Is there a way to connect a Application Load balancer from my frontend cluster to a Classic Load balancer created by backend cluster in AWS

Question

I have a public and private cluster. My frontend application is in public cluster and Backend in private cluster. Each cluster has 2 worker nodes each.

Now, we want to route the traffic from FE to BE. For ex: /api/sme/apple should connect to an application, /api/sme/orange should connect to another application which are exposed as a service in kubernates. We have given type: Load balancer in service so the private cluster on deployment creates Classic load balancers. The front end has an ingress file through which an ALB is created.

Now, we are trying to route the traffic from ALB through target groups via Listeners to CLBs in private cluster. Is this possible in AWS? If yes, how?

Appreciate your time and help in advance.

Answer 1

Its not possible, at least not easily. CLB does not have static IP addresses . You could temporary connect your ALB to CLB by using targets by private IP, but this won't be stable, as CLB IP addresses can change and you have no control over it.

Ideally you should be using NLB for static IP addresses. If not you have to develop a custom solution which will be checking for the CLB IP addresses and update the target groups accordingly. Something as shown here .

If you require such functionality, you should be using