I recently tried VERY hard to override the database configuration bassed on
ENV vars or actual API calls. This task is almost next to impossible.
I know that the database.yml file is parsed as ERB but that is sane for
simple ENV replacement if you want to actually change which database adaptor
it is (requires extra config/params) it becomes messy.
I found https://github.com/rails/rails/issues/5297 which explains the
issue/solution far better then I could.
Active record supports this natively, I can't see why rails would force the
requirement of a database.yml and for it to have a "production" section. see
As I mentioned on the ticket, I would rather have ENV["DATABASE_URL"]
supported as well, but I can't see how it's "VERY hard to override".
I've been using variations of that for a long time, and it works pretty well.