Module: Aws::AwsBaseInterface

Included in:
AcfInterface, Ec2, Elb, Iam, Mon, Rds, S3Interface, SdbInterface, SqsInterface
Defined in:
lib/awsbase/awsbase.rb

Defined Under Namespace

Modules: ClassMethods

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/awsbase.rb', line 118

def aws_access_key_id
  @aws_access_key_id
end

#cache ⇒ Object (readonly)

RightHttpConnection instance there’s a method now to get this since it could be per thread or what have you attr_reader :connection Cache



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# File 'lib/awsbase/awsbase.rb', line 135

def cache
  @cache
end

#last_errors ⇒ Object

Last AWS errors list (used by AWSErrorHandler)



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# File 'lib/awsbase/awsbase.rb', line 124

def last_errors
  @last_errors
end

#last_request ⇒ Object (readonly)

Last HTTP request object



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# File 'lib/awsbase/awsbase.rb', line 120

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/awsbase.rb', line 126

def last_request_id
  @last_request_id
end

#last_response ⇒ Object (readonly)

Last HTTP response object



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# File 'lib/awsbase/awsbase.rb', line 122

def last_response
  @last_response
end

#logger ⇒ Object

Logger object



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# File 'lib/awsbase/awsbase.rb', line 128

def logger
  @logger
end

#params ⇒ Object

Initial params hash



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# File 'lib/awsbase/awsbase.rb', line 130

def params
  @params
end

#signature_version ⇒ Object (readonly)

Signature version (all services except s3)



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# File 'lib/awsbase/awsbase.rb', line 137

def signature_version
  @signature_version
end

Class Method Details

.caching ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 109

def self.caching
  @@caching
end

.caching=(caching) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 113

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

Instance Method Details

#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/awsbase.rb', line 430

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)
    response     = response.sub(%r{<requestId>.+?</requestId>}, '')
    response_md5 =Digest::MD5.hexdigest(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/awsbase.rb', line 421

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

#close_conn(conn_name) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 262

def close_conn(conn_name)
  conn_mode = @params[:connection_mode]
  if conn_mode == :per_thread || conn_mode == :single
    thread = conn_mode == :per_thread ? Thread.current : Thread.main
    if !thread[conn_name].nil?
      thread[conn_name].finish
      thread[conn_name] = nil
    end
  end
end

#close_connection ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 277

def close_connection
  close_conn(self.class.connection_name)
end

#connection ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 273

def connection
  get_conn(self.class.connection_name, self.params, self.logger)
end

#generate_request(action, params = {}) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 189

def generate_request(action, params={})
  generate_request2(@aws_access_key_id, @aws_secret_access_key, action, @params[:api_version], @params, params)
end

#generate_request2(aws_access_key, aws_secret_key, action, api_version, lib_params, user_params = {}, options = {}) ⇒ Object

FROM SDB



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

def generate_request2(aws_access_key, aws_secret_key, action, api_version, lib_params, user_params={}, options={}) #:nodoc:
  # remove empty params from request
  user_params.delete_if { |key, value| value.nil? }
#            user_params.each_pair do |k,v|
#                user_params[k] = v.force_encoding("UTF-8")
#            end
  #params_string  = params.to_a.collect{|key,val| key + "=#{CGI::escape(val.to_s)}" }.join("&")
  # prepare service data
  service      = lib_params[:service]
#      puts 'service=' + service.to_s
  service_hash = {"Action"         => action,
                  "AWSAccessKeyId" => aws_access_key}
  service_hash.update("Version" => api_version) if api_version
  service_hash.update(user_params)
  service_params = signed_service_params(aws_secret_key, service_hash, :get, lib_params[:server], lib_params[:service])
  #
  # use POST method if the length of the query string is too large
  # see http://docs.amazonwebservices.com/AmazonSimpleDB/2007-11-07/DeveloperGuide/MakingRESTRequests.html
  if service_params.size > 2000
    if signature_version == '2'
      # resign the request because HTTP verb is included into signature
      service_params = signed_service_params(aws_secret_key, service_hash, :post, lib_params[:server], service)
    end
    request                 = Net::HTTP::Post.new(service)
    request.body            = service_params
    request['Content-Type'] = 'application/x-www-form-urlencoded; charset=utf-8'
  else
    request = Net::HTTP::Get.new("#{service}?#{service_params}")
  end

  #puts "\n\n --------------- QUERY REQUEST TO AWS -------------- \n\n"
  #puts "#{@params[:service]}?#{service_params}\n\n"

