From a63601e4819f2e4fcd7b0c79a426cfc15c442456 Mon Sep 17 00:00:00 2001
From: Ilya Sukhanov <ilya@sukhanov.net>
Date: Thu, 29 Aug 2013 23:06:11 -0400
Subject: [PATCH] Implement ImageId parameter in DescribeImages

---
 moto/ec2/models.py         | 8 ++++++--
 moto/ec2/responses/amis.py | 5 +++--
 moto/ec2/utils.py          | 8 ++++++++
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index ccde643e9..39b3c83ff 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -215,8 +215,12 @@ class AmiBackend(object):
         self.amis[ami_id] = ami
         return ami
 
-    def describe_images(self):
-        return self.amis.values()
+    def describe_images(self, ami_ids=None):
+        if ami_ids:
+            images = [image for image in self.amis.values() if image.id in ami_ids]
+        else:
+            images = self.amis.values()
+        return images
 
     def deregister_image(self, ami_id):
         if ami_id in self.amis:
diff --git a/moto/ec2/responses/amis.py b/moto/ec2/responses/amis.py
index b6e856388..10936e635 100644
--- a/moto/ec2/responses/amis.py
+++ b/moto/ec2/responses/amis.py
@@ -1,7 +1,7 @@
 from jinja2 import Template
 
 from moto.ec2.models import ec2_backend
-from moto.ec2.utils import instance_ids_from_querystring
+from moto.ec2.utils import instance_ids_from_querystring, image_ids_from_querystring
 
 
 class AmisResponse(object):
@@ -33,7 +33,8 @@ class AmisResponse(object):
         raise NotImplementedError('AMIs.describe_image_attribute is not yet implemented')
 
     def describe_images(self):
-        images = ec2_backend.describe_images()
+        ami_ids = image_ids_from_querystring(self.querystring)
+        images = ec2_backend.describe_images(ami_ids=ami_ids)
         template = Template(DESCRIBE_IMAGES_RESPONSE)
         return template.render(images=images)
 
diff --git a/moto/ec2/utils.py b/moto/ec2/utils.py
index 2710cc46d..5fcafb835 100644
--- a/moto/ec2/utils.py
+++ b/moto/ec2/utils.py
@@ -54,6 +54,14 @@ def instance_ids_from_querystring(querystring_dict):
     return instance_ids
 
 
+def image_ids_from_querystring(querystring_dict):
+    image_ids = []
+    for key, value in querystring_dict.iteritems():
+        if 'ImageId' in key:
+            image_ids.append(value[0])
+    return image_ids
+
+
 def resource_ids_from_querystring(querystring_dict):
     prefix = 'ResourceId'
     response_values = {}