I've recently released a comprehensive tool for managing config / env vars - https://dmno.dev. It is the only tool I've seen that natively understands monorepos. This means you can reuse config from the root or other services (See https://dmno.dev/docs/guides/schema/#sharing-config-between-...)

It is admittedly geared towards JS/TS stacks, but supports other languages by running commands via `dmno run -- yourcommand` which will inject the resolved config into your command as env vars. Generating types and adding helpers for other languages should not be too tough. We'll follow user demand as to which to implement first.

We are currently working on a tool that will help you run and manage your local dev services as well, but it is not ready yet. In the meantime, you can check out https://tilt.dev which is oriented around docker and k8s but does have some ability to just run arbitrary scripts. As for running scripts in general, I've had some success hacking together pnpm and turborepo, even to run scripts in non js/ts services. Lastly, I'll mention https://moonrepo.dev/ as it has more native support for polyglot repos, and its notion of task inheritance keep things fairly clean, especially in a larger repo with many services.