Module Paperclip::Storage::S3
In: lib/dm-paperclip/storage.rb

Amazon‘s S3 file hosting service is a scalable, easy place to store files for distribution. You can find out more about it at aws.amazon.com/s3 There are a few S3-specific options for has_attached_file:

  • +s3_credentials+: Takes a path, a File, or a Hash. The path (or File) must point to a YAML file containing the access_key_id and secret_access_key that Amazon gives you. You can ‘environment-space’ this just like you do to your database.yml file, so different environments can use different accounts:
      development:
        access_key_id: 123...
        secret_access_key: 123...
      test:
        access_key_id: abc...
        secret_access_key: abc...
      production:
        access_key_id: 456...
        secret_access_key: 456...
    

    This is not required, however, and the file may simply look like this:

      access_key_id: 456...
      secret_access_key: 456...
    

    In which case, those access keys will be used in all environments. You can also put your bucket name in this file, instead of adding it to the code directly. This is useful when you want the same account but a different bucket for development versus production.

  • +s3_permissions+: This is a String that should be one of the "canned" access policies that S3 provides (more information can be found here: docs.amazonwebservices.com/AmazonS3/2006-03-01/RESTAccessPolicy.html#RESTCannedAccessPolicies) The default for Paperclip is :public_read.
  • +s3_protocol+: The protocol for the URLs generated to your S3 assets. Can be either ‘http’ or ‘https’. Defaults to ‘http’ when your :s3_permissions are :public_read (the default), and ‘https’ when your :s3_permissions are anything else.
  • +s3_headers+: A hash of headers such as {‘Expires’ => 1.year.from_now.httpdate}
  • bucket: This is the name of the S3 bucket that will store your files. Remember that the bucket must be unique across all of Amazon S3. If the bucket does not exist Paperclip will attempt to create it. The bucket name will not be interpolated. You can define the bucket as a Proc if you want to determine it‘s name at runtime. Paperclip will call that Proc with attachment as the only argument.
  • +s3_host_alias+: The fully-qualified domain name (FQDN) that is the alias to the S3 domain of your bucket. Used with the :s3_alias_url url interpolation. See the link in the url entry for more information about S3 domains and buckets.
  • url: There are three options for the S3 url. You can choose to have the bucket‘s name placed domain-style (bucket.s3.amazonaws.com) or path-style (s3.amazonaws.com/bucket). Lastly, you can specify a CNAME (which requires the CNAME to be specified as :s3_alias_url. You can read more about CNAMEs and S3 at docs.amazonwebservices.com/AmazonS3/latest/index.html?VirtualHosting.html Normally, this won‘t matter in the slightest and you can leave the default (which is path-style, or :s3_path_url). But in some cases paths don‘t work and you need to use the domain-style (:s3_domain_url). Anything else here will be treated like path-style. NOTE: If you use a CNAME for use with CloudFront, you can NOT specify https as your :s3_protocol; This is *not supported* by S3/CloudFront. Finally, when using the host alias, the :bucket parameter is ignored, as the hostname is used as the bucket name by S3.
  • path: This is the key under the bucket in which the file will be stored. The URL will be constructed from the bucket and the path. This is what you will want to interpolate. Keys should be unique, like filenames, and despite the fact that S3 (strictly speaking) does not support directories, you can still use a / to separate parts of your file name.

Methods

Public Class methods

[Source]

     # File lib/dm-paperclip/storage.rb, line 129
129:       def self.extended base
130:         begin
131:           require 'aws/s3'
132:         rescue LoadError => e
133:           e.message << " (You may need to install the aws-s3 gem)"
134:           raise e
135:         end
136: 
137:         base.instance_eval do
138:           @s3_credentials = parse_credentials(@options[:s3_credentials])
139:           @bucket         = @options[:bucket]         || @s3_credentials[:bucket]
140:           @bucket         = @bucket.call(self) if @bucket.is_a?(Proc)
141:           @s3_options     = @options[:s3_options]     || {}
142:           @s3_permissions = @options[:s3_permissions] || :public_read
143:           @s3_protocol    = @options[:s3_protocol]    || (@s3_permissions == :public_read ? 'http' : 'https')
144:           @s3_headers     = @options[:s3_headers]     || {}
145:           @s3_host_alias  = @options[:s3_host_alias]
146:           @url            = ":s3_path_url" unless @url.to_s.match(/^:s3.*url$/)
147:           AWS::S3::Base.establish_connection!( @s3_options.merge(
148:             :access_key_id => @s3_credentials[:access_key_id],
149:             :secret_access_key => @s3_credentials[:secret_access_key]
150:           ))
151:         end
152:         Paperclip.interpolates(:s3_alias_url) do |attachment, style|
153:           "#{attachment.s3_protocol}://#{attachment.s3_host_alias}/#{attachment.path(style).gsub(%r{^/}, "")}"
154:         end
155:         Paperclip.interpolates(:s3_path_url) do |attachment, style|
156:           "#{attachment.s3_protocol}://s3.amazonaws.com/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
157:         end
158:         Paperclip.interpolates(:s3_domain_url) do |attachment, style|
159:           "#{attachment.s3_protocol}://#{attachment.bucket_name}.s3.amazonaws.com/#{attachment.path(style).gsub(%r{^/}, "")}"
160:         end
161:       end

Public Instance methods

[Source]

     # File lib/dm-paperclip/storage.rb, line 167
167:       def bucket_name
168:         @bucket
169:       end

[Source]

     # File lib/dm-paperclip/storage.rb, line 190
190:       def exists?(style = default_style)
191:         if original_filename
192:           AWS::S3::S3Object.exists?(path(style), bucket_name)
193:         else
194:           false
195:         end
196:       end

[Source]

     # File lib/dm-paperclip/storage.rb, line 163
163:       def expiring_url(time = 3600)
164:         AWS::S3::S3Object.url_for(path, bucket_name, :expires_in => time )
165:       end

[Source]

     # File lib/dm-paperclip/storage.rb, line 175
175:       def parse_credentials creds
176:         creds = find_credentials(creds).to_mash.stringify_keys!
177:         if defined? Merb && Merb.respond_to?(:env)
178:           (creds[Merb.env] || creds).symbolize_keys
179:         elsif defined? RAILS_ENV
180:           (creds[RAILS_ENV] || creds).symbolize_keys
181:         elsif defined? Rails && Rails.respond_to(:env)
182:           (creds[Rails.env] || creds).symbolize_keys
183:         elsif defined? RACK_ENV
184:           (creds[RACK_ENV] || creds).symbolize_keys
185:         else
186:           creds.symbolize_keys
187:         end
188:       end

[Source]

     # File lib/dm-paperclip/storage.rb, line 171
171:       def s3_host_alias
172:         @s3_host_alias
173:       end

[Source]

     # File lib/dm-paperclip/storage.rb, line 198
198:       def s3_protocol
199:         @s3_protocol
200:       end

Returns representation of the data of the file assigned to the given style, in the format most representative of the current storage.

[Source]

     # File lib/dm-paperclip/storage.rb, line 204
204:       def to_file style = default_style
205:         return @queued_for_write[style] if @queued_for_write[style]
206:         file = Tempfile.new(path(style))
207:         file.write(AWS::S3::S3Object.value(path(style), bucket_name))
208:         file.rewind
209:         return file
210:       end

[Validate]