Module: RightAws::RightAwsBaseInterface

Included in:
AcfInterface, AcwInterface, AsInterface, Ec2, ElbInterface, SdbInterface, SqsGen2Interface, SqsInterface
Defined in:
lib/awsbase/right_awsbase.rb

Constant Summary collapse

DEFAULT_SIGNATURE_VERSION = 
'2'
@@caching = 
false

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#aws_access_key_id ⇒ Object (readonly)

Current aws_access_key_id



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# File 'lib/awsbase/right_awsbase.rb', line 186

def aws_access_key_id
  @aws_access_key_id
end

#cache ⇒ Object (readonly)

Cache



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# File 'lib/awsbase/right_awsbase.rb', line 202

def cache
  @cache
end

#connection ⇒ Object (readonly)

RightHttpConnection instance



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# File 'lib/awsbase/right_awsbase.rb', line 200

def connection
  @connection
end

#last_errors ⇒ Object

Last AWS errors list (used by AWSErrorHandler)



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# File 'lib/awsbase/right_awsbase.rb', line 192

def last_errors
  @last_errors
end

#last_request ⇒ Object (readonly)

Last HTTP request object



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# File 'lib/awsbase/right_awsbase.rb', line 188

def last_request
  @last_request
end

#last_request_id ⇒ Object

Returns Amazons request ID for the latest request



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# File 'lib/awsbase/right_awsbase.rb', line 194

def last_request_id
  @last_request_id
end

#last_response ⇒ Object (readonly)

Last HTTP response object



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# File 'lib/awsbase/right_awsbase.rb', line 190

def last_response
  @last_response
end

#logger ⇒ Object

Logger object



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# File 'lib/awsbase/right_awsbase.rb', line 196

def logger
  @logger
end

#params ⇒ Object

Initial params hash



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# File 'lib/awsbase/right_awsbase.rb', line 198

def params
  @params
end

#signature_version ⇒ Object (readonly)

Signature version (all services except s3)



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# File 'lib/awsbase/right_awsbase.rb', line 204

def signature_version
  @signature_version
end

Class Method Details

.caching ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 178

def self.caching
  @@caching
end

.caching=(caching) ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 181

def self.caching=(caching)
  @@caching = caching
end

Instance Method Details

#amazonize_list(masks, list) ⇒ Object

Format array of items into Amazons handy hash (‘?’ is a place holder):

amazonize_list('Item', ['a', 'b', 'c']) =>
  { 'Item.1' => 'a', 'Item.2' => 'b', 'Item.3' => 'c' }

amazonize_list('Item.?.instance', ['a', 'c']) #=>
  { 'Item.1.instance' => 'a', 'Item.2.instance' => 'c' }

amazonize_list(['Item.?.Name', 'Item.?.Value'], {'A' => 'a', 'B' => 'b'}) #=>
  { 'Item.1.Name' => 'A', 'Item.1.Value' => 'a',
    'Item.2.Name' => 'B', 'Item.2.Value' => 'b'  }

amazonize_list(['Item.?.Name', 'Item.?.Value'], [['A','a'], ['B','b']]) #=>
  { 'Item.1.Name' => 'A', 'Item.1.Value' => 'a',
    'Item.2.Name' => 'B', 'Item.2.Value' => 'b'  }



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# File 'lib/awsbase/right_awsbase.rb', line 484

def amazonize_list(masks, list) #:nodoc:
  groups = {}
  list.to_a.each_with_index do |list_item, i|
    masks.to_a.each_with_index do |mask, mask_idx|
      key = mask[/\?/] ? mask.dup : mask.dup + '.?'
      key.gsub!('?', (i+1).to_s)
      groups[key] = list_item.to_a[mask_idx]
    end
  end
  groups
end

#cache_hits?(function, response, do_raise = :raise) ⇒ Boolean

Check if the aws function response hits the cache or not. If the cache hits:

  • raises an AwsNoChange exception if do_raise == :raise.

