From 4ba4dd5e2610da6419cbafc5f2b140ddd6ac4428 Mon Sep 17 00:00:00 2001
From: "Chris St. Pierre" <chris.a.st.pierre@gmail.com>
Date: Wed, 7 May 2014 08:47:25 -0400
Subject: [PATCH] Added subnet_id support to instances

---
 moto/ec2/models.py               |  2 ++
 moto/ec2/responses/instances.py  |  8 ++++++--
 tests/test_ec2/test_instances.py | 10 ++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index f1477245..91f16e4c 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -45,6 +45,7 @@ class Instance(BotoInstance):
         self.user_data = user_data
         self.security_groups = security_groups
         self.instance_type = kwargs.get("instance_type", "m1.small")
+        self.subnet_id = kwargs.get("subnet_id")
 
     @classmethod
     def create_from_cloudformation_json(cls, resource_name, cloudformation_json):
@@ -59,6 +60,7 @@ class Instance(BotoInstance):
             count=1,
             security_group_names=group_names,
             instance_type=properties.get("InstanceType", "m1.small"),
+            subnet_id=properties.get("SubnetId")
         )
         return reservation.instances[0]
 
diff --git a/moto/ec2/responses/instances.py b/moto/ec2/responses/instances.py
index 28047413..a153713c 100644
--- a/moto/ec2/responses/instances.py
+++ b/moto/ec2/responses/instances.py
@@ -34,7 +34,10 @@ class InstanceResponse(BaseResponse):
         user_data = self.querystring.get('UserData')
         security_group_names = self._get_multi_param('SecurityGroup')
         instance_type = self.querystring.get("InstanceType", ["m1.small"])[0]
-        new_reservation = ec2_backend.add_instances(image_id, min_count, user_data, security_group_names, instance_type=instance_type)
+        subnet_id = self.querystring.get("SubnetId", [None])[0]
+        new_reservation = ec2_backend.add_instances(
+            image_id, min_count, user_data, security_group_names,
+            instance_type=instance_type, subnet_id=subnet_id)
         template = Template(EC2_RUN_INSTANCES)
         return template.render(reservation=new_reservation)
 
@@ -122,6 +125,7 @@ EC2_RUN_INSTANCES = """<RunInstancesResponse xmlns="http://ec2.amazonaws.com/doc
           <monitoring>
             <state>enabled</state>
           </monitoring>
+          <subnetId>{{ instance.subnet_id }}</subnetId>
           <sourceDestCheck>true</sourceDestCheck>
           <groupSet>
              {% for group in instance.security_groups %}
@@ -174,7 +178,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns='http://ec2.amazona
                     <monitoring>
                       <state>disabled</state>
                     </monitoring>
-                    <subnetId>subnet-1a2b3c4d</subnetId>
+                    <subnetId>{{ instance.subnet_id }}</subnetId>
                     <vpcId>vpc-1a2b3c4d</vpcId>
                     <privateIpAddress>10.0.0.12</privateIpAddress>
                     <ipAddress>46.51.219.63</ipAddress>
diff --git a/tests/test_ec2/test_instances.py b/tests/test_ec2/test_instances.py
index 43315fd0..7d2b4457 100644
--- a/tests/test_ec2/test_instances.py
+++ b/tests/test_ec2/test_instances.py
@@ -191,3 +191,13 @@ def test_run_instance_with_instance_type():
     instance = reservation.instances[0]
 
     instance.instance_type.should.equal("t1.micro")
+
+
+@mock_ec2
+def test_run_instance_with_subnet():
+    conn = boto.connect_ec2('the_key', 'the_secret')
+    reservation = conn.run_instances('ami-1234abcd',
+                                     subnet_id="subnet-abcd1234")
+    instance = reservation.instances[0]
+
+    instance.subnet_id.should.equal("subnet-abcd1234")