  # prepare output hash
  {:request  => request,
   :server   => lib_params[:server],
   :port     => lib_params[:port],
   :protocol => lib_params[:protocol]}
end

#get_conn(connection_name, lib_params, logger) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 234

def get_conn(connection_name, lib_params, logger)
#            thread = lib_params[:multi_thread] ? Thread.current : Thread.main
#            thread[connection_name] ||= Rightscale::HttpConnection.new(:exception => Aws::AwsError, :logger => logger)
#            conn = thread[connection_name]
#            return conn
  http_conn = nil
  conn_mode = lib_params[:connection_mode]

  # Slice all parameters accepted by Rightscale::HttpConnection#new
  params    = lib_params.slice(
      :user_agent, :ca_file, :http_connection_retry_count, :http_connection_open_timeout,
      :http_connection_read_timeout, :http_connection_retry_delay
  )
  params.merge!(:exception => AwsError, :logger => logger)

  if conn_mode == :per_request
    http_conn = Rightscale::HttpConnection.new(params)

  elsif conn_mode == :per_thread || conn_mode == :single
    thread                  = conn_mode == :per_thread ? Thread.current : Thread.main
    thread[connection_name] ||= Rightscale::HttpConnection.new(params)
    http_conn               = thread[connection_name]
#                ret = request_info_impl(http_conn, bench, request, parser, &block)
  end
  return http_conn

end

#hash_params(prefix, list) ⇒ Object

:nodoc:



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# File 'lib/awsbase/awsbase.rb', line 569

def hash_params(prefix, list) #:nodoc:
  groups = {}
  list.each_index { |i| groups.update("#{prefix}.#{i+1}"=>list[i]) } if list
  return groups
end

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

:nodoc:

Raises:



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# File 'lib/awsbase/awsbase.rb', line 139

def init(service_info, aws_access_key_id, aws_secret_access_key, params={}) #:nodoc:
  @params = params
  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
    @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]
    @params[:api_version] ||= service_info[:api_version]
  end
  if !@params[:multi_thread].nil? && @params[:connection_mode].nil? # user defined this
    @params[:connection_mode] = @params[:multi_thread] ? :per_thread : :single
  end
#      @params[:multi_thread] ||= defined?(AWS_DAEMON)
  @params[:connection_mode] ||= :default
  @params[:connection_mode] = :per_request if @params[:connection_mode] == :default
  @logger = @params[:logger]
  @logger = Rails.logger if !@logger && defined?(Rails) && defined?(Rails.logger)
  @logger = ::Rails.logger if !@logger && defined?(::Rails.logger)
  @logger = Logger.new(STDOUT) if !@logger
  @logger.info "New #{self.class.name} using #{@params[:connection_mode].to_s}-connection mode"
  @error_handler     = nil
  @cache             = {}
  @signature_version = (params[:signature_version] || DEFAULT_SIGNATURE_VERSION).to_s
end

#multi_thread ⇒ Object

Return true if this instance works in multi_thread mode and false otherwise.



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# File 'lib/awsbase/awsbase.rb', line 469

def multi_thread
  @params[:multi_thread]
end

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

:nodoc:



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# File 'lib/awsbase/awsbase.rb', line 463

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/awsbase.rb', line 548

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_info2(request, parser, lib_params, connection_name, logger, bench, options = {}, &block) ⇒ Object

:nodoc:



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# File 'lib/awsbase/awsbase.rb', line 282

def request_info2(request, parser, lib_params, connection_name, logger, bench, options={}, &block) #:nodoc:
  ret       = nil
#            puts 'OPTIONS=' + options.inspect
  http_conn = get_conn(connection_name, lib_params, logger)
  begin
    # todo: this QueryTimeout retry should go into a SimpleDbErrorHandler, not here
    retry_count = 1
    count       = 0
    while count <= retry_count
      puts 'RETRYING QUERY due to QueryTimeout...' if count > 0
      begin
        ret = request_info_impl(http_conn, bench, request, parser, options, &block)
        break
      rescue Aws::AwsError => ex
        if !ex.include?(/QueryTimeout/) || count == retry_count
          raise ex
        end
      end
      count += 1
    end
  ensure
    http_conn.finish if http_conn && lib_params[:connection_mode] == :per_request
  end
  ret
end

#request_info3(service_interface, request, parser, options, &block) ⇒ Object

This is the latest and greatest now. Service must have connection_name defined.



