Extend TargetGroupBinding to allow lookup of target group by name rather than just arn #3586
Description
Is your feature request related to a problem?
I work on a project where we desire to:
- create load balancers and target groups via terraform and only manage their lifecycle via terraform
- use the Aws load balancer controller to expose some k8s services
- create individual helm chart deployments for each of our apps with TargetGroupBindings, so that they can be routed to via the relevant target group
Currently it is required for TargetGroupBindings (when the controller doesn't manage the load balancer itself) to map onto the required target group by providing the target group arn.
Because we won't necessarily know what the relevant target group arn will be ahead of time when we create our app helm charts, this makes it difficult to use TargetGroupBindings for our use case
Describe the solution you'd like
A description of what you want to happen.
TargetGroupBinding is extended with the ability to lookup the relevant target group by name - target group names are unique per region per account - https://docs.aws.amazon.com/elasticloadbalancing/latest/application/create-target-group.html
Describe alternatives you've considered
A description of any alternative solutions or features you've considered
We have considered other solutions, given our constraints around terraform management of target groups and load balancers, such as making our own custom controller, or generating the required helm values in our helm deploy pipeline, but both of these would be poorer solutions than simply extending this controller