CKA ConfigMaps and Secrets

Question 1

Which kubectl command creates a ConfigMap named 'app-config' with a literal key-value pair 'ENV=production'?

Accepted Answer

kubectl create configmap app-config --from-literal=ENV=production

Answer

The --from-literal flag is the correct way to pass key=value pairs directly on the command line when creating a ConfigMap.

Question 2

How do you expose all key-value pairs from a ConfigMap named 'app-config' as environment variables in a Pod?

Accepted Answer

Use envFrom with configMapRef specifying the ConfigMap name

Answer

The envFrom field with configMapRef injects all ConfigMap keys as environment variables at once, without listing them individually.

Question 3

A ConfigMap is mounted as a volume in a Pod. After the ConfigMap is updated, what happens to the files inside the running Pod?

Accepted Answer

The files are eventually updated automatically by the kubelet

Answer

When a ConfigMap is mounted as a volume, the kubelet periodically syncs the projected files, so changes propagate eventually without a Pod restart.

Question 4

Which kubectl command creates a ConfigMap from all files in a directory named 'configs/'?

Accepted Answer

kubectl create configmap my-config --from-file=configs/

Answer

The --from-file flag accepts either a single file path or a directory path; when given a directory, it creates one key per file.

Question 5

What is the maximum data size allowed in a single Kubernetes ConfigMap?

Accepted Answer

1 MiB

Answer

Kubernetes enforces a 1 MiB (1,048,576 byte) limit on ConfigMap data to avoid overwhelming the etcd storage backend.

(CKA) Certified Kubernetes Administrator Practice Test