Resource tags don't propagate to frontend NLB

[cristicalin]

Bug Description
When configuring frontend NLB, the resource tags should propagate to the NLB and NLB TargetGroups but currently they do not, only the standard tags are set on the frontend NLB.

Steps to Reproduce

• Step-by-step guide to reproduce the bug:
• create an ingress with frontend NLB configured and set the alb.ingress.kubernetes.io/tags annotation
• check the resulting ALB and verify the tags are applied
• check the resulting FrontEnd NLB and verify the tags are not applied

Expected Behavior

The NLB should have the same tags configured in the alb.ingress.kubernetes.io/tags annotations or there should be a corresponding alb.ingress.kubernetes.io/frontend-nlb-tags annotation to allow us to configure extra tags on the frontend NLB.

Actual Behavior

No extra tags can be set on Frontend NLBs with version 2.13.3 of the controller.

Regression
Was the functionality working correctly in a previous version ? [No]

Current Workarounds

Environment

• AWS Load Balancer controller version: 2.13.2
• Kubernetes version: v1.31.9-eks
• Using EKS (yes), if so version?: v1.31.9-eks-5d4a308, aws-lb-controller deployed through argocd, not cluster add-on.
• Using Service or Ingress: Ingress
• AWS region: eu-west-1
• How was the aws-load-balancer-controller installed:
  • helm chart installed through argocd, no special parameters, using IRSA
• Current state of the Controller configuration:
  • not relevant
• Current state of the Ingress/Service configuration:
  • not relevant

Possible Solution (Optional)

Propagate resource tags to the frontend NLB or add another annotation to control the tagging of the frontend NLB .

Contribution Intention (Optional)

• Yes, I'm willing to submit a PR to fix this issue
• No, I cannot work on a PR at this time

Additional Context

[cristicalin]

I've also tried to set the tags via the IngressClassParams mechanism but they still do not propagate to the Frontend NLB.

[shraddhabang]

@cristicalin Thank you for reaching out to us. You are right we are not supporting the tag propagation at the moment for frontend NLBs. We can add this support through s dedicated annotation like you suggested. If you are willing to contribute, we will support it. :)

[0xlen]

@shraddhabang @cristicalin I'm interested to work on this feature and submit PR. Please let me know if i can contribute to this issue.

Also - would be great if you can help me understand how frond-end NLB be added, was that configured by alb.ingress.kubernetes.io/enable-frontend-elb?