Rake Tasks for Carrier Wave for reprocessing versions.

carrierwave.rake

namespace :carrierwave do

  desc 'Reprocesses Carrier Wave file versions of a given model.'
  task reprocess_all: :environment do

    ActiveRecord::Base.descendants.each do |m|
      next if m.uploaders.empty?

      puts "Reprocess #{m.name}"
      m.all.each do |entry|
        m.uploaders.each do |uploader_name, uploader|

          image = entry.method(uploader_name).call
          next if image.path.blank?

          puts "  > \##{entry.id} #{uploader_name}"
          image.recreate_versions!
        end
      end
    end
  end
end