CarrierWave_Direct gem: Keep current directory structure on S3 - ruby-on-rails

Question

so I have a site already in production using the carrierwave gem with images stored on amazon s3. my uploader uses the store_dir method to specify a particular structure to put in processed images.
well, now in my dev environment I've added the carrierwave_direct gem to start uploading directly to S3. The problem is this gem completely overrides the store_dir and filename defaults in my uploader. I can't push my fully working uploader live because all my old image links will be broken.
it's my understanding that the CWdirect gem would upload a raw image file to a "temp" directory on S3, then S3 responds and gives you a key variable so you can grab this file and process it as you see fit. so, should i be using a completely separate image uploader class in carrierwave to process the images and place them in the correct folders? meaning I'll have one uploader dedicated to carrierwave_direct that uploads wherever this gem seems to want to upload to; and I'll use another uploader.rb class linked to my real model that keeps my current store_dir and filename structure?
In any case, my basic question is, how can I use CarrierWave_Direct gem if I already have CW running in production with images in a specific folder structure?

Answer 1

Ok, so I did figure out how to do this and I'll explain below. My hunch was correct to use two different CarrierWave uploader classes--one class dedicated to uploading to S3 (using CarrierWave_Direct gem), and a second class used only for image processing (the class I was already using in production). I'll try and post relevant code below but if anyone has questions let me know. I'm unsure why I haven't seen others using separate classes like this but it seems to work for me.
My image Uploader class app\uploaders\image_uploader.rb utilizing carrierwave_direct gem:
class ImageUploader < CarrierWave::Uploader::Base
include CarrierWaveDirect::Uploader
include ActiveModel::Conversion
extend ActiveModel::Naming
include CarrierWave::MimeTypes
process :set_content_type
# Add a white list of extensions which are allowed to be uploaded.
# For images you might use something like this:
def extension_white_list
%w(jpg jpeg gif png)
end
# Include the Sprockets helpers for Rails 3.1+ asset pipeline compatibility:
include Sprockets::Helpers::RailsHelper
include Sprockets::Helpers::IsolatedHelper
# Override the directory where uploaded files will be stored.
# CarrierWaveDirect::Uploader puts raw uploaded files in this directory on S3 as a first step
def store_dir
"unprocessed_uploads"
end
end
**notice there's no processing being done in this class
My image PROCESSING class app\uploaders\image_processor.rb (what was already in place in production):
class ImageProcessor < CarrierWave::Uploader::Base
# Include RMagick or MiniMagick support:
# include CarrierWave::RMagick
include CarrierWave::MiniMagick
include CarrierWave::MimeTypes
process :set_content_type
# Include the Sprockets helpers for Rails 3.1+ asset pipeline compatibility:
include Sprockets::Helpers::RailsHelper
include Sprockets::Helpers::IsolatedHelper
# Choose what kind of storage to use for this uploader:
storage :fog
# Override the directory where uploaded files will be stored.
# This is a sensible default for uploaders that are meant to be mounted:
def store_dir
"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
# "uploads/#{model.class.to_s.underscore}/path/#{model.id}"
end
# Provide a default URL as a default if there hasn't been a file uploaded:
def default_url
"logos/" + [version_name, "default.png"].compact.join('_')
end
# Process files fetched from S3 after they are uploaded:
def make_thumbnail(width, height)
# uses MiniMagick classes to get a square, centered thumbnail image
manipulate! do |img|
if img[:width] < img[:height]
remove = ((img[:height] - img[:width])/2).round
img.shave("0x#{remove}")
elsif img[:width] > img[:height]
remove = ((img[:width] - img[:height])/2).round
img.shave("#{remove}x0")
end
img.resize("#{width}x#{height}")
img
end
end
# Create different versions of your uploaded files:
# the process statement below isn't defined within a version block on purpose--this means the ORIGINAL uploaded photo is constrained to 1050 pics
process :resize_to_limit => [1050, 1050]
process :quality => 85 # this reduces filesize greatly and saves space
version :thumb do
process :make_thumbnail => [100, 100]
process :quality => 85 # this reduces filesize greatly and saves space
end
version :big_thumb do
process :make_thumbnail => [350, 350]
process :quality => 85 # this reduces filesize greatly and saves space
end
# Add a white list of extensions which are allowed to be uploaded.
# For images you might use something like this:
def extension_white_list
%w(jpg jpeg gif png)
end
# Override the filename of the uploaded files:
# Avoid using model.id or version_name here, see uploader/store.rb for details.
def filename
if original_filename
if model && model.read_attribute(:image).present?
model.read_attribute(:image)
else
"#{secure_token}.#{file.extension}"
end
end
end
protected
def secure_token
var = :"##{mounted_as}_secure_token"
model.instance_variable_get(var) or model.instance_variable_set(var, SecureRandom.uuid)
end
end
My Photo model (summarized):
class Photo < ActiveRecord::Base
mount_uploader :image, ImageProcessor
def save_and_process_image(options = {})
s3_unprocessed_image_url = self.image.asset_host + '/' + self.key
# this next line downloads the image from S3
# and this save line below will process the image and reupload to S3 according to ImageProcessor settings
self.remote_image_url = s3_unprocessed_image_url
save
end
end
I also have Photo controller and view code available, if ya'll want it let me know. Basically I use the ImageUploader class to do the initial upload to S3 to a folder called unprocessed_uploads. Then S3 responds with a key field in the URL which I pass on to ImageProcessor class--this is attached to a Photo and processes the thumbnail and other images then re-uploads them to my uploads folder on S3.
This separation meant i didn't need to change my current folder structure on S3 when adding the carrierwave_direct gem. Hope this helps others. Let me know if you need more code I'm kind of tired of typing :)
UPDATE--Adding more code:
Photos Controller:
class PhotosController < ApplicationController
def index
#photos = #photos.sort_by(&:created_at)
#uploader = ImageUploader.new
#uploader.success_action_redirect = new_tank_photo_url(#tank)
respond_to do |format|
format.html # index.html.erb
format.json { render json: #photos }
end
end
def create
respond_to do |format|
if #photo.save_and_process_image
format.html { redirect_to tank_photos_path(#tank), notice: 'Photo uploaded successfully and is being processed...' }
format.json { render json: #photo, status: :created, location: #photo }
else
format.html { render :new }
format.json { render json: #photo.errors, status: :unprocessable_entity }
end
end
end
Photos Index view, the form with the Upload button:
<%= direct_upload_form_for #uploader, :html => {:class => "form-inline"} do |f| %>
<%= f.file_field :image %>
<%= f.submit "Upload", :class => "btn btn-primary btn-medium" %>
<% end %>
So with the above view/controller code added, here is a summary of the steps taken. Please note the difference between the ImageUploader class and the ImageProcessor class:
In my Photos Controller I create the #uploader variable which is of class ImageUploader--this means that images submitted in my index/view form which uses #uploader will upload the image to a "temp" folder--Since this uses the ImageUploader class then no processing is done when this image is uploaded (yet).
When the user clicks "Upload" button on the form, the Photo>>create action is called. This action calls #photo.save_and_process_image -- look at the model to see that this method actually grabs the recently uploaded image from the S3 'temp' folder, processes it, then re-uploads the processed images to their final destination. This is all possible because my Photo model is linked to the ImageProcessor class, which does the processing/uploading. It's not linked to the separate ImageUploader class.
Hope this helps explain what i have going on