This tutorial is great and easy to get setup with Azure AD integrated for Jira: https://docs.microsoft.com/en-us/azure/active-directory/active-directory-saas-jiramicrosoft-tutorial
The only problem with it is, as outlined it requires that the usernames are in email address form within Jira, and stored in the local Jira internal directory.
What if I want to leverage all the existing usernames and keep them using local AD but leverage Azure AD only as a redundancy?
When trying this setup and test logging into Jira it says "User is not available in JIRA. Please contact your JIRA admin." I think this is because it's trying to use the email address returned as the username in the SAML query as the username in Jira, but we're using just the straight up username from active directory, not the full email.