feat(contrib/ec2): launch into vpc

Modifies the cloudformation configuration to create resources within the
confines of a VPC.

fixes #1005

Author: rgarcia

contrib/ec2/README.md

@@ -60,6 +60,15 @@ by adding a new entry to [cloudformation.json](cloudformation.json) like so:
 The only entry in cloudformation.json required to launch your cluster is `KeyPair`,
 which is already filled out. The defaults will be applied for the other settings.
 
+## Choose whether to launch in VPC
+
+To launch you cluster into a VPC, export two additional environment variables:
+
+```
+export VPC_ID=vpc-a26218bf
+export VPC_SUBNETS=subnet-04d7f942,subnet-2b03ab7f
+```
+
 ## Run the provision script
 Run the [cloudformation provision script][pro-script] to spawn a new CoreOS cluster:
 ```console

contrib/ec2/gen-json.py

@@ -10,4 +10,21 @@
 template['Resources']['CoreOSServerLaunchConfig']['Properties']['UserData']['Fn::Base64']['Fn::Join'] = [ '', lines ]
 template['Parameters']['ClusterSize']['Default'] = str(os.getenv('DEIS_NUM_INSTANCES', 3))
 
+if os.getenv("VPC_ID", None) and os.getenv("VPC_SUBNETS", None):
+  for resource in template['Resources'].keys():
+    resource_type = template['Resources'][resource]['Type']
+    if resource_type == 'AWS::EC2::SecurityGroup':
+      template['Resources'][resource]['Properties']['VpcId'] = os.getenv("VPC_ID")
+    elif resource_type == 'AWS::EC2::SecurityGroupIngress':
+      template['Resources'][resource]['Properties']['GroupId'] = template['Resources'][resource]['Properties']['GroupName']
+      del template['Resources'][resource]['Properties']['GroupName']
+      template['Resources'][resource]['Properties']['SourceSecurityGroupId'] = {
+        'Ref': template['Resources'][resource]['Properties']['SourceSecurityGroupId']['Fn::GetAtt'][0]
+      }
+    elif resource_type == 'AWS::AutoScaling::LaunchConfiguration':
+      template['Resources'][resource]['Properties']['AssociatePublicIpAddress'] = False
+    elif resource_type == 'AWS::AutoScaling::AutoScalingGroup':
+      template['Resources'][resource]['Properties']['VPCZoneIdentifier'] = os.getenv('VPC_SUBNETS').split(',')
+
+
 print json.dumps(template)