Why is robots.txt not available in production?

Question

Ruby on Rails

When run in development, the file is available at site.ru/robots.txt.
As soon as I run it in production, I get a 404 error. What's the problem?

Answer 1

because in development mode the rails server also gives the statics from the public folder, because it's practical
Ruby is too slow to do it in production, your main web server - nginx or at least apache should do it in
config/environments/production. rb
rails < 4 - config.serve_static_assets = true
rails = 5 - config.serve_static_files = true