From 316418df55950fbd2c141fcd4580a4dd3cb3e633 Mon Sep 17 00:00:00 2001
From: Steve Pulec <spulec@gmail.com>
Date: Tue, 5 Mar 2013 22:53:53 -0500
Subject: [PATCH] add subnets

---
 moto/ec2/models.py             | 32 +++++++++++++++++-
 moto/ec2/responses/subnets.py  | 61 +++++++++++++++++++++++++++++++---
 moto/ec2/utils.py              |  4 +++
 tests/test_ec2/test_subnets.py | 16 ++++++++-
 4 files changed, 107 insertions(+), 6 deletions(-)

diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index a921fc571..c254e1716 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -9,6 +9,7 @@ from .utils import (
     random_reservation_id,
     random_security_group_id,
     random_snapshot_id,
+    random_subnet_id,
     random_volume_id,
     random_vpc_id,
 )
@@ -408,6 +409,9 @@ class VPCBackend(object):
         self.vpcs[vpc_id] = vpc
         return vpc
 
+    def get_vpc(self, vpc_id):
+        return self.vpcs.get(vpc_id)
+
     def get_all_vpcs(self):
         return self.vpcs.values()
 
@@ -415,9 +419,35 @@ class VPCBackend(object):
         return self.vpcs.pop(vpc_id, None)
 
 
+class Subnet(object):
+    def __init__(self, subnet_id, vpc, cidr_block):
+        self.id = subnet_id
+        self.vpc = vpc
+        self.cidr_block = cidr_block
+
+
+class SubnetBackend(object):
+    def __init__(self):
+        self.subnets = {}
+        super(SubnetBackend, self).__init__()
+
+    def create_subnet(self, vpc_id, cidr_block):
+        subnet_id = random_subnet_id()
+        vpc = self.get_vpc(vpc_id)
+        subnet = Subnet(subnet_id, vpc, cidr_block)
+        self.subnets[subnet_id] = subnet
+        return subnet
+
+    def get_all_subnets(self):
+        return self.subnets.values()
+
+    def delete_subnet(self, subnet_id):
+        return self.subnets.pop(subnet_id, None)
+
+
 class EC2Backend(BaseBackend, InstanceBackend, TagBackend, AmiBackend,
                  RegionsAndZonesBackend, SecurityGroupBackend, EBSBackend,
-                 VPCBackend):
+                 VPCBackend, SubnetBackend):
     pass
 
 
diff --git a/moto/ec2/responses/subnets.py b/moto/ec2/responses/subnets.py
index 6cbe9c7f8..97a5da287 100644
--- a/moto/ec2/responses/subnets.py
+++ b/moto/ec2/responses/subnets.py
@@ -1,15 +1,68 @@
 from jinja2 import Template
 
 from moto.ec2.models import ec2_backend
-from moto.ec2.utils import resource_ids_from_querystring
 
 
 class Subnets(object):
+    def __init__(self, querystring):
+        self.querystring = querystring
+
     def create_subnet(self):
-        raise NotImplementedError('Subnets(AmazonVPC).create_subnet is not yet implemented')
+        vpc_id = self.querystring.get('VpcId')[0]
+        cidr_block = self.querystring.get('CidrBlock')[0]
+        subnet = ec2_backend.create_subnet(vpc_id, cidr_block)
+        template = Template(CREATE_SUBNET_RESPONSE)
+        return template.render(subnet=subnet)
 
     def delete_subnet(self):
-        raise NotImplementedError('Subnets(AmazonVPC).delete_subnet is not yet implemented')
+        subnet_id = self.querystring.get('SubnetId')[0]
+        subnet = ec2_backend.delete_subnet(subnet_id)
+        if subnet:
+            template = Template(DELETE_SUBNET_RESPONSE)
+            return template.render(subnet=subnet)
+        else:
+            return "", dict(status=404)
 
     def describe_subnets(self):
-        raise NotImplementedError('Subnets(AmazonVPC).describe_subnets is not yet implemented')
+        subnets = ec2_backend.get_all_subnets()
+        template = Template(DESCRIBE_SUBNETS_RESPONSE)
+        return template.render(subnets=subnets)
+
+
+CREATE_SUBNET_RESPONSE = """
+<CreateSubnetResponse xmlns="http://ec2.amazonaws.com/doc/2012-12-01/">
+  <requestId>7a62c49f-347e-4fc4-9331-6e8eEXAMPLE</requestId>
+  <subnet>
+    <subnetId>{{ subnet.id }}</subnetId>
+    <state>pending</state>
+    <vpcId>{{ subnet.vpc.id }}</vpcId>
+    <cidrBlock>{{ subnet.cidr_block }}</cidrBlock>
+    <availableIpAddressCount>251</availableIpAddressCount>
+    <availabilityZone>us-east-1a</availabilityZone>
+    <tagSet/>
+  </subnet>
+</CreateSubnetResponse>"""
+
+DELETE_SUBNET_RESPONSE = """
+<DeleteSubnetResponse xmlns="http://ec2.amazonaws.com/doc/2012-12-01/">
+   <requestId>7a62c49f-347e-4fc4-9331-6e8eEXAMPLE</requestId>
+   <return>true</return>
+</DeleteSubnetResponse>"""
+
+DESCRIBE_SUBNETS_RESPONSE = """
+<DescribeSubnetsResponse xmlns="http://ec2.amazonaws.com/doc/2012-12-01/">
+  <requestId>7a62c49f-347e-4fc4-9331-6e8eEXAMPLE</requestId>
+  <subnetSet>
+    {% for subnet in subnets %}
+      <item>
+        <subnetId>{{ subnet.id }}</subnetId>
+        <state>available</state>
+        <vpcId>{{ subnet.vpc.id }}</vpcId>
+        <cidrBlock>{{ subnet.cidr_block }}</cidrBlock>
+        <availableIpAddressCount>251</availableIpAddressCount>
+        <availabilityZone>us-east-1a</availabilityZone>
+        <tagSet/>
+      </item>
+    {% endfor %}
+  </subnetSet>
+</DescribeSubnetsResponse>"""
diff --git a/moto/ec2/utils.py b/moto/ec2/utils.py
index a12ac153b..258927f05 100644
--- a/moto/ec2/utils.py
+++ b/moto/ec2/utils.py
@@ -33,6 +33,10 @@ def random_vpc_id():
     return random_id(prefix='vpc')
 
 
+def random_subnet_id():
+    return random_id(prefix='subnet')
+
+
 def random_snapshot_id():
     return random_id(prefix='snap')
 
diff --git a/tests/test_ec2/test_subnets.py b/tests/test_ec2/test_subnets.py
index f73a8feda..e6ebebc6b 100644
--- a/tests/test_ec2/test_subnets.py
+++ b/tests/test_ec2/test_subnets.py
@@ -1,4 +1,5 @@
 import boto
+from boto.exception import EC2ResponseError
 import sure  # flake8: noqa
 
 from moto import mock_ec2
@@ -6,4 +7,17 @@ from moto import mock_ec2
 
 @mock_ec2
 def test_subnets():
-    pass
+    conn = boto.connect_vpc('the_key', 'the_secret')
+    vpc = conn.create_vpc("10.0.0.0/16")
+    subnet = conn.create_subnet(vpc.id, "10.0.0.0/18")
+
+    all_subnets = conn.get_all_subnets()
+    all_subnets.should.have.length_of(1)
+
+    conn.delete_subnet(subnet.id)
+
+    all_subnets = conn.get_all_subnets()
+    all_subnets.should.have.length_of(0)
+
+    conn.delete_subnet.when.called_with(
+        subnet.id).should.throw(EC2ResponseError)