db:dump_seed_fu[model]で実行。 db:seed_fuで使えるseedデータがdb/fixtures内に生成されるrake task。

db.rake

# ./lib/tasks/db.rake

require 'active_record'
@logger = Logger.new(STDOUT)

namespace :db do
  desc "Make seed data importable with seed_fu"
  task :dump_seed_fu, [:model] => :environment do |t, args|
    model_name = args.model.underscore
    class_name = args.model.camelize
    seed = SeedFu::Writer.write("db/fixtures/#{model_name.pluralize}.rb", class_name: "#{class_name}") do |writer|
      Object.const_get("#{class_name}").order(:id).find_each do |m|
        writer << m.attributes
      end
    end
    @logger.info "create db/fixtures/#{model_name.pluralize}.rb"
  end
end