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# File 'lib/awsbase/awsbase.rb', line 309

def request_info3(service_interface, request, parser, options, &block)
  request_info2(request, parser,
                service_interface.params,
                service_interface.class.connection_name,
                service_interface.logger,
                service_interface.class.bench,
                options, &block)
end

#request_info_impl(connection, benchblock, request, parser, options = {}, &block) ⇒ Object

:nodoc:



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# File 'lib/awsbase/awsbase.rb', line 474

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

#             puts 'OPTIONS2=' + options.inspect

  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, options)
            if check_result
              @error_handler = nil
              return check_result
            end
            request_text_data = "#{request[:server]}:#{request[:port]}#{request[:request].path}"
            raise AwsError.new(@last_errors, @last_response.code, @last_request_id, request_text_data)
          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, options)
      if check_result
        @error_handler = nil
        return check_result
      end
      request_text_data = "#{request[:server]}:#{request[:port]}#{request[:request].path}"
      raise AwsError.new(@last_errors, @last_response.code, @last_request_id, request_text_data)
    end
  end
rescue
  @error_handler = nil
  raise
end

#request_info_xml_simple(connection_name, lib_params, request, logger, params = {}) ⇒ Object

This is the direction we should head instead of writing our own parsers for everything, much simpler params:

- :group_tags => hash of indirection to eliminate, see: http://xml-simple.rubyforge.org/
- :force_array => true for all or an array of tag names to force
- :pull_out_array => an array of levels to dig into when generating return value (see rds.rb for example)



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# File 'lib/awsbase/awsbase.rb', line 324

def request_info_xml_simple(connection_name, lib_params, request, logger, params = {})

  connection = get_conn(connection_name, lib_params, logger)
  begin
    @last_request  = request[:request]
    @last_response = nil

    response       = connection.request(request)
    #       puts "response=" + response.body
#            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
      force_array        = params[:force_array] || false
      # Force_array and group_tags don't work nice together so going to force array manually
      xml_simple_options = {"KeyToSymbol"=>false, 'ForceArray' => false}
      xml_simple_options["GroupTags"] = params[:group_tags] if params[:group_tags]

#                { 'GroupTags' => { 'searchpath' => 'dir' }
#                'ForceArray' => %r(_list$)
      parsed = XmlSimple.xml_in(response.body, xml_simple_options)
      # todo: we may want to consider stripping off a couple of layers when doing this, for instance:
      # <DescribeDBInstancesResponse xmlns="http://rds.amazonaws.com/admin/2009-10-16/">
      #  <DescribeDBInstancesResult>
      #    <DBInstances>
      # <DBInstance>....
      # Strip it off and only return an array or hash of <DBInstance>'s (hash by identifier).
      # would have to be able to make the RequestId available somehow though, perhaps some special array subclass which included that?
      unless force_array.is_a? Array
        force_array = []
      end
      parsed = symbolize(parsed, force_array)
#                puts 'parsed=' + parsed.inspect
      if params[:pull_out_array]
        ret        = Aws::AwsResponseArray.new(parsed[:response_metadata])
        level_hash = parsed
        params[:pull_out_array].each do |x|
          level_hash = level_hash[x]
        end
        if level_hash.is_a? Hash # When there's only one
          ret << level_hash
        else # should be array
#                            puts 'level_hash=' + level_hash.inspect
          level_hash.each do |x|
            ret << x
          end
        end
      elsif params[:pull_out_single]
        # returns a single object
        ret        = AwsResponseObjectHash.new(parsed[:response_metadata])
        level_hash = parsed
        params[:pull_out_single].each do |x|
          level_hash = level_hash[x]
        end
        ret.merge!(level_hash)
      else
        ret = parsed
      end
      return ret

    else
      @error_handler = AWSErrorHandler.new(self, nil, :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
      request_text_data = "#{request[:server]}:#{request[:port]}#{request[:request].path}"
      raise AwsError2.new(@last_response.code, @last_request_id, request_text_data, @last_response.body)
    end
  ensure
    connection.finish if connection && lib_params[:connection_mode] == :per_request
  end

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/awsbase.rb', line 176

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

#symbolize(hash, force_array) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 403

def symbolize(hash, force_array)
  ret = {}
  hash.keys.each do |key|
    val = hash[key]
    if val.is_a? Hash
      val = symbolize(val, force_array)
      if force_array.include? key
        val = [val]
      end
    elsif val.is_a? Array
      val = val.collect { |x| symbolize(x, force_array) }
    end
    ret[key.underscore.to_sym] = val
  end
  ret
end

#update_cache(function, hash) ⇒ Object 



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# File 'lib/awsbase/awsbase.rb', line 459

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