Download a Carrierwave Upload from S3

Download a Carrierwave upload from S3

Thanks apneadiving. It was as easy as:

image = MiniMagick::Image::open(card.image.to_s)
image.write(somepath)

Carrierwave & Amazon S3 file downloading/uploading

Looks like you want to upload to S3, but have not-public URLs. Instead of downloading the file from S3 and using send_file, you can redirect the user to the S3 authenticated URL. This URL will expire and only be valid for a little while (for the user to download).

Check out this thread: http://groups.google.com/group/carrierwave/browse_thread/thread/2f727c77864ac923

Since you're already setting fog_public to false, do you get an authenticated (i.e. signed) url when calling resource.upload_url

Downloading an image from S3 using carrierwave (without open)

I can suggest you use JavaScript to download a data(file/image) anything.

You can do ajax call to server to get an url.

#removed: target: '_self' no need it anymore
#added: remote: true
<%= link_to download_media_partnership_path(@partner, m: m.id), remote: true, data: {disable_with: "<i class='fa fa-spinner fa-spin media-icon'></i>"} 
    <i class="fa fa-download media-icon download" id=""></i>
<% end %>

def download_media
  @media = TeamMedia.find(params[:m])
  @url = @media.attachment.url

  respond_to do |format|
    format.js {}
  end
end

Check this Link and implement into your javascript assets.

Do not forget to create download_media.js.erb file.

#download_media.js.erb

downloadFile("<%= @url %>");

Downloading and zipping files that were uploaded to S3 with CarrierWave

I've managed to solve the problem with help from @ffoeg

The solution offered by @ffoeg didn't work quite so well for me since I was dealing with zip files > 500 MB which caused me problems on Heroku. I've therefor moved the zipping to a background process using resque:

app/workers/photo_zipper.rb:

require 'zip/zip'
require 'zip/zipfilesystem'
require 'open-uri'
class PhotoZipper
  @queue = :photozip_queue

  #I pass 
  def self.perform(id_of_object_with_images, id_of_user_to_be_notified)
    user_mail = User.where(:id => id_of_user_to_be_notified).pluck(:email)
    export = PhotoZipper.generate_zip(id_of_object_with_images, id_of_user_to_be_notified)

    Notifications.zip_ready(export.archive_url, user_mail).deliver
  end

    # Zipfile generator
  def self.generate_zip(id_of_object_with_images, id_of_user_to_be_notified)
    object = ObjectWithImages.find(id_of_object_with_images)
    photos = object.images
    # base temp dir
    temp_dir = Dir.mktmpdir
    # path for zip we are about to create, I find that ruby zip needs to write to a real file
    # This assumes the ObjectWithImages object has an attribute title which is a string.
    zip_path = File.join(temp_dir, "#{object.title}_#{Date.today.to_s}.zip")

    Zip::ZipOutputStream.open(zip_path) do |zos|
      photos.each do |photo|
        path = photo.photo.path
        zos.put_next_entry(path)
        zos.write photo.photo.file.read
      end
    end

    #Find the user that made the request
    user = User.find(id_of_user_to_be_notified)

    #Create an export object associated to the user
    export = user.exports.build

    #Associate the created zip to the export
    export.archive = File.open(zip_path)

    #Upload the archive
    export.save!

    #return the export object
    export
  ensure

    # clean up the tempdir now!
    FileUtils.rm_rf temp_dir if temp_dir
  end

end

app/controllers/photos_controller.rb:

  format.zip do
    #pick the last ObjectWithImages.. ofcourse you should include your own logic here
    id_of_object_with_images = ObjectWithImages.last.id

    #enqueue the Photozipper task
    Resque.enqueue(PhotoZipper, id_of_object_with_images, current_user.id)

    #don't keep the user waiting and flash a message with information about what's happening behind the scenes
    redirect_to some_path, :notice => "Your zip is being created, you will receive an e-mail once this process is complete"
  end

Many thanks to @ffoeg for helping me out. If your zips are smaller you could try @ffoeg's solution.

How do I dynamically generate a download link for file uploaded to S3 with Carrierwave?

CarrierWave allows you to set the fog_public and fog_authenticated_url_expiration options both for every uploader (through an initializer) or on a specific uploader. In the latter case you just place self.fog_public = false and self.fog_authenticated_url_expiration = 123 inside your uploader class definition. With these two options set, any calls to model.uploader.url will return a specially built URL that will expire after the set amount of time.

How do I open a CSV file that I uploaded with Carrierwave and Fog to Amazon S3?

I tried Jared Beck's idea and it's working now, basically I added this condition to my BG job:

if Rails.env.production? || Rails.env.staging?
  url = cbf.billing_file_name.url
  cbf.billing_file_name.download!(url)
end

So the final code looks like this:

def self.perform(client_billing_file_id, email)
  cbf = ClientBillingFile.find(client_billing_file_id)
  if Rails.env.production? || Rails.env.staging?
    url = cbf.billing_file_name.url
    cbf.billing_file_name.download!(url)
  end
  filepath = cbf.billing_file_name.current_path
  csv_file = CSV.read(filepath, headers: true)
  .
  .
  .
end

how to direct upload to s3 using carrierwave rails

You can use "fog-aws" gem if you want to upload to S3 using carrierwave.

Here's a link. Scroll down to Using Amazon S3 section for details.

Also, you can take a look at this question. It explains how to use fog to generate pre-signed URLs for direct uploads.

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