Module: Paperclip::Storage::S3

Defined in:
lib/paperclip/storage/s3.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

To use Paperclip with S3, include the aws-sdk gem in your Gemfile:

gem 'aws-sdk'

There are a few S3-specific options for has_attached_file:

  • s3_credentials: Takes a path, a File, a Hash or a Proc. 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. When using a Proc it provides a single parameter which is the attachment itself. A method #instance is available on the attachment which will take you back to your code. eg.

    class User
      has_attached_file :download,
                        :storage => :s3,
                        :s3_credentials => Proc.new{|a| a.instance.s3_credentials }
    
      def s3_credentials
        {:bucket => "xxx", :access_key_id => "xxx", :secret_access_key => "xxx"}
      end
    end
  • 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.aws.amazon.com/AmazonS3/latest/dev/ACLOverview.html) The default for Paperclip is :public_read.

    You can set permission on a per style bases by doing the following:

    :s3_permissions => {
      :original => :private
    }

    Or globally:

    :s3_permissions => :private
  • s3_protocol: The protocol for the URLs generated to your S3 assets. Can be either 'http', 'https', or an empty string to generate protocol-relative URLs. 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 or a Proc. You may specify a hash such as => 1.year.from_now.httpdate. If you use a Proc, headers are determined at runtime. Paperclip will call that Proc with attachment as the only argument. Can be defined both globally and within a style-specific hash.

  • 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 four 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). You can also 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.

    Notes:

    • The value of this option is a string, not a symbol. right: ":s3_domain_url" wrong: :s3_domain_url

    • 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. The fourth option for the S3 url is :asset_host, which uses Rails' built-in asset_host settings.

    • To get the full url from a paperclip'd object, use the image_path helper; this is what image_tag uses to generate the url for an img tag.

  • 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.

  • s3_host_name: If you are using your bucket in Tokyo region etc, write host_name.

  • s3_metadata: These key/value pairs will be stored with the object. This option works by prefixing each key with “x-amz-meta-” before sending it as a header on the object upload request. Can be defined both globally and within a style-specific hash.

  • s3_storage_class: If this option is set to :reduced_redundancy, the object will be stored using Reduced Redundancy Storage. RRS enables customers to reduce their costs by storing non-critical, reproducible data at lower levels of redundancy than Amazon S3's standard storage.

    You can set storage class on a per style bases by doing the following:

    :s3_storage_class => {
      :thumb => :reduced_reduncancy
    }

    Or globally:

    :s3_storage_class => :reduced_redundancy

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(base) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 114

def self.extended base
  begin
    require 'aws-sdk'
  rescue LoadError => e
    e.message << " (You may need to install the aws-sdk gem)"
    raise e
  end unless defined?(AWS::Core)

  # Overriding log formatter to make sure it return a UTF-8 string
  if defined?(AWS::Core::LogFormatter)
    AWS::Core::LogFormatter.class_eval do
      def summarize_hash(hash)
        hash.map { |key, value| ":#{key}=>#{summarize_value(value)}".force_encoding('UTF-8') }.sort.join(',')
      end
    end
  elsif defined?(AWS::Core::ClientLogging)
    AWS::Core::ClientLogging.class_eval do
      def sanitize_hash(hash)
        hash.map { |key, value| "#{sanitize_value(key)}=>#{sanitize_value(value)}".force_encoding('UTF-8') }.sort.join(',')
      end
    end
  end

  base.instance_eval do
    @s3_options     = @options[:s3_options]     || {}
    @s3_permissions = set_permissions(@options[:s3_permissions])
    @s3_protocol    = @options[:s3_protocol]    ||
      Proc.new do |style, attachment|
        permission  = (@s3_permissions[style.to_s.to_sym] || @s3_permissions[:default])
        permission  = permission.call(attachment, style) if permission.respond_to?(:call)
        (permission == :public_read) ? 'http' : 'https'
      end
    @s3_metadata = @options[:s3_metadata] || {}
    @s3_headers = {}
    merge_s3_headers(@options[:s3_headers], @s3_headers, @s3_metadata)

    @s3_storage_class = set_storage_class(@options[:s3_storage_class])

    @s3_server_side_encryption = :aes256
    if @options[:s3_server_side_encryption].blank?
      @s3_server_side_encryption = false
    end
    if @s3_server_side_encryption
      @s3_server_side_encryption = @options[:s3_server_side_encryption]
    end

    unless @options[:url].to_s.match(/\A:s3.*url\Z/) || @options[:url] == ":asset_host"
      @options[:path] = path_option.gsub(/:url/, @options[:url]).gsub(/\A:rails_root\/public\/system/, '')
      @options[:url]  = ":s3_path_url"
    end
    @options[:url] = @options[:url].inspect if @options[:url].is_a?(Symbol)

