How to change default port of a Rails 4 app?

Question

I know that I can start a rails server on another port via -p option. But I\'d like to setup another port per application as long as I start webrick.

An

Answer 1

Append this to config/boot.rb:

require 'rails/commands/server'

module DefaultOptions
  def default_options
    super.merge!(Port: 3001)
  end
end

Rails::Server.send(:prepend, DefaultOptions)

Note: ruby >= 2.0 required.