We do both, to a point. We use Hashicorp's Consul to push config changes to running systems, but we sync it from a repo using an internal git2consul type thing.

We do both, to a point. We use Hashicorp's Consul to push config changes to running systems, but we sync it from a repo using an internal git2consul type thing. It's nice to be able to push things into the system while it's running without hopping through all the hoops of qa, staging, etc. We then usually move it into the applications base configs in the app repo if it's going to stick around for more than a day or two to keep things tidy. There's nothing wrong with a service to push config into a system at run-time, and you don't have to throwaway the benefits of the git history.