CarrierWave is a great way to upload files from Ruby applications, but since processing and saving is done in-process, it doesn't scale well. A better way is to upload your files directly then handle the processing and saving in a background process.
CarrierWaveDirect works on top of CarrierWave and provides a simple way to achieve this.
Right now, CarrierWaveDirect works with Amazon S3. Adding support for Google Storage for Developers should be fairly straight forward since the direct upload form is essentially the same. Please see the contributing section if you would like support for Google Storage for Developers or any other service that provides direct upload capabilities.
Please be aware that this gem (and S3 in general) only support single file uploads. If you want to upload multiple files simultaneously you'll have to use a javascript or flash uploader.
More information, and how-tos available on the wiki
Install the latest release:
gem install carrierwave_direct
In Rails, add it to your Gemfile:
gem 'carrierwave_direct'
Note that CarrierWaveDirect is not compatible with Rails 2.
Please read the CarrierWave readme first
CarrierWaveDirect works with fog so make sure you have CarrierWave set up and initialized with your fog credentials, for example:
CarrierWave.configure do |config|
config.fog_credentials = {
:provider => 'AWS', # required
:aws_access_key_id => 'xxx', # required
:aws_secret_access_key => 'yyy', # required
:region => 'eu-west-1' # optional, defaults to 'us-east-1'
}
config.fog_directory = 'name_of_directory' # required
config.fog_host = 'https://assets.example.com' # optional, defaults to nil
config.fog_public = false # optional, defaults to true
config.fog_attributes = {'Cache-Control'=>'max-age=315576000'} # optional, defaults to {}
end
If you haven't already done so generate an uploader
rails generate uploader Avatar
this should give you a file in:
app/uploaders/avatar_uploader.rb
Check out this file for some hints on how you can customize your uploader. It should look something like this:
class AvatarUploader < CarrierWave::Uploader::Base
storage :file
end
Remove the line storage :file and replace it with include CarrierWaveDirect::Uploader so it should look something like:
class AvatarUploader < CarrierWave::Uploader::Base
include CarrierWaveDirect::Uploader
end
This adds the extra functionality for direct uploading.
If you're not using Rails you can generate a direct upload form to S3 similar to this (see also http://doc.s3.amazonaws.com/proposals/post.html#A_Sample_Form):
<form action="https://s3-bucket.s3.amazonaws.com/" method="post" enctype="multipart/form-data">
<input type="hidden" name="key" value="uploads/${filename}">
<input type="hidden" name="AWSAccessKeyId" value="YOUR_AWS_ACCESS_KEY">
<input type="hidden" name="acl" value="private">
<input type="hidden" name="success_action_redirect" value="http://localhost/">
<input type="hidden" name="policy" value="YOUR_POLICY_DOCUMENT_BASE64_ENCODED">
<input type="hidden" name="signature" value="YOUR_CALCULATED_SIGNATURE">
<input name="file" type="file">
<input type="submit" value="Upload to S3">
</form>
by making use of the following methods in your uploader:
uploader = AvatarUploader.new
uploader.direct_fog_url # return the url to post to based off your bucket name
uploader.key # returns a key based off your store_dir
uploader.aws_access_key_id # returns your aws_access_key_id from your fog configuration
uploader.acl # returns your acl from your fog configuration
uploader.success_action_redirect= # sets the success action redirect url
uploader.success_action_redirect # gets the success action redirect url
uploader.policy # a base 64 encoded policy document
uploader.signature # your signature
If you are using Rails and you've mounted your uploader like this:
class User < ActiveRecord::Base
mount_uploader :avatar, AvatarUploader
end
things just got a whole lot easier. You can generate a direct upload form like this:
class AvatarController < ApplicationController
def new
@uploader = User.new.avatar
@uploader.success_action_redirect = new_user_url
end
end
<%= direct_upload_form_for @uploader do |f| %>
<%= f.file_field :avatar %>
<%= f.submit %>
<% end %>
You can also pass html options like this:
<%= direct_upload_form_for @uploader, :html => { :target => "_blank_iframe" } do |f| %>
<%= f.file_field :avatar %>
<%= f.submit %>
<% end %>
Note if User is not an ActiveRecord object e.g.
