Looking for setup steps for gitosis after installing from
If I remember correctly, Progit has an excellent chapter on that one.
I suggest looking into this page. It gives clear instructions about how to do the setup for Debian based (like ubuntu) systems.
First you create a new repository, then you check that out using the git client. This check out can be used to configure the server. But that is all very nicely explained on that page.
apt-get install gitosis should have created a new user on your system called "gitosis". Gitosis works by creating an admin repository in this users home folder, and to administrate git you clone that repository, make the changes you want and then push the changes back to the original repo.
To make gitosis create the admin repo, you probably need to create an ssh key pair and tell gitosis to use it for user authentication. Try
ssh-keygen -t rsa to create the key pair and copy the public part (id_rsa.pub) to a folder on the server that the gitosis user has read access to (/tmp should work). After that you can run
sudo -H -u gitosis gitosis-init < /tmp/id_rsa.pub to make gitosis initialize the admin repository.
When the admin repository has been created, you use the private part of the previously generated ssh (most probably called "id_rsa") key pair to authenticate your git client when cloning the admin repo.
To clone the admin repo, the following command can be used
git clone git@[servername]:gitosis-admin.git.
Now you can add the public keys for anybody that is supposed to have access to the git repositories to the admin repository.