1. A method, comprising: receiving, by one or more computing devices and from an agent, associated with a private zone of computing resources, that facilitates communications between the one or more computing devices and at least a portion of computing resources of the private zone, a request to add the at least a portion of computing resources to a cloud of computing resources that is managed by the one or more computing devices and comprises shared computing resources and private computing resources; and responsive to the request and a determination that addition of the at least a portion of computing resources to the cloud is authorized: adding, by the one or more computing devices, the at least a portion of computing resources to the cloud; generating, by the one or more computing devices, an authentication token; and communicating, by the one or more computing devices and to the agent, the authentication token.