Module: Lipsiadmin::Attachment::Storage::S3

Defined in:
lib/data_base/attachment/storage.rb

Overview

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 => 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.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(base) ⇒ Object 



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# File 'lib/data_base/attachment/storage.rb', line 122

def self.extended base
  require 'right_aws'
  base.instance_eval do
    @s3_credentials = parse_credentials(@options[:s3_credentials])
    @bucket         = @options[:bucket]         || @s3_credentials[:bucket]
    @s3_options     = @options[:s3_options]     || {}
    @s3_permissions = @options[:s3_permissions] || 'public-read'
    @s3_protocol    = @options[:s3_protocol]    || (@s3_permissions == 'public-read' ? 'http' : 'https')
    @s3_headers     = @options[:s3_headers]     || {}
    @url            = ":s3_path_url" unless @url.to_s.match(/^:s3.*url$/)
  end
  base.class.interpolations[:s3_path_url] = lambda do |attachment, style|
    "#{attachment.s3_protocol}://s3.amazonaws.com/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{^/}, "")}"
  end
  base.class.interpolations[:s3_domain_url] = lambda do |attachment, style|
    "#{attachment.s3_protocol}://#{attachment.bucket_name}.s3.amazonaws.com/#{attachment.path(style).gsub(%r{^/}, "")}"
  end
  ActiveRecord::Base.logger.info("[Attachment] S3 Storage Initalized.")
end

Instance Method Details

#bucket_name ⇒ Object 



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# File 'lib/data_base/attachment/storage.rb', line 152

def bucket_name
  @bucket
end

#exists?(style = default_style) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_base/attachment/storage.rb', line 161

def exists?(style = default_style)
  s3_bucket.key(path(style)) ? true : false
end

#flush_deletes ⇒ Object

:nodoc:



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# File 'lib/data_base/attachment/storage.rb', line 191

def flush_deletes #:nodoc:
  logger.info("[Attachment] Writing files for #{name}")
  @queued_for_delete.each do |path|
    begin
      logger.info("[Attachment] -> #{path}")
      if file = s3_bucket.key(path)
        file.delete
      end
    rescue RightAws::AwsError
      # Ignore this.
    end
  end
  @queued_for_delete = []
end

#flush_writes ⇒ Object

:nodoc:



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# File 'lib/data_base/attachment/storage.rb', line 176

def flush_writes #:nodoc:
  logger.info("[Attachment] Writing files for #{name}")
  @queued_for_write.each do |style, file|
    begin
      logger.info("[Attachment] -> #{path(style)}")
      key = s3_bucket.key(path(style))
      key.data = file
      key.put(nil, @s3_permissions, {'Content-type' => instance_read(:content_type)}.merge(@s3_headers))
    rescue RightAws::AwsError => e
      raise
    end
  end
  @queued_for_write = {}
end

#parse_credentials(creds) ⇒ Object 



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# File 'lib/data_base/attachment/storage.rb', line 156

def parse_credentials(creds)
  creds = find_credentials(creds).stringify_keys
  (creds[ENV['RAILS_ENV']] || creds).symbolize_keys
end

#s3 ⇒ Object 



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# File 'lib/data_base/attachment/storage.rb', line 142

def s3
  @s3 ||= RightAws::S3.new(@s3_credentials[:access_key_id],
                           @s3_credentials[:secret_access_key],
                           @s3_options)
end

#s3_bucket ⇒ Object 



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# File 'lib/data_base/attachment/storage.rb', line 148

def s3_bucket
  @s3_bucket ||= s3.bucket(@bucket, true, @s3_permissions)
end

#s3_protocol ⇒ Object 



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# File 'lib/data_base/attachment/storage.rb', line 165

def s3_protocol
  @s3_protocol
end

#to_file(style = default_style) ⇒ Object Also known as: to_io

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



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# File 'lib/data_base/attachment/storage.rb', line 171

def to_file(style = default_style)
  @queued_for_write[style] || s3_bucket.key(path(style))
end