The only form of external userbase support that our Cloud (formerly OnDemand) JIRA and Confluence support at the moment is sourcing the userbase (and authenticating users against) Google Apps. Docs are at Managing Users and Groups with Google Apps.
However, technically, at the other side, Crowd supports being the SSO provider for Google Apps (documentation: Crowd's Configuring the Google Apps Connector).
In theory, it's possible that in this way you could get Cloud JIRA and Confluence to talk to Server Crowd (i.e. that you host) via Google Apps, but I haven't heard of any customer going down this path; you'd probably be "swimming upstream", to say the least.
Typically people who go down this line of reasoning want to connect to their Server Crowd in order to expose users from their LDAP server to our Cloud products; if that's your situation, you may like to vote on AOD-1837 - Support LDAP integration with OnDemand.
We're excited to announce the release of a long-requested feature on Statuspage. Now visitors to your status page can subscribe to get notified in Slack when you report an incident or maintenance. Th...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events