    @http_proxy = @options[:http_proxy] || nil
  end

  Paperclip.interpolates(:s3_alias_url) do |attachment, style|
    "#{attachment.s3_protocol(style, true)}//#{attachment.s3_host_alias}/#{attachment.path(style).gsub(%r{\A/}, "")}"
  end unless Paperclip::Interpolations.respond_to? :s3_alias_url
  Paperclip.interpolates(:s3_path_url) do |attachment, style|
    "#{attachment.s3_protocol(style, true)}//#{attachment.s3_host_name}/#{attachment.bucket_name}/#{attachment.path(style).gsub(%r{\A/}, "")}"
  end unless Paperclip::Interpolations.respond_to? :s3_path_url
  Paperclip.interpolates(:s3_domain_url) do |attachment, style|
    "#{attachment.s3_protocol(style, true)}//#{attachment.bucket_name}.#{attachment.s3_host_name}/#{attachment.path(style).gsub(%r{\A/}, "")}"
  end unless Paperclip::Interpolations.respond_to? :s3_domain_url
  Paperclip.interpolates(:asset_host) do |attachment, style|
    "#{attachment.path(style).gsub(%r{\A/}, "")}"
  end unless Paperclip::Interpolations.respond_to? :asset_host
end

Instance Method Details

#bucket_nameObject



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# File 'lib/paperclip/storage/s3.rb', line 215

def bucket_name
  @bucket = @options[:bucket] || s3_credentials[:bucket]
  @bucket = @bucket.call(self) if @bucket.respond_to?(:call)
  @bucket or raise ArgumentError, "missing required :bucket option"
end

#copy_to_local_file(style, local_dest_path) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 394

def copy_to_local_file(style, local_dest_path)
  log("copying #{path(style)} to local file #{local_dest_path}")
  ::File.open(local_dest_path, 'wb') do |local_file|
    s3_object(style).read do |chunk|
      local_file.write(chunk)
    end
  end
rescue AWS::Errors::Base => e
  warn("#{e} - cannot copy #{path(style)} to local file #{local_dest_path}")
  false
end

#create_bucketObject



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# File 'lib/paperclip/storage/s3.rb', line 326

def create_bucket
  s3_interface.buckets.create(bucket_name)
end

#exists?(style = default_style) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/paperclip/storage/s3.rb', line 295

def exists?(style = default_style)
  if original_filename
    s3_object(style).exists?
  else
    false
  end
rescue AWS::Errors::Base => e
  false
end

#expiring_url(time = 3600, style_name = default_style) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 183

def expiring_url(time = 3600, style_name = default_style)
  if path(style_name)
    base_options = { :expires => time, :secure => use_secure_protocol?(style_name) }
    s3_object(style_name).url_for(:read, base_options.merge(s3_url_options)).to_s
  else
    url(style_name)
  end
end

#flush_deletesObject

:nodoc:



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# File 'lib/paperclip/storage/s3.rb', line 382

def flush_deletes #:nodoc:
  @queued_for_delete.each do |path|
    begin
      log("deleting #{path}")
      s3_bucket.objects[path.sub(%r{\A/},'')].delete
    rescue AWS::Errors::Base => e
      # Ignore this.
    end
  end
  @queued_for_delete = []
end

#flush_writesObject

:nodoc:



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# File 'lib/paperclip/storage/s3.rb', line 330

def flush_writes #:nodoc:
  @queued_for_write.each do |style, file|
  retries = 0
    begin
      log("saving #{path(style)}")
      acl = @s3_permissions[style] || @s3_permissions[:default]
      acl = acl.call(self, style) if acl.respond_to?(:call)
      write_options = {
        :content_type => file.content_type,
        :acl => acl
      }

      # add storage class for this style if defined
      storage_class = s3_storage_class(style)
      write_options.merge!(:storage_class => storage_class) if storage_class

      if @s3_server_side_encryption
        write_options[:server_side_encryption] = @s3_server_side_encryption
      end

      style_specific_options = styles[style]

      if style_specific_options
        merge_s3_headers( style_specific_options[:s3_headers], @s3_headers, @s3_metadata) if style_specific_options[:s3_headers]
        @s3_metadata.merge!(style_specific_options[:s3_metadata]) if style_specific_options[:s3_metadata]
      end

      write_options[:metadata] = @s3_metadata unless @s3_metadata.empty?
      write_options.merge!(@s3_headers)

      s3_object(style).write(file, write_options)
    rescue AWS::S3::Errors::NoSuchBucket
      create_bucket
      retry
    rescue AWS::S3::Errors::SlowDown
      retries += 1
      if retries <= 5
        sleep((2 ** retries) * 0.5)
        retry
      else
        raise
      end
    ensure
      file.rewind
    end
  end

  after_flush_writes # allows attachment to clean up temp files

  @queued_for_write = {}
end

#http_proxy_hostObject



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# File 'lib/paperclip/storage/s3.rb', line 262

