add creationDate property to image resource

Change-Id: I23e3f758def10fb0f89e070e7b4fec75dba44f1f

README.rst

@@ -116,7 +116,6 @@ Availability zone related:
 
 Image related:
 - CopyImage
-- creationDate Image property
 - platform Image property
 - productCodes Image property
 - hypervisor Image property

ec2api/api/image.py

@@ -481,6 +481,7 @@ def _format_image(context, image, os_image, images_dict, ids_dict,
                                    ec2utils.get_ec2_id_kind(image['id'])],
                  'isPublic': image['is_public'],
                  'architecture': os_image.properties.get('architecture'),
+                 'creationDate': os_image.created_at
                  }
     if 'description' in image:
         ec2_image['description'] = image['description']

ec2api/tests/functional/api/test_images.py

@@ -214,6 +214,7 @@ class ImageTest(base.EC2TestCase):
         self.assertEqual(1, len(data['Images']))
         image = data['Images'][0]
 
+        self.assertIsNotNone(image['CreationDate'])
         self.assertEqual("ebs", image['RootDeviceType'])
         self.assertFalse(image['Public'])
         self.assertEqual(name, image['Name'])

ec2api/tests/unit/fakes.py

@@ -1079,6 +1079,7 @@ class OSImage(object):
     def __init__(self, image_dict):
         self.id = image_dict['id']
         self.owner = image_dict.get('owner')
+        self.created_at = image_dict.get('created_at')
         self.is_public = image_dict.get('is_public')
         self.status = image_dict.get('status')
         self.container_format = image_dict.get('container_format')
@@ -1098,9 +1099,12 @@ class OSImage(object):
     def delete(self):
         pass
 
+TIME_CREATE_IMAGE = timeutils.isotime(None, True)
+
 EC2_IMAGE_1 = {
     'imageId': ID_EC2_IMAGE_1,
     'imageOwnerId': ID_OS_PROJECT,
+    'creationDate': TIME_CREATE_IMAGE,
     'isPublic': False,
     'imageState': 'available',
     'imageType': 'machine',
@@ -1133,6 +1137,7 @@ EC2_IMAGE_1 = {
 EC2_IMAGE_2 = {
     'imageId': ID_EC2_IMAGE_2,
     'imageOwnerId': ID_OS_PROJECT,
+    'creationDate': TIME_CREATE_IMAGE,
     'isPublic': True,
     'imageState': 'available',
     'imageType': 'machine',
@@ -1174,6 +1179,7 @@ DB_IMAGE_ARI_1 = {
 OS_IMAGE_1 = {
     'id': ID_OS_IMAGE_1,
     'owner': ID_OS_PROJECT,
+    'created_at': TIME_CREATE_IMAGE,
     'is_public': False,
     'status': 'active',
     'container_format': 'ami',
@@ -1215,6 +1221,7 @@ OS_IMAGE_1 = {
 OS_IMAGE_2 = {
     'id': ID_OS_IMAGE_2,
     'owner': ID_OS_PROJECT,
+    'created_at': TIME_CREATE_IMAGE,
     'is_public': True,
     'status': 'active',
     'container_format': 'ami',