Reload service account keyfile periodically

Hi,

We run the CloudSQL proxy in our kubernetes cluster as a deployment and sometimes we rotate the secret that is used to provide the credentials file for IAM authentication.

As a result the credentials loaded at start-up of the proxy become invalid and the proxy begins printing invalid credentials errors, but does not error out. What's the recommended way to handle this situation? Is there a way to have the proxy reload the credentials?

My understanding is that mounted secrets are updated automatically, so it's up to the application [to respond accordingly](https://stackoverflow.com/questions/37945800/update-kubernetes-secrets-doesnt-update-running-container-env-vars):

```
Mounted Secrets are updated automatically When a secret being already consumed in a volume is updated, projected keys are eventually updated as well. The update time depends on the kubelet syncing period.
```