Support adding a hosted internal route53 zone

[brentley]

This is useful when creating an internal ALB to route traffic to backend services. I'm able to do this in my example services using this custom cloudformation, but it would be nice to roll it up into a single parameter:

  mu-iam-common:
    Resources:
      CloudFormationRole:
        Type: AWS::IAM::Role
        Properties:
          Policies:
            - PolicyName: update-route53-backend
              PolicyDocument:
                Version: '2012-10-17'
                Statement:
                - Action:
                  - route53:CreateHostedZone
                  - route53:UpdateHostedZoneComment
                  - route53:ListQueryLoggingConfigs
                  Resource: '*'
                  Effect: Allow
  mu-target-backend:
    Resources:
      DnsBackend:
        Type: "AWS::Route53::HostedZone"
        Properties:
          Name: "internal.service"
          VPCs:
            -
              VPCRegion:
                Fn::Sub: ${AWS::Region}
              VPCId:
                Ref: VpcId

[cplee]

@brentley can you share more details about how this hosted zone is used in the rest of the application? Just want to understand a bit more about the use case.

[brentley]

Sure!

Basically, I'm trying to build this:

The Internal DNS domain is used to give the Backend ALB an easy to reference DNS domain. I happen to be using api.internal.service. So my frontend would reference it's backend by talking to api.internal.service/whatever and ALB would direct the traffic to the appropriate set of services.

[cplee]

Makes perfect sense, thanks!

[brentley]

I ended up moving this into an extension: https://github.com/brentley/example-demo/blob/master/backend-service/common-iam.yml

along with setting up a 2nd ALB for the backend services: https://github.com/brentley/example-demo/blob/master/backend-service/elb.yml

[cplee]

@brentley would this still be necessary if #299 was implemented (Native ECS Service Discovery)?

[cplee]

Addressed in #299