Service discovery can happen in various ways, from DNS lookup to more sophisticated scenarios where the lookup is part of business logic, providing different endpoints depending on the situation. It generally encapsulates addressing external systems from the application's concerns. Ideally, the application logic only names the logical service it needs to communicate with, and the actual lookup is performed externally.

It depends on the used environments and runtime which possibilities enterprise developers have. Container technologies offer functionality to link services by names, taking away work and responsibility from the application. The clients connect against the link or service names as hostnames, which are resolved by the container technology.

This approach works both for Docker containers and container orchestration such as Docker Compose, Kubernetes, or OpenShift. All communication concerns solely use logical service names and ports to establish connections. This matches the 12-factor principles as well.

Since the lookup work is performed in the environment, the applications will only specify the desired service names. This is true for all outward communication, such as HTTP connections, databases, or message hubs. Chapter 5, Container and Cloud Environments with Java EE demonstrated examples for this.