在CloudFormation中的多个LoadBalancers之后添加实例？

Question

I am trying to figure out a way to add a ec2 node to two load balancers, but am not finding a sane way to do it. I would think that the below code would allow me to do this, but am not getting my expected results

Please note that this code is HIGHLY stripped down to just show the LB portion.

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": " App Demo / Jd / 01042016",
  "Parameters": {
    "LoadBalancers": {
      "Description": "Please refer the LoadBalancerNames which you want the instances to be registered to",
      "Type": "List<AWS::EC2::LoadBalancers::LoadBalancerNames>",
      "Default": "web-app-demo-ext,web-api-demo-ext"
    }
  },
  "Resources": {
    "AppAutoScalingGroup": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": {
          "Ref": "AZs"
        },
        "LoadBalancerNames": [{
          "Ref": "LoadBalancers"
        }]
      }
    }
  }
}

I would expect to see a list which I can add multiple LBs to, but I am instead seeing a normal input box (string)

Adding in images with some firebug hackery....

Expected Results

What actually happens

UPDATE

After fudging with Cloud Designer, I believe that "Type": "List<AWS::EC2::LoadBalancers::LoadBalancerNames>" is incorrect and should really be "Type": "List<AWS::ElasticLoadBalancing::LoadBalancer>"

This still does not propagate as a list though

Answer 1

Figured it out. You will need multiple references. And the reason is because the "LoadBalancerNames" key can take multiple references, like so: "LoadBalancerNames": { "Foo", "Bar" }

Really hope this helps someone else as it had me scratching my head for days :)

{
  ................
  "Parameters": {
    .......
    "LoadBalancerApp": {
      "Description": "Please refer the LoadBalancerNames (APP) which you want the instances to be registered to",
      "Type": "String",
      "Default": "web-app-demo-ext"
    },
    "LoadBalancerApi": {
      "Description": "Please refer the LoadBalancerNames (API) which you want the instances to be registered to",
      "Type": "String",
      "Default": "web-api-demo-ext"
    },
    .......
  },
  "Resources": {
    ........
    "AppnameAutoScalingGroup": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": {
          "Ref": "AZs"
        },
        "LaunchConfigurationName": {
          "Ref": "AppnameLaunchConfig"
        },
        "LoadBalancerNames": [{
          "Ref": "LoadBalancerApp"
        }, {
          "Ref": "LoadBalancerApi"
        }],
    ..........
}

Answer 2

This won't give you the UI you were looking for, but it will allow you to specify multiple load balancer names in a single parameter.

Use CommaDelimitedList as the parameter type.

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": " App Demo / Jd / 01042016",
  "Parameters": {
    "LoadBalancers": {
      "Description": "Please refer the LoadBalancerNames which you want the instances to be registered to",
      "Type": "CommaDelimitedList",
      "Default": "web-app-demo-ext,web-api-demo-ext"
    }
  },
  "Resources": {
    "AppAutoScalingGroup": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": {
          "Ref": "AZs"
        },
        "LoadBalancerNames": {
          "Ref": "LoadBalancers"
        }
      }
    }
  }
}