How do you usually configure an app? Over the decades our industry came up with multiple approaches, like providing command line arguments, various config files, registry settings and environment variables. Even hardcoding certain options into the app itself also works sometimes. Whenever we need to reconfigure the app we’d just go to its host, change a setting or two, and the job is done.
And now imagine a challenge: you have a cluster of services that come and go, they have different versions and locations, and you need to reconfigure all of them. How would you do that?