`gitosis` -- software for hosting `git` repositories

Manage git repositories, provide access to them over SSH, with tight access control and not needing shell accounts.

Note

Documentation is still lacking, and non-default configurations (e.g. config file, repositories, installing in a location that is not in PATH) basically have not been tested at all. Basic usage should be very reliable -- the project has been hosting itself for a long time. Any help is welcome.

gitosis aims to make hosting git repos easier and safer. It manages multiple repositories under one user account, using SSH keys to identify users. End users do not need shell accounts on the server, they will talk to one shared account that will not let them run arbitrary commands.

gitosis is licensed under the GPL, see the file COPYING for more information.

You can get gitosis via git by saying:

git clone git://github.com/res0nat0r/gitosis.git

And install it via:

python setup.py install

Though you may want to use e.g. --prefix=. For Debian/Ubuntu users, the source is debianized.

Setting up

First, we will create the user that will own the repositories. This is usually called git, but any name will work, and you can have more than one per system if you really want to. The user does not need a password, but does need a valid shell (otherwise, SSH will refuse to work). Don't use an existing account unless you know what you're doing.

I usually store git repositories in the subtree /srv/example.com/git (replace example.com with your own domain). You may choose another location. Adjust to suit and run:

sudo adduser \
    --system \
    --shell /bin/sh \
    --gecos 'git version control' \
    --group \
    --disabled-password \
    --home /srv/example.com/git \
    git

This command is known to work in Debian and Ubuntu. Your mileage may vary. Under CentOS (and presumably RedHat) execute the following commands as root instead:

useradd \
      -r \
      -s /bin/sh \
      -c 'git version control' \
      -d /home/git \
      git

mkdir -p /home/git

chown git:git /home/git

You will need an SSH public key to continue. If you don't have one, you need to generate one. See the man page for ssh-keygen, and you may also be interested in ssh-agent. Create it on your personal computer, and protect the private key well -- that includes not transferring it over the network.

Next, we need to set things up for this newly-created user. The following command will create a ~/repositories that will hold the git repositories, a ~/.gitosis.conf that will be a symlink to the actual configuration file, and it will add the SSH public key to ~/.ssh/authorized_keys with a command= option that restricts it to running gitosis-serve. Run:

# sudo -iu git
git $ gitosis-init <FILENAME.pub
git $ exit
# (or just copy-paste the public key when prompted)

then just git clone git@SERVER:gitosis-admin.git, and you get a repository with SSH keys as keys/USER.pub and a gitosis.conf where you can configure who has access to what.

Warning

For now, gitosis uses the HOME environment variable to locate where to write its files. If you use sudo -u without -H, sudo will leave the old value of HOME in place, and this will cause trouble. There will be a workaround for that later on, but for now, always remember to use -H if you're sudoing to the account. Alternatively, you can use -i as above, which runs a full login shell.

You should always edit the configuration file via git. The file symlinked to ~/.gitosis.conf on the server will be overwritten when pushing changes to the gitosis-admin.git repository.

Edit the settings as you wish, commit and push. That's pretty much it! Once you push, gitosis will immediately make your changes take effect on the server.

Managing it

To add new users:

add a keys/USER.pub file
authorize them to read/write repositories as needed (or just authorize the group @all)

To create new repositories, just authorize writing to them and push. It's that simple! For example: let's assume your username is jdoe and you want to create a repository myproject. In your clone of gitosis-admin, edit gitosis.conf and add:

[group myteam]
members = jdoe
writable = myproject

Commit that change and push. Then create the initial commit and push it:

mkdir myproject
cd mypyroject
git init
git remote add myserver git@MYSERVER:myproject.git
# do some work, git add and commit files
git push myserver master:refs/heads/master

That's it. If you now add others to members, they can use that repository too.

Example configuration

Using git-daemon

Anonymous read-only access to git repositories is provided by git-daemon, which is distributed as part of git. But gitosis will still help you manage it: setting daemon = yes in your gitosis.conf, either globally in [gitosis] or per-repository under [repo REPOSITORYNAME], makes gitosis create the git-daemon-export-ok files in those repository, thus telling git-daemon that publishing those repositories is ok.

To actually run git-daemon in Ubuntu, put this in /etc/event.d/local-git-daemon:

For other operating systems, use a similar invocation in an init.d script, /etc/inittab, inetd.conf, runit, or something like that (good luck).

Note that this short snippet is not a substitute for reading and understanding the relevant documentation.

Using gitweb

gitweb is a CGI script that lets one browse git repositories on the web. It is most commonly used anonymously, but you could also require authentication in your web server, before letting people use it. gitosis can help here by generating a list of projects that are publicly visible. Simply add a section [repo REPOSITORYNAME] to your gitosis.conf, and allow publishing with gitweb = yes (or globally under [gitosis]). You should also set description and owner for each repository.

Here's a LightTPD config file snippet showing how to run gitweb as a CGI:

And a simple gitweb.conf file:

Note that this short snippet is not a substitute for reading and understanding the relevant documentation.

Contact

You can email the author at tv@eagain.net, or hop on irc.freenode.net channel #git and hope for the best.

There will be more, keep an eye on http://eagain.net/ and/or the git mailing list.

XingyongGuo/gitosis