first pass at describe instances

lib/fog/aws/ec2.rb

@@ -210,6 +210,22 @@ module Fog
         }.merge!(params), Fog::Parsers::AWS::EC2::DescribeImages.new)
       end
       
+      # Describe all or specified instances
+      #
+      # ==== Parameters
+      # instance_id<~Array>:: List of instance ids to describe, defaults to all
+      #
+      # ==== Returns
+      # response::
+      #   body<~Hash>::
+      #     :request_id<~String>:: Id of request
+      def describe_instances(instance_id = [])
+        params = indexed_params('InstanceId', instance_id)
+        request({
+          'Action' => 'DescribeInstances',
+        }.merge!(params), Fog::Parsers::AWS::EC2::DescribeInstances.new)
+      end
+      
       # Describe all or specified key pairs
       #
       # ==== Parameters

lib/fog/aws/ec2/parsers.rb

@@ -139,6 +139,84 @@ module Fog
 
         end
 
+        class DescribeInstances < Fog::Parsers::Base
+
+          def reset
+            @instance = { :instance_state => {}, :placement => [], :product_code_set => [] }
+            @reservation = { :group_set => [], :instance_set => [] }
+            @response = { :reservation_set => [] }
+          end
+
+          def start_element(name, attrs = [])
+            if name == 'groupSet'
+              @in_subset = true
+            end
+            if name == 'productCodeSet'
+              @in_subset = true
+            end
+            if name == 'instanceSet'
+              @in_instance_set = true
+            end
+            @value = ''
+          end
+
+          def end_element
+            case name
+            when 'amiLaunchIndex'
+              @instance[:ami_launch_index] = @value
+            when 'availabilityZone'
+              @instance[:placement] << @value
+            when 'code'
+              @instance[:instance_state][:code] = @value
+            when 'dnsNmae'
+              @instance[:dns_name] = @value
+            when 'groupId'
+              @reservation[:group_set] << @value
+            when 'groupSet'
+              @in_subset = false
+            when 'imageId'
+              @instance[:image_id] = @value
+            when 'instanceId'
+              @instance[:instance_id] = @value
+            when 'instanceSet'
+              @in_instance_set = false
+            when 'instanceType'
+              @instance[:instance_type] = @value
+            when 'item'
+              if @in_instance_set
+                @reservation[:instance_set] << @instance
+                @instance = { :instance_state => {}, :placement => [], :product_code_set => [] }
+              elsif !@in_subset
+                @response[:reservation_set] << @reservation
+                @reservation = { :group_set => [], :instance_set => [] }
+              end
+            when 'kernelId'
+              @instance[:kernel_id] = @value
+            when 'keyName'
+              @instance[:key_name] = @value
+            when 'launchTime'
+              @instance[:launch_time] = Time.parse(@value)
+            when 'name'
+              @instance[:instance_state][:name] = @value
+            when 'ownerId'
+              @reservation[:owner_id] = @value
+            when 'requestId'
+              @response[:request_id] = @value
+            when 'reservationId'
+              @reservation[:reservation_id] = @value
+            when 'privateDnsName'
+              @instance[:private_dns_name] = @value
+            when 'productCode'
+              @instance[:product_code_set] << @value
+            when 'productCodeSet'
+              @in_subset = false
+            when 'ramdiskId'
+              @instance[:ramdisk_id] = @value
+            end
+          end
+
+        end
+
         class DescribeKeyPairs < Fog::Parsers::Base
 
           def reset

spec/aws/ec2/describe_instances_spec.rb

@@ -0,0 +1,12 @@
+require File.dirname(__FILE__) + '/../../spec_helper'
+
+describe 'EC2.instances' do
+
+  it "should return proper attributes with no params" do
+    actual = ec2.describe_instances
+    p actual
+  end
+  
+  it "should return proper attributes with params"
+
+end