rails-init-process.md

root.rb

application.rb

Here is note in that file

# Settings in config/environments/* take precedence over those specified here.
# Application configuration should go into files in config/initializers
# -- all .rb files in that directory are automatically loaded.

# Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
# Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
# config.time_zone = 'Central Time (US & Canada)'

# The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
# config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
# config.i18n.default_locale = :de

What you can configure here are:

asset   # Sprockets::Environment
config  # Rails::Application::Configuration

See Rails::Application::Configuration

You can set asset here

Booting WEBrick

=> Booting WEBrick
=> Rails 4.0.5 application starting in development on http://0.0.0.0:3300
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server

environment.rb

# Initialize the Rails application.
Slcc::Application.initialize!

environment/development.rb

initializers/*

routes.rb

Dislaying logs

[2014-06-10 17:01:47] INFO  WEBrick 1.3.1
[2014-06-10 17:01:47] INFO  ruby 2.0.0 (2013-05-14) [x86_64-darwin12.2.1]
[2014-06-10 17:01:47] INFO  WEBrick::HTTPServer#start: pid=50678 port=3300

Refs

• Official Guides