I think the reason the 'nova' user needs the 'admin' role is because neutron uses it to send a network allocation event back to nova. Nova should be configured by default to allow users with the 'service' role to do this operation and not require the 'admin' role.
I think the reason the 'nova' user needs the 'admin' role is because neutron uses it to send a network allocation event back to nova. Nova should be configured by default to allow users with the 'service' role to do this operation and not require the 'admin' role.