feat(contrib/ec2): add support for internal ELBs

Author: Saso Matejina

contrib/ec2/deis.template.json

@@ -271,6 +271,7 @@
       "Type": "AWS::ElasticLoadBalancing::LoadBalancer",
       "DependsOn" : "GatewayToInternet",
       "Properties": {
+        "Scheme" : "internet-facing",
         "HealthCheck": {
           "HealthyThreshold": "4",
           "Interval": "15",

contrib/ec2/gen-json.py

@@ -90,6 +90,11 @@
 VPC_ID = os.getenv('VPC_ID', None)
 VPC_SUBNETS = os.getenv('VPC_SUBNETS', None)
 VPC_ZONES = os.getenv('VPC_ZONES', None)
+ELB_SCHEME = os.getenv('ELB_SCHEME', None)
+
+if ELB_SCHEME:
+  # Update ELB Scheme
+  template['Resources']['DeisWebELB']['Properties']['Scheme'] = ELB_SCHEME
 
 if VPC_ID and VPC_SUBNETS and VPC_ZONES and len(VPC_SUBNETS.split(',')) == len(VPC_ZONES.split(',')):
   # skip VPC, subnet, route, and internet gateway creation

docs/installing_deis/aws.rst

@@ -135,6 +135,15 @@ For example, if your VPC has ID ``vpc-a26218bf`` and consists of the subnets ``s
     export VPC_SUBNETS=subnet-04d7f942,subnet-2b03ab7f
     export VPC_ZONES=us-east-1b,us-east-1c
 
+Change ELB Scheme
+------------------------
+For load balancers attached to an Amazon VPC, this parameter can be used to specify the type of load balancer to use. 
+Specify internal to create an internal load balancer with a DNS name that resolves to private IP addresses or 
+internet-facing to create a load balancer with a publicly resolvable DNS name, which resolves to public IP addresses.
+
+.. code-block:: console
+
+    export ELB_SCHEME=internet-facing|internal
 
 Run the Provision Script
 ------------------------