Recreate versions using Carrierwave with Ruby

Question

The website I am working on is going through a redesign and as such, our user images need to be re-sized. The website is currently using carrierwave gem to handle all image and video processing, and each image has a original file with a unique file name based on the following:

def filename
  if original_filename
    if model && model.read_attribute(:user_image).present?
      model.read_attribute(:user_image)
    else
      @name ||= "#{secure_token}.#{file.extension}" if original_filename.present?
    end
  end
end

and secure_token be generated by

def secure_token
  var = :"@#{mounted_as}_secure_token"
  model.instance_variable_get(var) or model.instance_variable_set(var, SecureRandom.uuid)
end

The task that is created to do this is:

##
# CarrierWave Amazon S3 File Reprocessor Rake Task
#
# Written (specifically) for:
# - CarrierWave
# - Ruby on Rails 3
# - Amazon S3
#
# Works with:
# - Any server of which you have write-permissions in the Rails.root/tmp directory
# - Works with Heroku
#
# Not tested with, but might work with:
# - Ruby on Rails 2 
#
# Might work with, after a couple of tweaks:
# - File System Storage
# - Cloud Files Storage
# - GridFS
#
# Examples:
#
# Reprocess all versions of User#avatar
#  rake carrierwave:reprocess class=User mounted_uploader=avatar
#
# Reprocess the versions: thumb, small, medium for User#avatar
#  rake carrierwave:reprocess class=User mounted_uploader=avatar versions='thumb, small, medium'
#
# Reprocess for an underlying association, for things like Embedded MongoDB Documents
# which are models you cannot access directly, but rather through a regular Document
#
# Embeds One (picture) Association
#  rake carrierwave:reprocess class=User association=picture mounted_uploader=image versions='thumb, small, medium'
#
# Embeds Many (pictures) Association
#  rake carrierwave:reprocess class=User association=pictures mounted_uploader=image versions='thumb, small, medium'
#
# WARNING
# There is an issue with "Rake", that you cannot name your mounted_uploader "file".
# If you do this, then you will not be able to reprocess images through this rake task
#  class User
#    include Mongoid::Document
#    mount_uploader :file, PictureUploader
#  end
#
# This will NOT work with reprocessing through Rake because the mounted_uploader uses the "file" attribute.

namespace :carrierwave do

  ##
  # Only tested with Amazon S3 Storage
  # Needs some minor modifications if you want to use this for File System Store, Cloud Files and GridFS probably.
  # This should work without Ruby on Rails as well, just set a different TMP_PATH.
  desc "Reprocesses Carrier Wave file versions of a given model."
  task :reprocess => :environment do

    ##
    # Load in the OPEN URI library to be able
    # to pull down and store the original file in a temp directory
    require 'open-uri'

    ##
    # Default constants
    TMP_PATH          = "#{Rails.root}/tmp/carrierwave"

    ##
    # Set environment constants
    CLASS             = ENV['class'].capitalize
    ASSOCIATION       = ENV['association'] || nil
    MOUNTED_UPLOADER  = ENV['mounted_uploader'].to_sym
    VERSIONS          = ENV['versions'].nil? ? Array.new : ENV['versions'].split(',').map {|version| version.strip.to_sym}

    ##
    # Find the Model
    MODEL = Kernel.const_get(CLASS)

    ##
    # Create the temp directory
    %x(mkdir -p "#{TMP_PATH}")

    ##
    # Find all records for the provided Model
    records = MODEL.all

    ##
    # Output to console
    puts "\nCarrier Wave Version Reprocessing!"
    puts "======================================="
    puts "Model:              #{CLASS}"
    puts "Mounted Uploader:   #{MOUNTED_UPLOADER}"
    puts "Association:        #{ASSOCIATION}" if ASSOCIATION
    puts "Versions:           #{VERSIONS.empty? ? "all" : VERSIONS.join(', ')}\n\n"

    ##
    # Run through all records
    records.each do |record|

      ##
      # Set the mounted uploader object
      # If it has a one-to-one association (singular) then that object
      # will be returned and wrapped in an array so we can "iterate" through it below.
      # 
      # If it has a one-to-many association then it will return the array of associated objects
      #
      # If no association is specified, it assumes the amounted uploader is attached to the specified CLASS 
      if ASSOCIATION
        if ASSOCIATION.singular?
          objects = [record.send(ASSOCIATION)]
        else
          objects = record.send(ASSOCIATION)        
        end
      else
        objects = [record]
      end

      ##
      # Iterates through the objects
      objects.each do |object|

        ##
        # Returns the mounted uploader object
        mounted_object = object.send(MOUNTED_UPLOADER)

        ##
        # Retrieve Filename
        filename = mounted_object.path.split('/').last

        ##
        # Output to console
        puts "Reprocessing: #{filename}"

        ##
        # Read out the original file from the remote location
        # and write it out to the temp directory (TMP_PATH)
        # This file will be used as the base file to reprocess
        # the versions. Once all versions have been processed,
        # this temp file will be directly removed.
        open(mounted_object.url) do |original_object|
          File.open(File.join(TMP_PATH, filename), 'w') do |temp_file|
            temp_file.write(original_object.read)
          end
        end

        ##
        # By default it will add all available versions to the versions variable
        # which means that all available versions will be reprocessed.
        # If the "versions" argument has been provided, then only the specified
        # version(s) will be set to the versions variable, and thus, only these
        # will be reprocessed.
        versions = mounted_object.versions.map {|version| version[0]}
        versions = VERSIONS unless VERSIONS.empty?

        ##
        # Reprocesses the versions
        versions.each do |version|
          mounted_object.send(version).cache!(File.open(File.join(TMP_PATH, filename)))
          mounted_object.send(version).store!
        end

        ##
        # Removes the temp file
        %x(rm "#{TMP_PATH}/#{filename}")
      end
    end
  end
end

The problem is that while it creates the new images, the files are saved under a new file name rather than following the naming laid out in the image uploader, so the website cannot find them. The following is an example of how the images are stored.

How it should be:

Original file: fdk392ks93_39ei.png

thumbnail version: thumb_fdk392ks93_39ei.png

How it is:

Original file: fdk392ks93_39ei.png

thumbnail version: thumb_fajeilkadifej_jakdjfi.png

Any help would be very appreciated.

Other info:

Model: User

Uploader: user_image (this is also the column name which stores the folder/file name)

Answer 1

After calling recreate_versions! you have to call save! on the model. You can check out this question where someone asked basically the same thing.

Answer 2

The README clearly states how to recreate Carrierwave versions:

https://github.com/jnicklas/carrierwave/blob/master/README.md

"You might come to a situation where you want to retroactively change a version or add a new one. You can use the recreate_versions! method to recreate the versions from the base file. This uses a naive approach which will re-upload and process the specified version or all versions, if none is passed as an argument.

instance = MyUploader.new
instance.recreate_versions!(:thumb, :large)

Or on a mounted uploader:

User.all.each do |user|
  user.avatar.recreate_versions!
end