def http_proxy_host
  using_http_proxy? ? @http_proxy[:host] : nil
end

#http_proxy_passwordObject



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# File 'lib/paperclip/storage/s3.rb', line 274

def http_proxy_password
  using_http_proxy? ? @http_proxy[:password] : nil
end

#http_proxy_portObject



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# File 'lib/paperclip/storage/s3.rb', line 266

def http_proxy_port
  using_http_proxy? ? @http_proxy[:port] : nil
end

#http_proxy_userObject



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# File 'lib/paperclip/storage/s3.rb', line 270

def http_proxy_user
  using_http_proxy? ? @http_proxy[:user] : nil
end

#obtain_s3_instance_for(options) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 245

def obtain_s3_instance_for(options)
  instances = (Thread.current[:paperclip_s3_instances] ||= {})
  instances[options] ||= AWS::S3.new(options)
end

#parse_credentials(creds) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 288

def parse_credentials creds
  creds = creds.respond_to?('call') ? creds.call(self) : creds
  creds = find_credentials(creds).stringify_keys
  env = Object.const_defined?(:Rails) ? Rails.env : nil
  (creds[env] || creds).symbolize_keys
end

#s3_bucketObject



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# File 'lib/paperclip/storage/s3.rb', line 250

def s3_bucket
  @s3_bucket ||= s3_interface.buckets[bucket_name]
end

#s3_credentialsObject



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# File 'lib/paperclip/storage/s3.rb', line 192

def s3_credentials
  @s3_credentials ||= parse_credentials(@options[:s3_credentials])
end

#s3_host_aliasObject



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# File 'lib/paperclip/storage/s3.rb', line 203

def s3_host_alias
  @s3_host_alias = @options[:s3_host_alias]
  @s3_host_alias = @s3_host_alias.call(self) if @s3_host_alias.respond_to?(:call)
  @s3_host_alias
end

#s3_host_nameObject



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# File 'lib/paperclip/storage/s3.rb', line 196

def s3_host_name
  host_name = @options[:s3_host_name]
  host_name = host_name.call(self) if host_name.is_a?(Proc)

  host_name || s3_credentials[:s3_host_name] || "s3.amazonaws.com"
end

#s3_interfaceObject



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# File 'lib/paperclip/storage/s3.rb', line 221

def s3_interface
  @s3_interface ||= begin
    config = { :s3_endpoint => s3_host_name }

    if using_http_proxy?

      proxy_opts = { :host => http_proxy_host }
      proxy_opts[:port] = http_proxy_port if http_proxy_port
      if http_proxy_user
        userinfo = http_proxy_user.to_s
        userinfo += ":#{http_proxy_password}" if http_proxy_password
        proxy_opts[:userinfo] = userinfo
      end
      config[:proxy_uri] = URI::HTTP.build(proxy_opts)
    end

    [:access_key_id, :secret_access_key, :credential_provider].each do |opt|
      config[opt] = s3_credentials[opt] if s3_credentials[opt]
    end

    obtain_s3_instance_for(config.merge(@s3_options))
  end
end

#s3_object(style_name = default_style) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 254

def s3_object style_name = default_style
  s3_bucket.objects[path(style_name).sub(%r{\A/},'')]
end

#s3_permissions(style = default_style) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 305

def s3_permissions(style = default_style)
  s3_permissions = @s3_permissions[style] || @s3_permissions[:default]
  s3_permissions = s3_permissions.call(self, style) if s3_permissions.respond_to?(:call)
  s3_permissions
end

#s3_protocol(style = default_style, with_colon = false) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 315

def s3_protocol(style = default_style, with_colon = false)
  protocol = @s3_protocol
  protocol = protocol.call(style, self) if protocol.respond_to?(:call)

  if with_colon && !protocol.empty?
    "#{protocol}:"
  else
    protocol.to_s
  end
end

#s3_storage_class(style = default_style) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 311

def s3_storage_class(style = default_style)
  @s3_storage_class[style] || @s3_storage_class[:default]
end

#s3_url_optionsObject



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# File 'lib/paperclip/storage/s3.rb', line 209

def s3_url_options
  s3_url_options = @options[:s3_url_options] || {}
  s3_url_options = s3_url_options.call(instance) if s3_url_options.respond_to?(:call)
  s3_url_options
end

#set_permissions(permissions) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 278

def set_permissions permissions
  permissions = { :default => permissions } unless permissions.respond_to?(:merge)
  permissions.merge :default => (permissions[:default] || :public_read)
end

#set_storage_class(storage_class) ⇒ Object



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# File 'lib/paperclip/storage/s3.rb', line 283

def set_storage_class(storage_class)
  storage_class = {:default => storage_class} unless storage_class.respond_to?(:merge)
  storage_class
end

#using_http_proxy?Boolean

Returns:

  • (Boolean)


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# File 'lib/paperclip/storage/s3.rb', line 258

def using_http_proxy?
  !!@http_proxy
end