* As a cloud operator, I want to be able to upgrade my cloud with custom roles with minimal service/workload interruption so that I can keep my cloud up-to-date and keep my SLA. * As a cloud operator, I want to have possibility to define what roles are going to be upgraded so that I can minimize service downtime. (understanding some limitations like ""control plane services need to be upgraded at the same time"") * As a cloud operator, I want to be able to upgrade in steps and keep operational cloud in-between steps so that I can mitigate risks and minimize service downtime. * As an OpenStack developer, I want to have full control on my service deployment & lifecycle management scripts and plug it into the framework so that I can independently maintain the code." Large impact. Composable services was a big feature and this will require a fair bit of testing to accommodate that