upload_and_delete_file.rb

SIZES = [%w[small S], %w[medium M], %w[large L], %w[extra_large EL]]
SIZES.each do |size|
  upload_and_delete_local_file(key, image, size.first, size.last)
end

def upload_and_delete_local_file(key, image, size, file_size)
  obj = S3.bucket('unikaihatsu-s3').object(key.gsub 'original', size)
  obj.upload_file(Rails.public_path.join("#{file_size}_#{image.img_file_name}"), acl:'public-read')
  File.delete(Rails.public_path.join("#{file_size}_#{image.img_file_name}"))
end