class User
mount_uploader :avatar, AvatarUploader
end
you can still use the form helper by including the ActiveModel modules your uploader:
class AvatarUploader < CarrierWave::Uploader::Base
include CarrierWaveDirect::Uploader
include ActiveModel::Conversion
extend ActiveModel::Naming
end
Note if you're using Rails 3.0.x you'll also need to disable forgery protection
# config/application.rb
config.action_controller.allow_forgery_protection = false
Once you've uploaded your file directly to the cloud you'll probably need a way to reference it with an ORM and process it.
Processing and saving file uploads are typically long running tasks and should be done in a background process. CarrierWaveDirect gives you a few methods to help you do this with your favorite background processor such as DelayedJob or Resque.
If your upload was successful then you will be redirected to the success_action_redirect url you specified in your uploader. S3 replies with a redirect like this: http://example.com?bucket=your_fog_directory&key=uploads%2Fguid%2Ffile.ext&etag=%22d41d8cd98f00b204e9800998ecf8427%22
The key is the most important piece of information as we can use it for validating the file extension, downloading the file from S3, processing it and re-uploading it.
If you're using ActiveRecord, CarrierWaveDirect will by default validate the file extension based off your extension_white_list in your uploader. See the CarrierWave readme for more info. You can then use the helper filename_valid? to check if the filename is valid. e.g.
class UsersController < ApplicationController
def new
@user = User.new(params)
unless @user.filename_valid?
flash[:error] = @user.errors.full_messages.to_sentence
redirect_to new_avatar_path
end
end
end
CarrierWaveDirect automatically gives you an accessible key attribute in your mounted model when using ActiveRecord. You can use this to put a hidden field for the key into your model's form.
<%= form_for @user do |f| %>
<%= f.hidden_field :key %>
<%= f.label :email %>
<%= f.text_field :email %>
<%= f.submit %>
<% end %>
then in your controller you can do something like this:
def create
@user = User.new(params[:user])
if @user.save_and_process_avatar
flash[:notice] = "User being created"
redirect_to :action => :index
else
render :new
end
end
Now that the basic building blocks are in place you can process and save your avatar in the background. This example uses Resque but the same logic could be applied to DelayedJob or any other background processor.
class User < ActiveRecord::Base
def save_and_process_avatar(options = {})
if options[:now]
self.remote_avatar_url = avatar.direct_fog_url(:with_path => true)
save
else
Resque.enqueue(AvatarProcessor, attributes)
end
end
end
class AvatarProcessor
@queue = :avatar_processor_queue
def self.perform(attributes)
user = User.new(attributes)
user.save_and_process_avatar(:now => true)
end
end
The method self.remote_avatar_url= from CarrierWave downloads the avatar from S3 and processes it. save then re-uploads the processed avatar to to S3
Your users may find it convenient to upload a file from a location on the Internet via a URL. CarrierWaveDirect gives you another accessor to achieve this.
<%= form_for @user do |f| %>
<%= f.hidden_field :key %>
<% unless @hangover.has_avatar_upload? %>
<%= f.label :remote_avatar_net_url %>
<%= f.text_field :remote_avatar_net_url %>
<%= f.submit %>
<% end %>
class User < ActiveRecord::Base
def save_and_process_avatar(options = {})
if options[:now]
self.remote_avatar_url = has_remote_avatar_net_url? ? remote_avatar_net_url : avatar.direct_fog_url(:with_path => true)
save
else
Resque.enqueue(AvatarProcessor, attributes)
end
end
end
The methods has_avatar_upload?, remote_avatar_net_url and has_remote_avatar_net_url? are automatically added to your mounted model
Along with validating the extension of the filename, CarrierWaveDirect also gives you some other validations:
validates :avatar :is_uploaded => true
Validates that your mounted model has an avatar uploaded from file or specified by remote url. It does not check that an your mounted model actually has a valid avatar after the download has taken place. Turned off by default
validates :avatar, :is_attached => true
Validates that your mounted model has an avatar attached. This checks whether there is an actual avatar attached to the mounted model after downloading. Turned off by default
validates :avatar, :filename_uniqueness => true
Validates that the filename in the database is unique. Turned on by default
validates :avatar :filename_format => true
Validates that the uploaded filename is valid. As well as validating the extension against the extension_white_list it also validates that the upload_dir is correct. Turned on by default
validates :avatar :remote_net_url_format => true
Validates that the remote net url is valid. As well as validating the extension against the extension_white_list it also validates that url is valid and has only the schemes specified in the url_scheme_whitelist. Turned on by default
As well as the built in validations CarrierWaveDirect provides, some validations, such as max file size and upload expiration can be performed on the S3 side.
