I only glanced at your repo, but it sounds like you have an ingress problem. That is, you don't really have two pods communicating, but you need to hit your backend service from outside the cluster. Under the hood this is always accomplished with a node port on a service- a single port on any node in your cluster will forward to said service.
k8s has integration with cloud providers like aws to hook all this up for you, but all its doing is setting up an elb which load balances to that port on every node in your cluster.
I only glanced at your repo, but it sounds like you have an ingress problem. That is, you don't really have two pods communicating, but you need to hit your backend service from outside the cluster. Under the hood this is always accomplished with a node port on a service- a single port on any node in your cluster will forward to said service.
k8s has integration with cloud providers like aws to hook all this up for you, but all its doing is setting up an elb which load balances to that port on every node in your cluster.