  • returnes parsed response from the cache if it exists or true otherwise.

If the cache miss or the caching is off then returns false.

Returns:

  • (Boolean) 


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# File 'lib/awsbase/right_awsbase.rb', line 264

def cache_hits?(function, response, do_raise=:raise)
  result = false
  if caching?
    function = function.to_sym
    # get rid of requestId (this bad boy was added for API 2008-08-08+ and it is uniq for every response)
    # feb 04, 2009 (load balancer uses 'RequestId' hence use 'i' modifier to hit it also)
    response = response.sub(%r{<requestId>.+?</requestId>}i, '')
    response_md5 = MD5.md5(response).to_s
    # check for changes
    unless @cache[function] && @cache[function][:response_md5] == response_md5
      # well, the response is new, reset cache data
      update_cache(function, {:response_md5 => response_md5, 
                              :timestamp    => Time.now, 
                              :hits         => 0, 
                              :parsed       => nil})
    else
      # aha, cache hits, update the data and throw an exception if needed
      @cache[function][:hits] += 1
      if do_raise == :raise
        raise(AwsNoChange, "Cache hit: #{function} response has not changed since "+
                           "#{@cache[function][:timestamp].strftime('%Y-%m-%d %H:%M:%S')}, "+
                           "hits: #{@cache[function][:hits]}.")
      else
        result = @cache[function][:parsed] || true
      end
    end
  end
  result
end

#caching? ⇒ Boolean

Returns true if the describe_xxx responses are being cached

Returns:

  • (Boolean) 


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# File 'lib/awsbase/right_awsbase.rb', line 255

def caching?
  @params.key?(:cache) ? @params[:cache] : @@caching
end

#generate_request_impl(verb, action, options = {}) ⇒ Object

ACF, AMS, EC2, LBS and SDB uses this guy SQS and S3 use their own methods



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# File 'lib/awsbase/right_awsbase.rb', line 310

def generate_request_impl(verb, action, options={}) #:nodoc:
  # Form a valid http verb: 'GET' or 'POST' (all the other are not supported now)
  http_verb = verb.to_s.upcase
  # remove empty keys from request options
  options.delete_if { |key, value| value.nil? }
  # prepare service data
  service_hash = {"Action"         => action,
                  "AWSAccessKeyId" => @aws_access_key_id,
                  "Version"        => @params[:api_version] }
  service_hash.merge!(options)
  # Sign request options
  service_params = signed_service_params(@aws_secret_access_key, service_hash, http_verb, @params[:server], @params[:service])
  # Use POST if the length of the query string is too large
  # see http://docs.amazonwebservices.com/AmazonSimpleDB/2007-11-07/DeveloperGuide/MakingRESTRequests.html
  if http_verb != 'POST' && service_params.size > 2000
    http_verb = 'POST'
    if signature_version == '2'
      service_params = signed_service_params(@aws_secret_access_key, service_hash, http_verb, @params[:server], @params[:service])
    end
  end
  # create a request
  case http_verb
  when 'GET'
    request = Net::HTTP::Get.new("#{@params[:service]}?#{service_params}")
  when 'POST'
    request      = Net::HTTP::Post.new(@params[:service])
    request.body = service_params
    request['Content-Type'] = 'application/x-www-form-urlencoded'
  else
    raise "Unsupported HTTP verb #{verb.inspect}!"
  end
  # prepare output hash
  { :request  => request,
    :server   => @params[:server],
    :port     => @params[:port],
    :protocol => @params[:protocol] }
end

