I have an AppEngine Classic application written in Go, and as part of this, I have a number of keys which I would like to not have in the code repo.
I would like to have default keys in the repo for testing purposes, but keep the production keys secret. I know I can specify which files not to upload to the repo with my .gitignore file. However, I'm not sure what the best way to do this is so that other developers can build and tests the code without access to the file file.
What is the most practical way to keep keys out of the repo, while still having the code compile and test when the file with the keys is not present?