1. A method, in a distributed service-oriented data processing system, for declarative service domain federation, the method comprising: receiving, in a planning engine of the federation server data processing system, a federation rule, a quality-of-service policy, and a service group definition; identifying, by the planning engine, a set of services based on the service group definition; generating, by the planning engine, a service visibility configuration and one or more service proxies based on the federation rule and the quality-of-service policy; deploying, by the federation server, the visibility configuration to one or more service domains comprising the individual services; and deploying, by the federation server, the one or more service proxies to connectivity middleware of the one or more service domains.