I've been trying for hours to get a basic CodePipeline up and running with ECS Green/Blue. We're creating a prototype, so everything is in a single repo for now, and the `Dockerfile`, `taskdef.json`, `appspec.yaml` are all in a subfolder. I'm getting the following error:

`The ELB could not be updated due to the following error: Primary taskset target group must be behind listener arn:aws:elasticloadbalancing:eu-west-1:123:listener/app/api-lb/123/123`

I know there are Terraform modules for this, but I wanted to modify/extend this after it works, so I decided to start from scratch. Went through a dozen different articles, but I can't figure out what's wrong with my LB config.

All the Terraform files can be found here: https://github.com/zentered/terraform-ecs-green-blue-pipeline

Any hints on what I'm doing wrong? Thanks!