I have created a piece of software that I have chosen to license under the GPL. Its configuration is technically also code. Are any run-time configuration files also licensed under GPL? Do I have to disclose them if someone asks for them?The configuration is in a separate repository from the main code, but is imported (linked, I suppose) in the code. There is confidential information in the config files.
Licensing of configuration files that are technically code
licensing
First of all, if you have created the software yourself you are not bound by the GPL in any way even if you have chosen to distribute it under the GPL. You own the software, you don't need a license to use it, and you can do anything you want with it. You do not need to disclose anything. The rest of my answer is only relevant for users bound by the GPL.Regarding the configuration files, if they are required to build the software, they are decidedly a part of the corresponding source mentioned in Section 1 of the GPLv3:The Corresponding Source for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activitiesOr complete source in Section 3 in the GPLv2:For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable.As long as your software can be built and used without the configuration data itself, the configuration data doesn't belong to the complete/corresponding source. The configuration template files probably do though, but that's no issue I assume.