OPENSTACK
https://en.wikipedia.org/wiki/OpenStack#Compute_(Nova)
Is based in leaf and spine topology. Components:

• Neutron - network : 'Nuage VSP' an evolved version of it. Basically NSG == microsegmentation ~= neutron
• Nova : compute
• Glance : images
• Swift : storage
  • Ceph : distributed storage
  • Cinder : block storage
• Keystone : identity

Well known, working, distributions:

• Red Hat OpenStack

Interesting:

• Organization that built openstack private cloud and documented it white_paper

References:

• https://dzone.com/articles/openstack-core-components
• https://blog.ipspace.net/2017/03/worth-reading-building-openstack.html

Microsegmentation (as per 2021) is just packet filters pushed with dot1x. Access groups.