How to create a AWS LB Listener from Cloud Formation that returns a fixed response?

Question

The LB configuration in the AWS Console allows to create a listener with the Default Action and the fixed Response option allows to specify HTTP return code. Now I want to edit this to support non-forwarding operation, below is the sample cloud formation:

MyServicesLoadBalancerListener:

    Type: AWS::ElasticLoadBalancingV2::Listener

    Properties:

        LoadBalancerArn: !Ref MyServicesLoadBalancer

        Port: 80

        Protocol: HTTP

        DefaultActions:

            - Type: forward

              TargetGroupArn: !Ref MyServicesTargetGroup

How can I do this with CloudFormation?

Answer 1

Use the below code and modify it according to your requirements, this should replicate the fixed response.

MyServicesLoadBalancerListener:

  Type: AWS::ElasticLoadBalancingV2::Listener

  Properties:

    LoadBalancerArn: !Ref MyServicesLoadBalancer

    Port: 80

    Protocol: HTTP

    DefaultActions:

      - Type: fixed-response

        FixedResponseConfig:

          ContentType: "text/plain"

          MessageBody: "You've reached the listener! Congrats!"

          StatusCode: "503"

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