Build Robust & Production Quality Applications - Lesson 7: File Uploading with Carrierwave

Adding Carrierwave to your Application

1. Install gem Carrierwave-aws

2. Make sure you have ImageMagick installed locally

3. Run migration to remove current small/large image urls and add columns for images

4. Mount uploaders to video model

mount_uploader :large_cover, LargeCoverUploader
mount_uploader :small_cover, SmallCoverUploader

5. Create app/uploaders directory, add uploaders to folder:

#app/uploaders/large_cover_uploader.rb
class LargeCoverUploader < class LargeCoverUploader < CarrierWave::Uploader::Base
  include CarrierWave::MiniMagick

  version :large_version do
    process resize_to_fill: [665, 375]
  end
end

Note: That specifiying version is required since uploading the same file, although it is being resized for the large or small cover photo will cause it to be overidden.

You will also need to specificy the version in the views:

#videos/show.html.haml
%article.video
  .container
    .row
      .video_large_cover.col-sm-7.col-sm-offset-1
        = image_tag @video.large_cover.large_version.url, alt: "large video"

#app/uploaders/small_cover_uploader.rb
class SmallCoverUploader < CarrierWave::Uploader::Base
  include CarrierWave::MiniMagick

  process :resize_to_fill => [166, 236]
end

6. Create config/initializers/carrier_wave.rb

Add configuration based on docs

7. Follow this blog using S3 IAMs

8. Update the User Policy to include the following configurations:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "NotAction": "iam:*",
      "Resource": "*"
    }
  ]
}

9. Now you need to store your credentials in Rails Env variables. Follow this Tealeaf blogpost