FreeIPA - I wish more people knew about this. You can tie a public SSH key to a user (users can also self-register them) and it is automatically recognized on a

FreeIPA - I wish more people knew about this. You can tie a public SSH key to a user (users can also self-register them) and it is automatically recognized on all hosts joined to the IPA domain, if you want to limit who has access to what the integrated RBAC facilities are there to handle that as well.