development.rb

PAPERCLIP_CONFIG = {}

initializer.rb

AMAZON_CONFIG = YAML.load_file("#{RAILS_ROOT}/config/amazon_s3.yml")[RAILS_ENV]

production.rb

PAPERCLIP_CONFIG = {
  :path => ":class/:attachment/:id/:style/:basename.:extension",
  :storage => :s3,
  :s3_credentials => AMAZON_CONFIG,
  :s3_permissions => 'public-read',
  :bucket => AMAZON_CONFIG['bucket'],
  :s3_host_alias => AMAZON_CONFIG['bucket'],
  :url => ":s3_alias_url"
}

user.rb

class User < ActiveRecord::Base
  
  has_attached_file :avatar, {
                      :url      => "/system/users/:attachment/:id/:style/:basename.:extension",
                      :path     => ":rails_root/public/system/users/:attachment/:id/:style/:basename.:extension",
                      :styles   => { :thumb => ['48x48#', :png], :large => ['125x125#', :png] },
                      :default_url => "/images/avatars/user/default_:style.jpg"
                    }.merge(PAPERCLIP_CONFIG)

end