CarrierWave.configure do |config|
config.validate_is_attached = true # defaults to false
config.validate_is_uploaded = true # defaults to false
config.validate_unique_filename = false # defaults to true
config.validate_filename_format = false # defaults to true
config.validate_remote_net_url_format = false # defaults to true
config.max_file_size = 10.megabytes # defaults to 5.megabytes
config.upload_expiration = 1.hour # defaults to 10.hours
end
CarrierWaveDirect provides a couple of helpers to help with integration and unit testing. You don't want to contact the Internet during your tests as this is slow, expensive and unreliable. You should first put fog into mock mode by doing something like this.
Fog.mock!
def fog_directory
ENV['AWS_FOG_DIRECTORY']
end
connection = ::Fog::Storage.new(
:aws_access_key_id => ENV['AWS_ACCESS_KEY_ID'],
:aws_secret_access_key => ENV['AWS_SECRET_ACCESS_KEY'],
:provider => 'AWS'
)
connection.directories.create(:key => fog_directory)
If your using Capybara with Cucumber or RSpec, CarrierWaveDirect gives you a few useful helpers. To get the Capybara helpers, include the module into your test file or helper
describe AvatarUploadSpec
include CarrierWaveDirect::Test::CapybaraHelpers
end
To attach a file to the direct upload form you can use
attach_file_for_direct_upload('path/to/file.ext')
To simulate a successful upload and redirect to S3 you can use
upload_directly(AvatarUploader, "Upload to S3")
This will click the Upload to S3 button on the form and redirect you to the success_action_redirect url (in the form) with a sample response from S3
To simulate an unsuccessful upload you can pass :success => false and you'll remain on the upload page e.g.
upload_directly(AvatarUploader, "Upload to S3", :success => false)
You can also use find_key and find_upload_path to get the key and upload path from the form
If your mounted model validates a file is uploaded you might want to make use of the sample_key method
include CarrierWaveDirect::Test::Helpers
Factory.define :user |f|
f.email "some1@example.com"
f.key { sample_key(AvatarUploader.new) }
end
This will return a valid key based off your upload_dir and your extension_white_list
If you wanted to fake a download in the background you could do something like this
uploader = AvatarUploader.new
upload_path = find_upload_path
redirect_key = sample_key(:base => find_key, :filename => File.basename(upload_path))
uploader.key = redirect_key
download_url = uploader.direct_fog_url(:with_path => true)
# Register the download url and return the uploaded file in the body
FakeWeb.register_uri(:get, download_url, :body => File.open(upload_path))
The Active Record validations use the Rails i18n framework. Add these keys to your translations file:
en:
errors:
messages:
carrierwave_direct_filename_taken: filename was already taken
carrierwave_direct_upload_missing: upload is missing
carrierwave_direct_attachment_missing: attachment is missing
carrierwave_direct_filename_invalid: is invalid. Allowed file types are ${extension_white_list}
carrierwave_direct_remote_net_url_invalid: is invalid. Allowed file types are ${extension_white_list}. Allowed url schemes are ${url_scheme_white_list}
Pull requests are very welcome. Before submitting a pull request, please make sure that your changes are well tested.
gem install bundler
bundle install
You should now be able to run the tests
bundle exec rake
- cblunt (Chris Blunt) - Support for passing html options
- robyurkowski (Rob Yurkowski) - Fix deprecation warnings for Rails 3.2
- tylr (Tyler Love) - Bug fix