Fuel will be able to deploy OpenStack which will use VMWare vCenter as a hypervisor and VMWare NSX as a network virtualisation backend.
Fuel 5.0 has a limited support of vCenter as a hypervisor and no NSX support at all, but OpenStack can be integrated with both these components. There are two other blueprints already about vCenter support improvements  and introducing a basic NSX support . But both features cannot be used simultaneously without some additional work now. If a user has already paired vCenter Cluster and the NSX platform (or multiple pairs vCenter + NSX) he should be able to manage them by OpenStack.
After the blueprints  and  mentioned above would be implemented, there will be a possibility to enable both features deployed simultaneously. It’s mostly an administrative work needed because all the manifests will be ready, and we need just to allow a simultaneous use of the features somewhere in Release description.
We can do nothing, but a user will not be able to use his already paired vCenter + NSX environment as a hypervisor for OpenStack.
No data models modifications needed.
No REST API modifications needed.
I see no objections about upgrades. NSX Neutron plugin is a part of official set of plugins. Compute VMWareVCDriver is also official driver. So any upgrades should be done in a common way.
No additional security modifications needed.
Little modifications of the Cluster Creation Wizard needed.
There should be no significant changes in Puppet modules. Most of the work should be done on the Nailgun/UI side.
Release upgrades should be covered by blueprints ,  mentioned above.
No extra developer impact needed.
Acceptance Criteria: * User should be able to deploy environment with parameters: host OS: CentOS / Ubuntu OS; deployment mode: simple, HA; roles: different roles are supported due to vCenter as hypervisor and NSX plugin in simultaneous interrelation with required settings through Fuel UI; * All operations with environment which are provided through Fuel UI must be available for user; * NSX and vCenter must be stable for all destructive tests that we already have for these features; * OSTF tests related to these features must be passed: especially ‘smoke’, ‘sanity’, ‘ha’ groups; * Network connectivity test must be passed; * Manual testing is now a high priority part of acceptance testing using checklists according to acceptance criteria above; * A set of automatic tests will be implemented for this feature with 50% coverage of system tests.
The documentation should describe how to set up vCenter and NSX for a simple test environment. A reference architecture of the feature should also be described.