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I have defined an environment variable for a container from a Configmap, But I want to apply changes automatically when changing the variable value in the ConfigMap. Maybe we can target an environment variable in volume path !?

Smaillns
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  • I know this thread is old, but you may wish to look into OpenFeature. In particular the https://github.com/open-feature/open-feature-operator which makes the process you describe much easier and more powerful. – A. Gardner May 05 '23 at 04:21

2 Answers2

1

In the following lines I'll try to exhibit an idea (It can be considered as solution, at least for the moment), it consist of mounting the configmap values as Volume, 

spec:
  containers:
  - name
    ...
    volumeMounts:
      - name: config-volume
        mountPath: /etc/config   #just an example
  volumes:
    - name: config-volume
      configMap:
        name : <name-of-configmap>
        items:
          - key: <key-in-onfigmap>
            path: keys

As result we will get the value of our configMap Key inside a volume file (/etc/config/keys) we can ensure by executing theses commands 

kubectl exec -it <name-of-pod> sh      #to get a shell to the running container/pod
cat /etc/config/keys                   #

Note : there a delay time from the moment when the ConfigMap is updated to the moment when keys are projected to the pod (it can be as long as kubelet ConfigMap sync period + ttl of ConfigMap cache in kubelet )

Take a look to this to make it more clear, Best regards

Smaillns
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0

Propagation of config map changes has been discussed for a long time and still not implemented: https://github.com/kubernetes/kubernetes/issues/22368

I suggest using helm upgrade process (or similar) to just rollout the same version of an app with the new settings. In this way you have additional controls: you can do a rolling update, you can rollback, you can do canary and so on.

Max Lobur
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