Paperclip S3 copy attachments

s3_copy_attachments.rb

### S3 implementation of Paperclip module that supports deep
### cloning of objects by copying image attachments.
###
### Tested with: aws-sdk (1.33.0)
###
### Refer to Paperclip issue: https://github.com/thoughtbot/paperclip/issues/1361#issuecomment-39684643
### Original gist works with fog: https://gist.github.com/stereoscott/10011887
### gist works from which this code is derived: https://gist.github.com/ksin/7747334d60b1947f14e9

module Paperclip

  module CopyAttachments

    def copy_attachments_from(source_obj, source_bucket = nil, destination_bucket = nil)
      self.class.attachment_definitions.keys.each do |attachment_name|
        source_attachment      = source_obj.send(attachment_name)
        next if source_attachment.blank?

        destination_attachment = self.send(attachment_name)

        source_bucket      ||= bucket source_attachment
        destination_bucket ||= bucket destination_attachment

        [:original, *destination_attachment.styles.keys].uniq.map do |style|
          source_path      = path(source_attachment, style)
          destination_path = path(destination_attachment, style)

          Paperclip.log("Copying #{style} from #{source_bucket}/#{source_path} ---> #{destination_bucket}/#{destination_path}")

          begin
            copy_object(source_bucket, source_path, destination_bucket, destination_path)
          rescue AWS::S3::Errors::NotFound
            Paperclip.log("Could not find #{style} from #{source_bucket}/#{source_path}")
          end

        end
      end
    end

    private

    def path(attachment, style)
      path = attachment.path(style)
      path.slice!(0) if path.start_with? '/'
      path
    end

    def bucket(attachment)
      s3.buckets[attachment.bucket_name]
    end

    def s3
      return @s3 if @s3

      # Load credentials from a file.
      # Change this line (and key names below) to match your environment.
      creds = YAML.load(File.read("#{ Rails.root }/config/s3.yml"))

      @s3 = AWS::S3.new(
        access_key_id: creds['access_key_id'],
        secret_access_key: creds['secret_access_key'],
        s3_endpoint: 'YOUR_S3_ENDPOINT'
      )
    end

    def copy_object(source_bucket, source_path, destination_bucket, destination_path)
      source_obj = source_bucket.objects[source_path]
      destination_obj = destination_bucket.objects[destination_path]
      source_obj.copy_to(destination_obj, acl: :public_read)
    end

  end

end

@builtinnya What version of Paperclip does this work with?

@airblade It works at least with paperclip 4.2.4