#get_connection(aws_service, request) ⇒ Object

:nodoc



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# File 'lib/awsbase/right_awsbase.rb', line 348

def get_connection(aws_service, request) #:nodoc
  server_url = "#{request[:protocol]}://#{request[:server]}:#{request[:port]}}"
  #
  case @params[:connections].to_s
  when 'dedicated'
    @connections_storage ||= {}
  else # 'dedicated'
    @connections_storage = (Thread.current[aws_service] ||= {})
  end
  #
  @connections_storage[server_url] ||= {}
  @connections_storage[server_url][:last_used_at] = Time.now
  @connections_storage[server_url][:connection] ||= Rightscale::HttpConnection.new(:exception => RightAws::AwsError, :logger => @logger)
  # keep X most recent connections (but were used not far than Y minutes ago)
  connections = 0
  @connections_storage.to_a.sort{|i1, i2| i2[1][:last_used_at] <=> i1[1][:last_used_at]}.to_a.each do |i|
    if i[0] != server_url && (@params[:max_connections] <= connections  || i[1][:last_used_at] < Time.now - @params[:connection_lifetime])
      # delete the connection from the list
      @connections_storage.delete(i[0])
      # then finish it
      i[1][:connection].finish((@params[:max_connections] <= connections) ? "out-of-limit" : "out-of-date") rescue nil
    else
      connections += 1
    end
  end
  @connections_storage[server_url][:connection]
end

#init(service_info, aws_access_key_id, aws_secret_access_key, params = {}) ⇒ Object

:nodoc:

Raises:



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# File 'lib/awsbase/right_awsbase.rb', line 206

def init(service_info, aws_access_key_id, aws_secret_access_key, params={}) #:nodoc:
  @params = params
  # If one defines EC2_URL he may forget to use a single slash as an "empty service" path.
  # Amazon does not like this therefore add this bad boy if he is missing...
  service_info[:default_service] = '/' if service_info[:default_service].blank?
  raise AwsError.new("AWS access keys are required to operate on #{service_info[:name]}") \
    if aws_access_key_id.blank? || aws_secret_access_key.blank?
  @aws_access_key_id     = aws_access_key_id
  @aws_secret_access_key = aws_secret_access_key
  # if the endpoint was explicitly defined - then use it
  if @params[:endpoint_url]
    @params[:server]   = URI.parse(@params[:endpoint_url]).host
    @params[:port]     = URI.parse(@params[:endpoint_url]).port
    @params[:service]  = URI.parse(@params[:endpoint_url]).path
    # make sure the 'service' path is not empty
    @params[:service]  = service_info[:default_service] if @params[:service].blank?
    @params[:protocol] = URI.parse(@params[:endpoint_url]).scheme
    @params[:region]   = nil
  else
    @params[:server]   ||= service_info[:default_host]
    @params[:server]     = "#{@params[:region]}.#{@params[:server]}" if @params[:region]
    @params[:port]     ||= service_info[:default_port]
    @params[:service]  ||= service_info[:default_service]
    @params[:protocol] ||= service_info[:default_protocol]
  end
#      @params[:multi_thread] ||= defined?(AWS_DAEMON)
  @params[:connections] ||= :shared # || :dedicated
  @params[:max_connections] ||= 10
  @params[:connection_lifetime] ||= 20*60
  @params[:api_version]  ||= service_info[:default_api_version]
  @logger = @params[:logger]
  @logger = RAILS_DEFAULT_LOGGER if !@logger && defined?(RAILS_DEFAULT_LOGGER)
  @logger = Logger.new(STDOUT)   if !@logger
  @logger.info "New #{self.class.name} using #{@params[:connections]} connections mode"
  @error_handler = nil
  @cache = {}
  @signature_version = (params[:signature_version] || DEFAULT_SIGNATURE_VERSION).to_s
end

#on_exception(options = {:raise=>true, :log=>true}) ⇒ Object

:nodoc:



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# File 'lib/awsbase/right_awsbase.rb', line 298

def on_exception(options={:raise=>true, :log=>true}) # :nodoc:
  raise if $!.is_a?(AwsNoChange)
  AwsError::on_aws_exception(self, options)
end

#request_cache_or_info(method, link, parser_class, benchblock, use_cache = true) ⇒ Object

:nodoc:



