Due to limitations with Confluence Cloud hosting (addons basically), we want to self-host Confluence Server.
However we have a large JIRA Cloud installation already that uses Google Apps for authentication.
What we want to do is use the JIRA Cloud installation user base, groups and authentication in the self hosted Confluence Server.
Its not clear if this is possible. It looks like you can, but it also looks like you can't. Authentication just seems to be a little bit too black-box (hidden behind the scenes).