[RFC] Add option to strip the env var prefix from config in settings files

[taranlu-houzz]

Is your feature request related to a problem? Please describe. I prefer to have the env var names exactly match the names used in the config file and application code.

Describe the solution you'd like

• Add a param to the dynaconf config that is off by default (e.g. something like settings_files_strip_prefix)
• When parsing the settings files, if the config name begins with the prefix set via envvar_prefix, strip that (dealing with the following underscore would probably require additional logic or at least clear documentation).
• If the config name doesn't begin with the prefix, just proceed as usual.
• Ultimately, I would like the following ways of setting a config value to be properly merged to the same final attribute on the dynaconf object:
  • env var with prefix: PREFIX_MY_VAR=123
  • config name with prefix: in setting.toml: PREFIX_MY_VAR = "123"
  • config name without prefix: in settings.toml: MY_VAR = "123"
  • So that the final config value is accesses as dynaconf_obj.MY_VAR

Describe alternatives you've considered This isn't an essential feature, just a nice to have.

Additional context Add any other context or screenshots about the feature request here.

[rochacbruno]

if you set envvar_prefix=False Dynaconf will load all the envvars regardless of prefix, is that what you are looking for?

[taranlu-houzz]

@rochacbruno Not quite. Right now, if I enable envvar_prefix, it will detect PREFIX_MY_VAR=123 in the environment and store it as MY_VAR, but if I set PREFIX_MY_VAR = "123" in the settings file, it will pick that up with that name including the prefix, so I will have dynaconf_obj.MY_VAR and dynacof_obj.PREFIX_MY_VAR.

Basically, I would like to have the flexibility to specify:

• PREFIX_MY_VAR in the environment
• PREFIX_MY_VAR in the config file
• MY_VAR in the config file And have them all refer to the same config setting.

[rochacbruno]

Ok, got it now.

We have prefix filtering, but that will just apply the same filtering done to envvars to any source file.

It looks like the feature you are looking for is the ability to set alias #1137

Lets keep this issue open to be considered when implementing the new alias system.