paperclip_migration.rake

# migrate all images to S3

namespace :paperclip_migration do  
  desc "migrate files from filesystem to s3"
  task :migrate_to_s3 => :environment do
    local_filesystem_root = Rails.root.to_s + "/public/system"
    # Fetch all models and find out which ones have paperclip attachments
    Rails.application.eager_load!
    models = ActiveRecord::Base.send(:descendants).select {|model| model.respond_to?(:attachment_definitions) }

    models.each do |model|
      definitions = model.attachment_definitions
      attachment_types = model.attachment_definitions.keys

      model.find_each do |record|
        attachment_types.each do |attachment_type|
          attachment = Paperclip::Attachment.new(attachment_type, record, definitions[attachment_type].except(:s3_credentials, :storage))

          next if attachment.path.nil? # skip if this record has no image

          if File.exists?(local_filesystem_root + attachment.path)
            file_data = File.open(local_filesystem_root + attachment.path)
            puts "Storing file: #{local_filesystem_root + attachment.path} on Amazon S3..."
            record.send("#{attachment_type}=", file_data)
            record.send("#{attachment_type}").save
          else
            puts "Could not find: #{local_filesystem_root + attachment.path}. Skipping..."
          end
        end
      end
    end
  end
end