In server-side discovery, when a service consumer makes a request, it makes it via a router or a load balancer running on a fixed or known location. This sort of router would then require a service registry (which could be built in the router) and forwards the request to an available service instance.
AWS Elastic Load Balancer (ELB) provides such an implementation. Kubernetes provides a proxy service which implements server-side discovery router.
Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications. It is also used extensively to orchestrate Docker containers.