1. A method of implementing a control plane for services in a computer system, comprising: executing a service host process on a software platform of a host computer, the service host process including a framework that provides a plurality of functionalities; creating a service instance as an object in the service host process based on a specification of a service, the service instance including a representational state transfer (REST) application programming interface (API), the specification defining declared options for the service; selectively enabling one or more of the plurality of functionalities provided by the framework for use by the service instance based on the declared options for the service; and processing requests for the service through the REST API of the service instance, the service instance using one or more of the enabled functionalities provided by the framework in response to the requests.