Question

You manage a Deployment named 'billing-api' whose pods mount a ConfigMap named 'billing-config' as environment variables using envFrom. After a colleague updates several values in 'billing-config' with 'kubectl edit configmap billing-config', users report the application is still using the old configuration values. The pods are all Running and healthy. What is the correct explanation and remediation?

Accepted Answer

Environment variables from a ConfigMap are injected only at pod startup and are not updated in-place; trigger a rolling restart with 'kubectl rollout restart deployment/billing-api' so new pods pick up the updated values.

Answer

ConfigMap changes propagate to environment variables automatically within about 60 seconds; the delay indicates the kubelet sync period must be lowered on each node.

Answer

The ConfigMap must be deleted and recreated with the same name for changes to take effect; editing in place is silently ignored by the API server.

Answer

You must scale the Deployment to zero replicas and back up so the ReplicaSet re-reads the ConfigMap; a rolling restart alone will not reload environment values.