Until now, I have been using Amazon S3 for storing users' files.

All what has been needed to do here was:

1. specify Amazon S3 credentials to the bucket
2. add `'aws-sdk'` gem to the Gemfile
3. and in the model:

---

```
  has_attached_file :avatar, 
                    :styles => { :big => "100x100#", :thumb => "25x25#" },
                    :storage => :s3,
                    :s3_credentials => "#{Rails.root}/config/s3.yml",
                    :path => ":rails_root/public/users/:id/:style/:basename.:extension",
                    :url => "/users/:id/:style/:basename.:extension"

```

To set the Amazon S3 adapter. That was all.

But how to set up Google cloud engine? So far I found only the [fog gem](http://fog.io/storage/) , which I could use.

However, how should I configure the model to automatically store all uploaded files on Google servers?