Currently we are using Jira, Confluence and Bitbucket on premise.
Confluence and Bitbucket are using the Crowd service which is offered by Jira. Our Jira is configured that Microsoft Active Directory and the built in directory are merged. This way users need to be administered in the Jira userdirectory or Active Directory only.
We consider migrating our Bitbucket into Cloud because it's user tier of 10 has become a bit small for our purposes.