects. They help organize and select groups of objects for management and filtering.

beginner

How do you list pods with a specific label using kubectl?

Use the command kubectl get pods -l key=value to list pods that have the label with the specified key and value.

intermediate

What does the command kubectl get pods -l env=prod,tier=frontend do?

It lists pods that have both labels env=prod and tier=frontend. Both conditions must be true for a pod to be shown.

intermediate

How can you filter Kubernetes objects by label existence, regardless of value?

Use kubectl get pods -l key to select pods that have the label key, no matter what its value is.

intermediate

What is the difference between -l key=value and -l 'key!=value' in kubectl?

-l key=value selects objects with that exact label value. -l 'key!=value' selects objects where the label key exists but its value is not equal to the given value.

Which kubectl command lists pods with the label app=web?

A kubectl get pods -l app=web

B kubectl get pods --filter app=web

C kubectl describe pods app=web

D kubectl get pods --label app=web

The correct syntax to filter by label is using -l key=value.

How do you select pods that have the label 'env' regardless of its value?

A kubectl get pods -l env

B kubectl get pods -l env=*

C kubectl get pods -l env!=null

D kubectl get pods --env

Using -l env selects pods that have the label key 'env' no matter the value.

What does kubectl get pods -l 'tier!=backend' do?

A Selects all pods

B Selects pods without the label 'tier'

C Selects pods where 'tier' label equals 'backend'

D Selects pods where 'tier' label exists and is not 'backend'

The != operator filters pods where the label exists but its value is not 'backend'.

How to filter pods with labels env=prod and tier=frontend at the same time?

A kubectl get pods --label env=prod --label tier=frontend

B kubectl get pods -l env=prod,tier=frontend

C kubectl get pods -l env=prod tier=frontend

D kubectl get pods -l env=prod|tier=frontend

Multiple labels are combined with commas in the -l option.

Which command shows all pods without filtering by label?

A kubectl get pods -l '*'

B kubectl get pods -l

C kubectl get pods

D kubectl get pods --all-labels

Running kubectl get pods without -l shows all pods.

Explain how to use kubectl to filter Kubernetes objects by labels. Include examples of filtering by single label, multiple labels, and label existence.

Think about how labels help select groups of objects.

Describe the difference between filtering with 'key=value' and 'key!=value' in kubectl label selectors.

Consider how the != operator changes the selection.