Lifecycle init to render. Where can I place an INI file?

I'd like to add an ini based configuration to my setup, that is accessible to the files in the config folder, but at a level within the app that doesn't require me to go into each file and manually add the command to parse the ini over and over since thats redundant overhead I dont want.

The main purpose to this file is so I can store various settings such as db credentials for different environments, ie development, stage, beta, production... as well as other various configurations but keep them locked down in such as way only those who need to know them will know them as such would be the case with the production environment.

So the overall question is where can I place an INI file into the mix as its loading that will be accessible to all that gets loaded including the stuff in the conf folder. I am looking for something above controller, and the hooks to them.