This module contains all the interfaces needed in registry and discovery. It also implements a direct registry, which you can hard-code services into the service.yml to simulate Consul or Zookeeper during development. Although this is for local development, many users are still using it during production when they have allocated services to the exact IP and port on virtual machines.
Currently, Consul and ZooKeeper are supported for external service registry and discovery.
The following section will focus on the DirectRegistry.
This is the most simple service to URL mapping—one serviceId map to exactly one service instance.