Env vars handling proposal

[acelaya]

Right now there are three levels of config.

• Hardcoded one
• Env vars (overrides previous one)
• Installer options (overrides previous two)

Ideally, it should work this way.

• Hardcoded one
• Installer options (overrides previous one)
• Env vars (overrides previous two)

But it's not possible the way it is implemented now, because the logic to read env vars is defined in config files, next to the base config they override (which is quite convenient).

And then, the installer options sit on another file, which overrides everything.

The options to change the behavior are.

• Move the logic to read env vars to another config file which always overrides installer options. not really an option, as it would always override the installer config no matter what.
• Move the logic to read env vars to a config post processor which overrides config dynamically, only if the appropriate env var had been defined.
• Make the installer generate a config file which also includes the logic to load env vars on it.
• Make the installer no longer generate the config structure, and instead generate a map with env vars and their values. Then Shlink would define those env vars if not defined already.