In case anybody is interested, having a bare git repo on a server is as easy as:
# locally
ssh git@example.com
# server
mkdir repo.git
cd repo.git
git --bare init
# locally
git remote add origin ssh://git@example.com/home/git/repo.git
git push origin master
It has all the same working features as github
If it's your ssh server and it's single user you don't need to use the "git@" part at all.
Just store the repo and access it with your account.
The whole git@ thing is because most "forge" software is built around a single dedicated user doing everything, rather than taking advantage of the OS users, permissions and acl system.
For a single user it's pointless. For anyone who knows how to setup filesystem permissions it's not necessary.
I prefer to be explicit about which user is connecting to ssh.
There isn't much advantage that can be taken from O/S users and perms anyway, at least as far as git is concerned. When using a shared-filesystem repository over SSH (or NFS etc.), the actually usable access levels are: full, including the abilities to rewrite history, forge commits from other users, and corrupt/erase the repo; read-only; and none.