From 7de0ef0f8b24f05580268324650b2d3cac600860 Mon Sep 17 00:00:00 2001
From: acsbendi <acsbendi28@gmail.com>
Date: Fri, 5 Jul 2019 15:24:16 +0200
Subject: [PATCH] Fixed value is present in response even if it's None.

---
 moto/ec2/responses/instances.py  | 2 ++
 tests/test_ec2/test_instances.py | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/moto/ec2/responses/instances.py b/moto/ec2/responses/instances.py
index 996324ef6..3bc8a44ac 100644
--- a/moto/ec2/responses/instances.py
+++ b/moto/ec2/responses/instances.py
@@ -597,7 +597,9 @@ EC2_DESCRIBE_INSTANCE_ATTRIBUTE = """<DescribeInstanceAttributeResponse xmlns="h
   <requestId>59dbff89-35bd-4eac-99ed-be587EXAMPLE</requestId>
   <instanceId>{{ instance.id }}</instanceId>
   <{{ attribute }}>
+    {% if value is not none %} 
     <value>{{ value }}</value>
+    {% endif %}
   </{{ attribute }}>
 </DescribeInstanceAttributeResponse>"""
 
diff --git a/tests/test_ec2/test_instances.py b/tests/test_ec2/test_instances.py
index 85dad28ae..a83384709 100644
--- a/tests/test_ec2/test_instances.py
+++ b/tests/test_ec2/test_instances.py
@@ -1290,8 +1290,12 @@ def test_describe_instance_attribute():
     for valid_instance_attribute in valid_instance_attributes:
         response = client.describe_instance_attribute(InstanceId=instance_id, Attribute=valid_instance_attribute)
         if valid_instance_attribute == "groupSet":
+            response.should.have.key("Groups")
             response["Groups"].should.have.length_of(1)
             response["Groups"][0]["GroupId"].should.equal(security_group_id)
+        elif valid_instance_attribute == "userData":
+            response.should.have.key("UserData")
+            response["UserData"].should.be.empty
 
     invalid_instance_attributes = ['abc', 'Kernel', 'RamDisk', 'userdata', 'iNsTaNcEtYpE']