Live update of Kubernetes container environment variable derived from configMapRef

5/30/2019

For one of my containers inside a pod I set some of the environment variables using envFrom:

envFrom:
  - configMapRef:
      name: my-config-map

Experimenting, it seems that updating the ConfigMap does not change the value of the corresponding environment value in the container.

Is there some way to force the update of the environment variable when setting them using configMapRef? If not, where is this limitation explicitly documented?

-- rlandster
configmap
environment-variables
kubernetes

1 Answer

5/30/2019

The environment variables are set when the container is starting so there is no possible way to update those environment variables. You will need to restart Pod so it that reads again the ConfigMap values and sets the environment for the new created container.

You can do this automatically with some tools out there, like reloader, which will

watch changes in ConfigMap and Secrets and then restart pods for Deployment

-- Jose Armesto
Source: StackOverflow