Module: Aws::AwsBaseInterface

Included in:
AcfInterface, Ec2, Elb, Mon, Rds, S3Interface, SdbInterface, 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 298

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 314

def cache
  @cache
end

#connection ⇒ Object (readonly)

RightHttpConnection instance



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# File 'lib/awsbase/right_awsbase.rb', line 312

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 304

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 300

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 306

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 302

def last_response
  @last_response
end

#logger ⇒ Object

Logger object



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# File 'lib/awsbase/right_awsbase.rb', line 308

def logger
  @logger
end

#params ⇒ Object

Initial params hash



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

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 316

def signature_version
  @signature_version
end

Class Method Details

.caching ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 289

def self.caching
    @@caching
end

.caching=(caching) ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 293

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/right_awsbase.rb', line 524

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/right_awsbase.rb', line 515

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

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

FROM SDB



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# File 'lib/awsbase/right_awsbase.rb', line 367

def generate_request2(aws_access_key, aws_secret_key, action, api_version, lib_params, user_params={}) #: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'
    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/right_awsbase.rb', line 407

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
end

#hash_params(prefix, list) ⇒ Object

:nodoc:



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# File 'lib/awsbase/right_awsbase.rb', line 660

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/right_awsbase.rb', line 318

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]
    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_DEFAULT_LOGGER if !@logger && defined?(RAILS_DEFAULT_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/right_awsbase.rb', line 563

def multi_thread
    @params[:multi_thread]
end

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

:nodoc:



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# File 'lib/awsbase/right_awsbase.rb', line 557

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 639

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) ⇒ Object 



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# File 'lib/awsbase/right_awsbase.rb', line 414

def request_info2(request, parser, lib_params, connection_name, logger, bench)
    t = get_conn(connection_name, lib_params, logger)
    request_info_impl(t, bench, request, parser)
end

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

:nodoc:



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# File 'lib/awsbase/right_awsbase.rb', line 567

def request_info_impl(connection, benchblock, request, parser, &block) #:nodoc:
    @connection = connection
    @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
                        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)
            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/right_awsbase.rb', line 424

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

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

    response = @connection.request(request)
#            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
                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

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 353

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/right_awsbase.rb', line 497

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/right_awsbase.rb', line 553

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