Creating ConfigMaps from literals in Kubernetes - Quick Revision & Summary

Recall & Review

beginner

What is a ConfigMap in Kubernetes?

A ConfigMap is a Kubernetes object used to store non-confidential configuration data in key-value pairs. It helps separate configuration from container images, making apps easier to manage.

beginner

How do you create a ConfigMap from literals using kubectl?

Use the command: <br>kubectl create configmap <name> --from-literal=key1=value1 --from-literal=key2=value2<br>This creates a ConfigMap with keys and values directly from the command line.

beginner

Why use literals to create ConfigMaps instead of files?

Literals let you quickly create small ConfigMaps without needing separate files. It's like writing a quick note instead of printing a whole page.

beginner

What command shows the data inside a ConfigMap?

Use kubectl describe configmap <name> or kubectl get configmap <name> -o yaml to see the stored key-value pairs.

intermediate

Can you update a ConfigMap created from literals directly with kubectl?

No, you cannot update literals directly. You must delete and recreate the ConfigMap or use kubectl edit configmap <name> to modify it.

Which command creates a ConfigMap named 'app-config' with a key 'mode' set to 'production' using literals?

A kubectl create configmap app-config --from-literal=mode=production

B kubectl create configmap app-config --from-file=mode=production

C kubectl apply configmap app-config --from-literal=mode=production

D kubectl configmap create app-config --literal=mode=production

The correct syntax to create a ConfigMap from literals is 'kubectl create configmap --from-literal=key=value'.

What does the command 'kubectl create configmap my-config --from-literal=env=dev --from-literal=debug=true' do?

A Creates a file named 'my-config' with environment variables

B Updates an existing ConfigMap named 'my-config'

C Creates a ConfigMap named 'my-config' with keys 'env' and 'debug' set to 'dev' and 'true'

D Deletes the ConfigMap named 'my-config'

This command creates a new ConfigMap with two key-value pairs from literals.

How can you view the contents of a ConfigMap named 'settings'?

A kubectl get configmap settings -o yaml

B kubectl create configmap settings

C kubectl delete configmap settings

D kubectl run configmap settings

The command 'kubectl get configmap -o yaml' shows the full details of the ConfigMap.

If you want to add a new key-value pair to an existing ConfigMap created from literals, what should you do?

A ConfigMaps cannot be changed once created

B Use 'kubectl create configmap' again with the new key

C Use 'kubectl add literal' command

D Delete and recreate the ConfigMap with all key-value pairs including the new one

ConfigMaps created from literals cannot be updated directly; you must recreate them with all desired data.

What is the main benefit of using ConfigMaps in Kubernetes?

A Runs containers faster

B Separates configuration from application code

C Stores sensitive passwords securely

D Manages network policies

ConfigMaps help keep configuration data separate from container images, making apps easier to manage and update.

Explain how to create a ConfigMap from literals and why you might choose this method.

Think about creating small config data directly from the command line.

Describe how to check the contents of a ConfigMap and how to update it if needed.

Viewing is easy, but updating literals requires a special approach.