ONAP introduction
ONAP from the milky way point of view
From the very optimistic perspective ONAP is an independent system in the outer space that provides interfaces for User, Admin and OSS/BSS system in the North and xNF in the South and uses interfaces provided by NFVI and xNF.
ONAP deployed on kubernetes
ONAP has to be deployed on some infra. Currently it's kubernetes.
ONAP deployed on kubernetes with external databases
As most of applications ONAP requires some persistence layer in form of databases. As ONAP follows micro-service architecture principle in theory each component could ship its own database but in practice in commercial deployments its desired to configure ONAP to use external DB engines already existing in operators infrastructure.
ONAP deployed on kubernetes with external databases and external IAM
Obviously it's hard to imagine operator that would like to have one more identity DB to managed specifically for ONAP thus ONAP should have the ability to integrate with external IAM system.
ONAP deployed on kubernetes with external databases and external IAM and external CA
Most of the operators probably already have Certificate Authority server running in their network and a requirement that all services should present a valid certificate signed by this CA. This means that ONAP should provide the ability to integrate with external CA instead of shipping own one.