Ask HN: Simple Terraform like tool for customer configs?

I work for a company that has a few large accounts say 20 and each of these have settings that are kept in a db.

These settings are only updated a few times a year or when we add a new account. We currently use a script to update the settings but feels like this is the wrong approach. I'd much prefer a declarative model. We use terraform to manage our infrastructure and something like that would be ideal but it looks like writing a custom provider is a fair amount of work, or at least more than I was hoping for.

Anyone have any suggestions on a better approach?