When configuring nova to connect to Neutron and Placement services, according to the https://docs.openstack.org/neutron/pike/install/controller-install-ubuntu.html#configure-networking-options (Install Guide), in /etc/nova/nova.conf under [neutron] and [placement] sections, apart from Keystone URL one also has to specify username and password entries. What is confusing to me is that the Install Guide shows username and password of the Neutron and Placement service accounts. Since Nova is the client here, should instead username and password of the Nova service account be used here instead?