Paperclip: Choose between saving files local or S3 at runtime - ruby-on-rails

Question

I'm using Paperclip for saving files. I have configured successfully for Paperclip saving files directly to Amazon S3. But in some situations, I need files only be saved locally. My question is: How can I do this.
Here is my example Paperclip configuration:
Paperclip.interpolates(:upload_url) { |attachment, style| "#{ENV.fetch('UPLOAD_PROTOCOL', 'http')}://#{ENV.fetch('UPLOAD_DOMAIN', 'localhost:3000')}/uploads/:class/:attachment/:id_:style.:extension" }
Paperclip::Attachment.default_options.merge!(
storage: :s3,
s3_region: ENV['CEPH_REGION'],
s3_protocol: 'http',
s3_host_name: ENV['CEPH_HOST_NAME'],
s3_credentials: {
access_key_id: ENV['CEPH_ACCESS_KEY_ID'],
secret_access_key: ENV['CEPH_SECRET_KEY'],
},
s3_options: {
endpoint: ENV['CEPH_END_POINT'],
force_path_style: true
},
s3_permissions: 'public-read',
bucket: ENV['CEPH_BUCKET'],
url: ':s3_path_url',
path: ':class/:id/:basename.:extension',
use_timestamp: false
)
module Paperclip
def self.string_to_io(options)
data = StringIO.new(options[:data])
data.class.class_eval{ attr_accessor :original_filename }
data.original_filename = options[:original_file_name]
data
end
end

Answer 1

You could use a lambda. As shown here. https://github.com/thoughtbot/paperclip#dynamic-configuration
it would look something like this.
class YOURMODEL < ActiveRecord::Base
has_attached_file :FILE, storage: lambda { |attachment| (attachment.instance.use_s3? ? :s3 : :filesystem) }
end
Then you would have to add a method use_s3? to your model to check if you wanted to store the file locally or with s3.