1. A computer-implemented method comprising: storing, in a cloud computing environment, in a shared identity store in a shared identity management system used by multiple identity domains that are isolated from each other, identities of a plurality of users associated with different identity domains within the multiple identity domains; creating a first identity domain through the shared identity management system; associating a first plurality of services with the first identity domain; sharing, among the first plurality of services, identities of a first set of users from the plurality of users managed by the shared identity management system; creating, through the shared identity management system, a second identity domain that is isolated from the first identity; associating a second plurality of services with the second identity domain; and sharing, among the second plurality of services, identities of a second set of users from the plurality of users managed by the shared identity management system, wherein the second set of users is different from the first set of users; in response to a request to provision an instance of a particular service to the first or second identity domain of the multiple identity domains, selecting, from a plurality of different role hierarchy templates that are associated with different services, a particular role hierarchy template that was associated with the particular service prior to receiving the request; and in response to the request, creating, in the first or second identity domain, a role hierarchy to map the first or second set of users to specific roles based on the particular role hierarchy template.