Client controls require URLs to connect against in order to integrate external services. The URLs traditionally have been configured in files, which potentially differed in various environments. In an orchestrated environment the application can resolve external services using a logical name, via DNS. The following code snippet shows how to connect against the cloud processor application:

@ApplicationScoped
public class HelloCloudProcessor {

    private Client client;
    private WebTarget target;

    @PostConstruct
    private void initClient() {
        client = ClientBuilder...
        target = client.target("http://cloud-processor:8080/processor/resources/hello");
    }

    public String processGreeting() {
        ...
    }
}

The same holds true for other URLs, for example datasources definitions. The application server configuration can simply point to the name of the database service and use it to resolve the corresponding instance at runtime.