[CentralOH] how to keep track of multiple configurations

[jep200404 at columbus.rr.com]

On Wed, 23 Sep 2015 15:57:33 -0400, jep200404 at columbus.rr.com wrote:

> how to keep track of multiple (non-secret) configurations:
>     multiple configurations in one file
>     that file _is_ in repo
>     config file has dictionary
>         keys are configuration names
>     when installing/applying a configuration
>         specify which configuration to use by command line argument

How does one apply this to Ansible inventory and group_vars/all files?
Does one create the inventory and group_vars/all files from 
the dictionary configuration files described above?-