Missing Support for ForwardConfig in AWS::ElasticLoadBalancingV2::ListenerRule

[MattGirolami]

cfn-lint version: (cfn-lint 0.26.0)

Description of issue.
Receive a rule failure when using a ForwardConfig in a Listener Rule to configure weighted target group traffic routing. I believe the spec file is missing the ForwardConfig option.

E3002 Invalid Property Resources/ListenerRule1/Properties/Actions/0/ForwardConfig

Please provide as much information as possible:

• Template linting issues:
  • Please provide a CloudFormation sample that generated the issue.

AWSTemplateFormatVersion: '2010-09-09'
Parameters:
  TargetGroup1:
    Type: String
  TargetGroup2:
    Type: String
  Listener:
    Type: String
Resources:
  ListenerRule1:
    Type: AWS::ElasticLoadBalancingV2::ListenerRule
    Properties:
      Actions:
        - Type: forward
          ForwardConfig:
            TargetGroups:
              - TargetGroupArn: !Ref 'TargetGroup1'
                Weight: 1
              - TargetGroupArn: !Ref 'TargetGroup2'
                Weight: 1
      Conditions:
        - Field: path-pattern
          Values:
            - foo
      ListenerArn: !Ref 'Listener'
      Priority: 99

• If present, please add links to the (official) documentation for clarification.

https://aws.amazon.com/blogs/aws/new-application-load-balancer-simplifies-deployment-with-weighted-target-groups/

• Validate if the issue still exists with the latest version of cfn-lint and/or the latest Spec files

Exists in version 0.26.0 and after updating specfile with cfn-lint -u

[kddejong]

Confirmed. @PatMyron should we patch this in or do you want to check if it will be fixed soon. I'm submitting a pull request with the version 10.1.0 and it is also not in that one.

[PatMyron]

Actually don't even see that property documented yet or any mention in the release history

aws-cloudformation/cloudformation-coverage-roadmap#285

@MattGirolami did that template successfully deploy?

There was some CloudFormation work involving ForwardConfig recently though, so I think it's another case of #1219 if the template deploys successfully

[MattGirolami]

@PatMyron - Yes, the example template deploys successfully. I'm actively using ForwardConfig in production to weight traffic between multiple target groups

[PatMyron]

cfn-lint --update-specs should fix this now