module Technoweenie # :nodoc:
module AttachmentFu # :nodoc:
module Backends
# = AWS::S3 Storage Backend
#
# Enables use of {Amazon's Simple Storage Service}[http://aws.amazon.com/s3] as a storage mechanism
#
# == Requirements
#
# Requires the {AWS::S3 Library}[http://amazon.rubyforge.org] for S3 by Marcel Molina Jr. installed either
# as a gem or a as a Rails plugin.
#
# == Configuration
#
# Configuration is done via <tt>RAILS_ROOT/config/amazon_s3.yml</tt> and is loaded according to the <tt>RAILS_ENV</tt>.
# The minimum connection options that you must specify are a bucket name, your access key id and your secret access key.
# If you don't already have your access keys, all you need to sign up for the S3 service is an account at Amazon.
# You can sign up for S3 and get access keys by visiting http://aws.amazon.com/s3.
#
# Example configuration (RAILS_ROOT/config/amazon_s3.yml)
#
# development:
# bucket_name: appname_development
# access_key_id: <your key>
# secret_access_key: <your key>
#
# test:
# bucket_name: appname_test
# access_key_id: <your key>
# secret_access_key: <your key>
#
# production:
# bucket_name: appname
# access_key_id: <your key>
# secret_access_key: <your key>
#
# You can change the location of the config path by passing a full path to the :s3_config_path option.
#
# has_attachment :storage => :s3, :s3_config_path => (RAILS_ROOT + '/config/s3.yml')
#
# === Required configuration parameters
#
# * <tt>:access_key_id</tt> - The access key id for your S3 account. Provided by Amazon.
# * <tt>:secret_access_key</tt> - The secret access key for your S3 account. Provided by Amazon.
# * <tt>:bucket_name</tt> - A unique bucket name (think of the bucket_name as being like a database name).
#
# If any of these required arguments is missing, a MissingAccessKey exception will be raised from AWS::S3.
#
# == About bucket names
#
# Bucket names have to be globaly unique across the S3 system. And you can only have up to 100 of them,
# so it's a good idea to think of a bucket as being like a database, hence the correspondance in this
# implementation to the development, test, and production environments.
#
# The number of objects you can store in a bucket is, for all intents and purposes, unlimited.
#
# === Optional configuration parameters
#
# * <tt>:server</tt> - The server to make requests to. Defaults to <tt>s3.amazonaws.com</tt>.
# * <tt>:port</tt> - The port to the requests should be made on. Defaults to 80 or 443 if <tt>:use_ssl</tt> is set.
# * <tt>:use_ssl</tt> - If set to true, <tt>:port</tt> will be implicitly set to 443, unless specified otherwise. Defaults to false.
#
# == Usage
#
# To specify S3 as the storage mechanism for a model, set the acts_as_attachment <tt>:storage</tt> option to <tt>:s3</tt>.
