realtime updating configmaps?

I'm working on moving a vpn server to eks using terraform and I need a solution for keeping the list of client vpn keys updated. The keys are locates in a s3 bucket, and the current solution is to have a cronjob on the containers, using aws cli with the API credentials injected as environmental variables to pull the keys and extract them to the keys folder. I was wondering if there is a native solution in kubernetes/terraform to have the keys pulled, extracted and placed in the folder using configmaps, and have it update each time and new compressed key file is pushed in s3? that way I won't have to inject the API creds into each pod and risk it.