The machine, that you originally had hosting the git repos, is almost 99% still hosting those previous xcode server git repos, mine are still intact and there. They are just run by the git binariy, and are served via ssh commands.
If you have to setup a new git server, that's plastered all over the internet!
But normally all you have to do it have your ssh keys setup, init (on server) and create and init then push (on client)
A) This assumes you set your ssh keys up already
B) This assumes you had a past Xcode 6/7/8 Server with a symlink called:
/git -> pointing to /Library/Developer/XcodeServer/HostedRepositories
C) If not you can put it where you want as long as you have git running at least
This is all while as an admin or sudo su, or sudo bash, or sudo all command to get thru!
ON SERVER
cd /git # Goto git reservoir
mkdir -p repoTest.git # Make git dir
cd /git/repoTest.git # Go inside
git --bare init # Initialize repository
git config core.sharedRepository group # Update the git's config, group is keyword don't replace
chgrp -R <group-name> . # Change files and directories' group, I use: admin
chmod -R g+w . # Change permissions
chmod g+w objects/pack # If you get push errors
goto Xcode, and create a mac project on the server called repoTest
at ~/ or some convienant developer dirctory you use
ON CLIENT (with ssh/keys)
cd ~/repoTest
echo "# repoTest" >> README.md
git init
git add README.md
git commit -m "first commit"
git remote add origin ssh://<user_name>@<server_url>/git/repoTest.git
git push -u origin master
THEN DROP INTO SourceTree.app (HAHA)
Push Like Crazy Commit Checkout Branch etc etc
You should be good to go!
Hope this helps you guys out...
Laters...