Paperclip defaults for Amazon S3 virtual hosted-style requests

December 7, 2012. David Anguita Posted in Amazon , S3 , AWS , Rails , Paperclip

Paperclip is a great gem for adding file attachments to your Rails models. It ships with some storage adapters including Amazon S3 but the documentation isn’t totally clear for virtual hosted-style requests.

If you need to use classic path-style requests like http://s3.amazonaws.com/yourbucket, add these defaults to your environment file:

# config/environments/production.rb

config.paperclip_defaults = {
  :storage => :s3,
  :s3_credentials => {
    :bucket => ENV['AWS_BUCKET'],
    :access_key_id => ENV['AWS_ACCESS_KEY_ID'],
    :secret_access_key => ENV['AWS_SECRET_ACCESS_KEY']
  }
}

Otherwise, if you need to use virtual hosted-style requests like http://yourbucket.s3.amazonaws.com, you must specify the path and url options:

# config/environments/production.rb

config.paperclip_defaults = {
  :storage => :s3,
  :url => ":s3_domain_url",
  :path => ":class/:id.:style.:extension",
  :s3_credentials => {
    :bucket => ENV['AWS_BUCKET'],
    :access_key_id => ENV['AWS_ACCESS_KEY_ID'],
    :secret_access_key => ENV['AWS_SECRET_ACCESS_KEY']
  }
}

Important notes

For now (3.3.1) you will get a Paperclip::InfiniteInterpolationError exception if the path option is not specified.
The value of the url option must be ":s3_domain_url" as a string, not as a symbol.
The path option is fully customizable. The shown pattern will produce filepaths like http://yourbucket.s3.amazonaws.com/images/1.thumb.png.

References

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