modify db snapshot attribute api implementation

lib/fog/aws/parsers/rds/modify_db_snapshot_attribute.rb

@@ -0,0 +1,24 @@
+module Fog
+  module Parsers
+    module AWS
+      module RDS
+        class ModifyDbSnapshotAttribute < Fog::Parsers::Base
+          def reset
+            @response = { 'ModifyDbSnapshotAttributeResult' => {}, 'ResponseMetadata' => {} }
+          end
+
+          def start_element(name, attrs = [])
+            super
+          end
+
+          def end_element(name)
+            case name
+            when 'RequestId'
+              @response['ResponseMetadata'][name] = value
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/fog/aws/rds.rb

@@ -29,6 +29,7 @@ module Fog
       request :describe_db_snapshots
       request :create_db_snapshot
       request :delete_db_snapshot
+      request :modify_db_snapshot_attribute
 
       request :create_db_parameter_group
       request :delete_db_parameter_group

lib/fog/aws/requests/rds/modify_db_snapshot_attribute.rb

@@ -0,0 +1,32 @@
+module Fog
+  module AWS
+    class RDS
+      class Real
+        require 'fog/aws/parsers/rds/modify_db_snapshot_attribute'
+
+        # Modify db snapshot attributes
+        #
+        # ==== Parameters
+        # * db_snapshot_identifier<~String> - Id of snapshot to modify
+        # * attributes<~Hash>:
+        #   * 'Add.MemberId'<~Array> - One or more account ids to grant rds create permission to
+        #   * 'Remove.MemberId'<~Array> - One or more account ids to revoke rds create permission from
+        #
+        # {Amazon API Reference}[http://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBSnapshotAttribute.html]
+        #
+        def modify_db_snapshot_attribute(db_snapshot_identifier, attributes)
+          params = {}
+          params.merge!(Fog::AWS.indexed_param('ValuesToAdd.member.%d', attributes['Add.MemberId'] || []))
+          params.merge!(Fog::AWS.indexed_param('ValuesToRemove.member.%d', attributes['Remove.MemberId'] || []))
+          request({
+            'Action'        => 'ModifyDBSnapshotAttribute',
+            'DBSnapshotIdentifier'    => db_snapshot_identifier,
+            :idempotent     => true,
+            'AttributeName' => "restore",
+            :parser         => Fog::Parsers::AWS::RDS::ModifyDbSnapshotAttribute.new
+          }.merge!(params))
+        end
+      end
+    end
+  end
+end