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 Attachment 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 Attachment will attempt to create it. The bucket name will not be interpolated.
- url: There are two 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). 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.
- 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
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# File lib/data_base/attachment/storage.rb, line 122
122: def self.extended base
123: require 'right_aws'
124: base.instance_eval do
125: @s3_credentials = parse_credentials(@options[:s3_credentials])
126: @bucket = @options[:bucket] || @s3_credentials[:bucket]
127: @s3_options = @options[:s3_options] || {}
128: @s3_permissions = @options[:s3_permissions] || 'public-read'
129: @s3_protocol = @options[:s3_protocol] || (@s3_permissions == 'public-read' ? 'http' : 'https')
130: @s3_headers = @options[:s3_headers] || {}
131: @url = ":s3_path_url" unless @url.to_s.match(/^:s3.*url$/)
132: end
133: base.class.interpolations[:s3_path_url] = lambda do |attachment, style|
134: "#{attachment.s3_protocol}://s3.amazonaws.com/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
135: end
136: base.class.interpolations[:s3_domain_url] = lambda do |attachment, style|
137: "#{attachment.s3_protocol}://#{attachment.bucket_name}.s3.amazonaws.com/#{attachment.path(style).gsub(%r{^/}, "")}"
138: end
139: ActiveRecord::Base.logger.info("[Attachment] S3 Storage Initalized.")
140: end
Public Instance methods
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# File lib/data_base/attachment/storage.rb, line 152
152: def bucket_name
153: @bucket
154: end
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# File lib/data_base/attachment/storage.rb, line 161
161: def exists?(style = default_style)
162: s3_bucket.key(path(style)) ? true : false
163: end
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# File lib/data_base/attachment/storage.rb, line 156
156: def parse_credentials(creds)
157: creds = find_credentials(creds).stringify_keys
158: (creds[ENV['RAILS_ENV']] || creds).symbolize_keys
159: end
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# File lib/data_base/attachment/storage.rb, line 142
142: def s3
143: @s3 ||= RightAws::S3.new(@s3_credentials[:access_key_id],
144: @s3_credentials[:secret_access_key],
145: @s3_options)
146: end
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# File lib/data_base/attachment/storage.rb, line 148
148: def s3_bucket
149: @s3_bucket ||= s3.bucket(@bucket, true, @s3_permissions)
150: end
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# File lib/data_base/attachment/storage.rb, line 165
165: def s3_protocol
166: @s3_protocol
167: end
Returns representation of the data of the file assigned to the given style, in the format most representative of the current storage.
This method is also aliased as
to_io
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# File lib/data_base/attachment/storage.rb, line 171
171: def to_file(style = default_style)
172: @queued_for_write[style] || s3_bucket.key(path(style))
173: end
Alias for to_file