ruby-on-rails – 将回形针S3图像迁移到新的URL /路径格式

namespace :paperclip_migration do

  desc 'Migrate data'
  task :migrate_s3 => :environment do
    # Make sure that all of the models have been loaded so any attachments are registered
    puts 'Loading models...'
    Dir[Rails.root.join('app','models','**/*')].each { |file| File.basename(file,'.rb').camelize.constantize }

    # Iterate through all of the registered attachments
    puts 'Migrating attachments...'
    attachment_registry.each_definition do |klass,name,options|
      puts "Migrating #{klass}: #{name}"
      klass.find_each(batch_size: 100) do |instance|
        attachment = instance.send(name)

        unless attachment.blank?
          attachment.styles.each do |style_name,style|
            old_path = interpolator.interpolate(old_path_option,attachment,style_name)
            new_path = interpolator.interpolate(new_path_option,style_name)
            # puts "#{style_name}:ntold: #{old_path}ntnew: #{new_path}"
            s3_copy(s3_bucket,old_path,new_path)
          end
        end
      end
    end

    puts 'Completed migration.'
  end

  #############################################################################
  private

  # Paperclip Configuration
  def attachment_registry
    Paperclip::AttachmentRegistry
  end

  def s3_bucket
    ENV['S3_BUCKET']
  end

  def old_path_option
    ':class/:id_partition/:attachment/:hash.:extension'
  end

  def new_path_option
    ':class/:attachment/:id_partition/:style/:filename'
  end

  def interpolator
    Paperclip::Interpolations
  end

  # S3
  def s3
    AWS::S3.new(access_key_id: ENV['S3_KEY'],secret_access_key: ENV['S3_SECRET'])
  end

  def s3_copy(bucket,source,destination)
    source_object = s3.buckets[bucket].objects[source]
    destination_object = source_object.copy_to(destination,{metadata: source_object.metadata.to_h})
    destination_object.acl = source_object.acl
    puts "Copied #{source}"
  rescue Exception => e
    puts "*Unable to copy #{source} - #{e.message}"
  end

end