environment.rb

ENV['RACK_ENV'] ||= 'development'

require 'rubygems'
require 'bundler'
Bundler.require(:default, ENV['RACK_ENV'].to_sym)

Rakefile

task :environment do
  require './environment'
  require './arrival'
end

namespace :db do
  desc 'Load the seed data from db/seeds.rb'
  task :seed => :environment do
    seed_file = File.join(File.dirname(__FILE__), 'db', 'seeds.rb')
    load(seed_file) if File.exist?(seed_file)
  end
end