#
# class Photo < ActiveRecord::Base
# has_attachment :storage => :s3
# end
#
# === Customizing the path
#
# By default, files are prefixed using a pseudo hierarchy in the form of <tt>:table_name/:id</tt>, which results
# in S3 urls that look like: http(s)://:server/:bucket_name/:table_name/:id/:filename with :table_name
# representing the customizable portion of the path. You can customize this prefix using the <tt>:path_prefix</tt>
# option:
#
# class Photo < ActiveRecord::Base
# has_attachment :storage => :s3, :path_prefix => 'my/custom/path'
# end
#
# Which would result in URLs like <tt>http(s)://:server/:bucket_name/my/custom/path/:id/:filename.</tt>
#
# === Permissions
#
# By default, files are stored on S3 with public access permissions. You can customize this using
# the <tt>:s3_access</tt> option to <tt>has_attachment</tt>. Available values are
# <tt>:private</tt>, <tt>:public_read_write</tt>, and <tt>:authenticated_read</tt>.
#
# === Other options
#
# Of course, all the usual configuration options apply, such as content_type and thumbnails:
#
# class Photo < ActiveRecord::Base
# has_attachment :storage => :s3, :content_type => ['application/pdf', :image], :resize_to => 'x50'
# has_attachment :storage => :s3, :thumbnails => { :thumb => [50, 50], :geometry => 'x50' }
# end
#
# === Accessing S3 URLs
#
# You can get an object's URL using the s3_url accessor. For example, assuming that for your postcard app
# you had a bucket name like 'postcard_world_development', and an attachment model called Photo:
#
# @postcard.s3_url # => http(s)://s3.amazonaws.com/postcard_world_development/photos/1/mexico.jpg
#
# The resulting url is in the form: http(s)://:server/:bucket_name/:table_name/:id/:file.
# The optional thumbnail argument will output the thumbnail's filename (if any).
#
# Additionally, you can get an object's base path relative to the bucket root using
# <tt>base_path</tt>:
#
# @photo.file_base_path # => photos/1
#
# And the full path (including the filename) using <tt>full_filename</tt>:
#
# @photo.full_filename # => photos/
#
# Niether <tt>base_path</tt> or <tt>full_filename</tt> include the bucket name as part of the path.
# You can retrieve the bucket name using the <tt>bucket_name</tt> method.
module S3Backend
class RequiredLibraryNotFoundError < StandardError; end
class ConfigFileNotFoundError < StandardError; end
def self.included(base) #:nodoc:
mattr_reader :bucket_name, :s3_config
begin
require 'aws/s3'
include AWS::S3
rescue LoadError
raise RequiredLibraryNotFoundError.new('AWS::S3 could not be loaded')
end
begin
@@s3_config_path = base.attachment_options[:s3_config_path] || (RAILS_ROOT + '/config/amazon_s3.yml')
@@s3_config = @@s3_config = YAML.load_file(@@s3_config_path)[RAILS_ENV].symbolize_keys
#rescue
# raise ConfigFileNotFoundError.new('File %s not found' % @@s3_config_path)
end
@@bucket_name = s3_config[:bucket_name]
Base.establish_connection!(
:access_key_id => s3_config[:access_key_id],
:secret_access_key => s3_config[:secret_access_key],
:server => s3_config[:server],
:port => s3_config[:port],
:use_ssl => s3_config[:use_ssl]
)
# Bucket.create(@@bucket_name)
base.before_update :rename_file
end
def self.protocol
@protocol ||= s3_config[:use_ssl] ? 'https://' : 'http://'
end
def self.hostname
@hostname ||= s3_config[:server] || AWS::S3::DEFAULT_HOST
end
def self.port_string
@port_string ||= (s3_config[:port].nil? || s3_config[:port] == (s3_config[:use_ssl] ? 443 : 80)) ? '' : ":#{s3_config[:port]}"
end
module ClassMethods
def s3_protocol
Technoweenie::AttachmentFu::Backends::S3Backend.protocol
end
def s3_hostname
Technoweenie::AttachmentFu::Backends::S3Backend.hostname
end
def s3_port_string
Technoweenie::AttachmentFu::Backends::S3Backend.port_string
end
end
# Overwrites the base filename writer in order to store the old filename
def filename=(value)
@old_filename = filename unless filename.nil? || @old_filename
write_attribute :filename, sanitize_filename(value)
end
# The attachment ID used in the full path of a file
def attachment_path_id
((respond_to?(:parent_id) && parent_id) || id).to_s
end
# The pseudo hierarchy containing the file relative to the bucket name
# Example: <tt>:table_name/:id</tt>
def base_path
File.join(attachment_options[:path_prefix], attachment_path_id)
end
# The full path to the file relative to the bucket name
# Example: <tt>:table_name/:id/:filename</tt>
def full_filename(thumbnail = nil)
File.join(base_path, thumbnail_name_for(thumbnail))
end
# All public objects are accessible via a GET request to the S3 servers. You can generate a
# url for an object using the s3_url method.
#
# @photo.s3_url
#
# The resulting url is in the form: <tt>http(s)://:server/:bucket_name/:table_name/:id/:file</tt> where
# the <tt>:server</tt> variable defaults to <tt>AWS::S3 URL::DEFAULT_HOST</tt> (s3.amazonaws.com) and can be
# set using the configuration parameters in <tt>RAILS_ROOT/config/amazon_s3.yml</tt>.
#
# The optional thumbnail argument will output the thumbnail's filename (if any).
def s3_url(thumbnail = nil)
File.join(s3_protocol + s3_hostname + s3_port_string, bucket_name, full_filename(thumbnail))
end
alias :public_filename :s3_url
# All private objects are accessible via an authenticated GET request to the S3 servers. You can generate an
# authenticated url for an object like this:
#
# @photo.authenticated_s3_url
#
# By default authenticated urls expire 5 minutes after they were generated.
#
# Expiration options can be specified either with an absolute time using the <tt>:expires</tt> option,
# or with a number of seconds relative to now with the <tt>:expires_in</tt> option:
#
# # Absolute expiration date (October 13th, 2025)
# @photo.authenticated_s3_url(:expires => Time.mktime(2025,10,13).to_i)
#
# # Expiration in five hours from now
# @photo.authenticated_s3_url(:expires_in => 5.hours)
#
# You can specify whether the url should go over SSL with the <tt>:use_ssl</tt> option.
# By default, the ssl settings for the current connection will be used:
#
# @photo.authenticated_s3_url(:use_ssl => true)
#
# Finally, the optional thumbnail argument will output the thumbnail's filename (if any):
#
# @photo.authenticated_s3_url('thumbnail', :expires_in => 5.hours, :use_ssl => true)
def authenticated_s3_url(*args)
thumbnail = args.first.is_a?(String) ? args.first : nil
options = args.last.is_a?(Hash) ? args.last : {}
S3Object.url_for(full_filename(thumbnail), bucket_name, options)
end
def create_temp_file
write_to_temp_file current_data
end
def current_data
S3Object.value full_filename, bucket_name
end
def s3_protocol
Technoweenie::AttachmentFu::Backends::S3Backend.protocol
end
def s3_hostname
Technoweenie::AttachmentFu::Backends::S3Backend.hostname
end
def s3_port_string
Technoweenie::AttachmentFu::Backends::S3Backend.port_string
end
protected
# Called in the after_destroy callback
def destroy_file
S3Object.delete full_filename, bucket_name
end
def rename_file
return unless @old_filename && @old_filename != filename
old_full_filename = File.join(base_path, @old_filename)
S3Object.rename(
old_full_filename,
full_filename,
bucket_name,
:access => attachment_options[:s3_access]
)
@old_filename = nil
true
end
def save_to_storage
if save_attachment?
S3Object.store(
full_filename,
(temp_path ? File.open(temp_path) : temp_data),
bucket_name,
:content_type => content_type,
:access => attachment_options[:s3_access]
)
end
@old_filename = nil
true
end
end
end
end
end
) is private.
