We got multiple k8s clusters on AWS (using EKS) each on its own VPC but they are VPC peered properly to communication to one central cluster which has an elasticsearch service that will collect logs from all clusters. We do not use AWS elasticsearch service but rather our own inside kubernetes.

We do use an ingress controller on each cluster and they have their own internal AWS load balancer.

I'm getting fluentd pods on each node of every cluster (through a daemonset) but it needs to be able to communicate to elasticsearch on the main cluster. Within the same cluster I can ship logs fine to elasticsearch but not from other clusters as they need to be able to access the service within that cluster.

What is some way or best way to achieve that?

This has been all breaking new ground for me so I wanted to make sure I'm not missing something obvious somewhere.