When checking an application's configuration, I often want to see what is actually stored in its ConfigMap. You can get that straight from the terminal.

First, list the ConfigMaps in your namespace:

kubectl get configmaps -n staging

Then view the one you're interested in as YAML:

kubectl get configmap web-config -n staging -o yaml

Replace web-config and staging with your own values. Here's an illustrative response with some metadata omitted:

apiVersion: v1
kind: ConfigMap
metadata:
  name: web-config
  namespace: staging
data:
  APP_ENV: staging
  LOG_LEVEL: info
  API_BASE_URL: https://api.example.com

If you only need a single value, JSONPath keeps the output small:

kubectl get configmap web-config -n staging -o jsonpath='{.data.LOG_LEVEL}{"\n"}'

For the example above, that prints:

info

One thing to remember: this shows the ConfigMap stored in Kubernetes. It doesn't prove that the application is already using its latest values.

Values injected as environment variables require a pod restart to pick up changes. Mounted ConfigMap files generally update eventually, but subPath mounts don't receive those updates, and the application may still need to reload the file. The ConfigMap documentation explains these differences.

ConfigMaps are intended for non-confidential configuration. Passwords and tokens belong in Secrets or your existing secrets-management system.

Hope you found this useful!