Rake task to configure Spree Authorize.net gateway

yoursite.rake

# rake yoursite:setup_gateway

namespace :yoursite
  desc "Set up gateway"
  task :setup_gateway => :environment do
    Gateway.transaction do
      auth_net = "Authorize.net"

      gateway = Gateway.find_by_name_and_environment(auth_net, RAILS_ENV)      
      gateway.destroy unless gateway.nil?

      gateway = Gateway::AuthorizeNet.create(
                      :name        => auth_net, 
                      :environment => RAILS_ENV,
                      :description => auth_net,
                      :test_mode   => "false",
                      :active      => "true",
                      :server      => (RAILS_ENV == "production") ? "live" : "test"
                      )

      if RAILS_ENV == "production"
        gateway.set_preference(:login,    "-- your production key --")
        gateway.set_preference(:password, "-- your production password --")
      else
        gateway.set_preference(:login,    "-- your test key --")
        gateway.set_preference(:password, "-- your test password --")
      end
      
      gateway.save!
    end
  end
end