ALB does not get requests when using CNAME record, instead it is treated as an S3 request.

[barrydunne]

I have a working ALB that I can access using http://local-alb.elb.localhost.localstack.cloud:4566/
My goal is to have different host based rules on the listener to target different ECS services.

As a first step toward this goal I have created a hosted zone in R53 named aws-playground.local
Within that zone I have a CNAME record for test.aws-playground.local that points to local-alb.elb.localhost.localstack.cloud

Running dig on the LocalStack container shows it is available

dig @localhost test.aws-playground.local ANY

;; QUESTION SECTION:
;test.aws-playground.local.     IN      ANY

;; ANSWER SECTION:
test.aws-playground.local. 300  IN      CNAME   local-alb.elb.localhost.localstack.cloud.

On the LocalStack container I can run this command and get the expected response from the ALB

curl http://local-alb.elb.localhost.localstack.cloud:4566/test

I can also run this command and get the expected response from the ALB

curl -H "Host: local-alb.elb.localhost.localstack.cloud:4566" http://localhost:4566/test

But if I run this command I do not get a response from the ALB, instead I get a message saying "The specified bucket does not exist"

curl -H "Host: api.aws-playground.local:4566" http://localhost:4566/test

Outside of docker I have also added an entry in my local hosts file to point api.aws-playground.local to 127.0.0.1 and see the same behaviour.

Is it possible to use a custom domain to access an ALB in LocalStack?
I would be happy to disable the ability to access S3 buckets via domain if that was an option.