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# File 'lib/awsbase/right_awsbase.rb', line 447

def request_cache_or_info(method, link, parser_class, benchblock, use_cache=true) #:nodoc:
  # We do not want to break the logic of parsing hence will use a dummy parser to process all the standard
  # steps (errors checking etc). The dummy parser does nothig - just returns back the params it received.
  # If the caching is enabled and hit then throw  AwsNoChange.
  # P.S. caching works for the whole images list only! (when the list param is blank)
  # check cache
  response, params = request_info(link, RightDummyParser.new)
  cache_hits?(method.to_sym, response.body) if use_cache
  parser = parser_class.new(:logger => @logger)
  benchblock.xml.add!{ parser.parse(response, params) }
  result = block_given? ? yield(parser) : parser.result
  # update parsed data
  update_cache(method.to_sym, :parsed => result) if use_cache
  result
end

#request_info_impl(aws_service, benchblock, request, parser, &block) ⇒ Object

All services uses this guy.



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# File 'lib/awsbase/right_awsbase.rb', line 377

def request_info_impl(aws_service, benchblock, request, parser, &block) #:nodoc:
  @connection    = get_connection(aws_service, request)
  @last_request  = request[:request]
  @last_response = nil
  response = nil
  blockexception = nil

  if(block != nil)
    # TRB 9/17/07 Careful - because we are passing in blocks, we get a situation where
    # an exception may get thrown in the block body (which is high-level
    # code either here or in the application) but gets caught in the
    # low-level code of HttpConnection.  The solution is not to let any
    # exception escape the block that we pass to HttpConnection::request.
    # Exceptions can originate from code directly in the block, or from user
    # code called in the other block which is passed to response.read_body.
    benchblock.service.add! do
      responsehdr = @connection.request(request) do |response|
      #########
        begin
          @last_response = response
          if response.is_a?(Net::HTTPSuccess)
            @error_handler = nil
            response.read_body(&block)
          else
            @error_handler = AWSErrorHandler.new(self, parser, :errors_list => self.class.amazon_problems) unless @error_handler
            check_result   = @error_handler.check(request)
            if check_result
              @error_handler = nil
              return check_result 
            end
            raise AwsError.new(@last_errors, @last_response.code, @last_request_id)
          end
        rescue Exception => e
          blockexception = e
        end
      end
      #########

      #OK, now we are out of the block passed to the lower level
      if(blockexception)
        raise blockexception
      end
      benchblock.xml.add! do
        parser.parse(responsehdr)
      end
      return parser.result
    end
  else
    benchblock.service.add!{ response = @connection.request(request) }
      # check response for errors...
    @last_response = response
    if response.is_a?(Net::HTTPSuccess)
      @error_handler = nil
      benchblock.xml.add! { parser.parse(response) }
      return parser.result
    else
      @error_handler = AWSErrorHandler.new(self, parser, :errors_list => self.class.amazon_problems) unless @error_handler
      check_result   = @error_handler.check(request)
      if check_result
        @error_handler = nil
        return check_result 
      end
      raise AwsError.new(@last_errors, @last_response.code, @last_request_id)
    end
  end
rescue
  @error_handler = nil
  raise
end

#signed_service_params(aws_secret_access_key, service_hash, http_verb = nil, host = nil, service = nil) ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 245

def signed_service_params(aws_secret_access_key, service_hash, http_verb=nil, host=nil, service=nil )
  case signature_version.to_s
  when '0' then AwsUtils::sign_request_v0(aws_secret_access_key, service_hash)
  when '1' then AwsUtils::sign_request_v1(aws_secret_access_key, service_hash)
  when '2' then AwsUtils::sign_request_v2(aws_secret_access_key, service_hash, http_verb, host, service)
  else raise AwsError.new("Unknown signature version (#{signature_version.to_s}) requested")
  end
end

#update_cache(function, hash) ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 294

def update_cache(function, hash)
  (@cache[function.to_sym] ||= {}).merge!(hash) if caching?
end