"Ideally CLI flags merged over top of environment variables merged over top of configuration files."
I used to wish for that too but I have changed my mind. I think in real world applications with many options it is preferable to not allow every option to be set in every way.
Environment variables shine for properties that vary per instances which share config files and for system properties (think $GOMAXPROCS).
Secrets should never go in the
command line nor the environment.
There is no one size fits all. Arguments, environment and config files have different pros and cons and should be used accordingly.
I used to wish for that too but I have changed my mind. I think in real world applications with many options it is preferable to not allow every option to be set in every way.
Environment variables shine for properties that vary per instances which share config files and for system properties (think $GOMAXPROCS).
Secrets should never go in the command line nor the environment.
There is no one size fits all. Arguments, environment and config files have different pros and cons and should be used accordingly.