Question

A developer stores an application's configuration in a ConfigMap and mounts it into a Pod as environment variables using the envFrom field. After updating a value in the ConfigMap with kubectl edit, they notice the running Pod still uses the old configuration value. What is the most likely reason?

Accepted Answer

Environment variables injected from a ConfigMap are set only at container startup and are not updated in a running container.

Answer

The ConfigMap change was saved to etcd but never propagated to the API server, so the Pod cannot see it.

Answer

ConfigMaps are immutable by default, so the kubectl edit command silently failed to apply the change.

Answer

The Pod must be labeled with configmap-reload=true for environment variables to refresh automatically.