ConfigMaps in Kubernetes

A ConfigMap is an API object used to store non-confidential data in key-value pairs. Pods can consume ConfigMaps as environment variables, command-line arguments, or as configuration files in a volume.

Table of Contents

• ConfigMaps in Kubernetes
  • Table of Contents
  • Why Use a ConfigMap?
  • Creating ConfigMaps
  • Using ConfigMaps
  • ConfigMap Limitations
  • Cheat Sheets

Why Use a ConfigMap?

ConfigMaps allow you to decouple configuration artifacts from image content to keep containerized applications portable. This separation of data from code allows your application to be deployed alongside its configuration.

Creating ConfigMaps

You can create ConfigMaps using the kubectl create configmap command, kubectl apply -f with a ConfigMap YAML, or via the Kubernetes API.

Using ConfigMaps

You can use a ConfigMap in a Pod spec wherever environment variables are called for, or as a file in a Pod’s volume.

ConfigMap Limitations

ConfigMaps are not suitable for storing sensitive information. Use a Secret for that.

Cheat Sheets

Name	Command
Create a new ConfigMap	kubectl create configmap <NAME> --from-literal=key=value
Create a new ConfigMap from a file	kubectl create configmap <NAME> --from-file=path/to/file
Get ConfigMaps	kubectl get configmaps
Describe a ConfigMap	kubectl describe configmap <NAME>
Delete a ConfigMap	kubectl delete configmap <NAME>
Get a ConfigMap’s data field	kubectl get configmap <NAME> -o jsonpath='{.data}'
Get a ConfigMap’s specific data field	kubectl get configmap <NAME> -o jsonpath='{.data.<KEY>}'
Patch a ConfigMap	kubectl patch configmap <NAME> -p '{"data":{"key":"new value"}}'
Replace a ConfigMap	kubectl replace -f configmap.yaml