Ignore un-existence of database.yml - #460

@maxmeyer thank you for the contribution. The code seems to be breaking a rule in rubocop, could you take care of it before I merge?

@gabrielpoca Yes, of course. Done.

@gabrielpoca Ok?

Thank you @maxmeyer! I only now got the time to look at this change more carefully, if the config/database.yml already uses <%= ENV["DATABASE_URL"] %> in production, what is the scenario in which you need this change?

The problem is this: I removed the file in my container, as active_record can be used with DATABASE_URL defined, but starting stringer fails because File.load fails because the file does not exist.

@maxmeyer I hope you don't mind me insisting, but it's not clear for me yet. If config/database.yml is already using DATABASE_URL, why are you removing the file?

@gabrielpoca Because I was unaware of this and overhead it in your comment.

Thinking more about it, the approach of having this indirection with config/database.yml seems to be less flexible as I'm not able to run a container in development environment configured via DATABASE_URL, correct?

@maxmeyer yes, you are right, it's less flexible. It does work in production, but in development you would have to replace the file. If no one has complained about it not working when running in development, do you still think we should merge this?

@gabrielpoca I think yes, normally I try to build my docker images that they work in all environments the same. This https://12factor.net/config may give some more info why it makes sense to configure an application via environment variables.

@pascalw You added the docker support. What do you think? Shall the image work in all environments -
prod, staging, ... the same?

@maxmeyer @gabrielpoca I do think ideally the Docker image works in every environment.

However I'm not convinced the changes in this PR are required to achieve that. For example I'm able to run Stringer with RACK_ENV=development and specifying a DB url like this:

docker run --rm -it -e DATABASE_URL="sqlite3:':memory:'" -e RACK_ENV=development -p 8080:8080 mdswanson/stringer

Afaik Activerecord prioritizes DATABASE_URL over config.yml.

@mockdeep I think this one can be closed

Sure, sounds good. @maxmeyer if you have any other thoughts on this, happy to hear them.

This is fine for me. I'm not using Stringer anymore.