Detect owner of SSH key

Description

How to detect owner of SSH key in /var/opt/gitlab/.ssh/authorized_keys?

The only info is (1) "key-nn" in gitlab-shell cmdline and (2) optional key title at line end.

~"feature proposal"

Proposal

Provide userid in gitlab-shell arguments in authorized_keys, or add "search by ssh key" to /admin/users in webgui.