We do have a Identity & Access Management System in place. This directory is basically the only directory which has all users (we're a production company and quite a few of our users do not need an Active Directory Account). The IAM directory is not LDAP enabled.
1) We do want to be able to show all user information in Confluence (address book) also from the ones without AD account (they still have a phone number and need to be able to call each other). We're also using the information to build the org chart in confluence then.
2) We do want to create the user directory completely from IAM via either daily import or API
3) We do want to create the group mapping manually from the IAM system (people are ordering spaces via IAM and the system then creates the groups and memberships itself)
4) This now is the tricky part even though the users have been created manually we do want to have them authenticated via SAML2.0 & SSO (we use secureauth).
Summary : We do not want to attach a directory for user management but we want the users to be authenticated using SAML2.0 / secureauth device.
How should this be done? (I know this is not how the rest of the world does it anyhow this is the approach we have to take).