gitolite/doc/2-admin.mkd
Sitaram Chamarty 396bfaa3b9 gl-auth now checks for and run a hook called 'gl-pre-git'
see sample code for motivation; other uses at your discretion
2011-03-05 12:23:17 +05:30

15 KiB

administering and running gitolite

In this document:


please read this first

Unless you know what you're doing, do not do anything manually on the server, like adding new repositories or users or changing the access control rules. Things will break. For example, if you manually create a repo on the server, it will not have the required "update" hook, without which there is no access control for pushes.

Most normal (day-to-day) gitolite admin work is done by cloning the gitolite-admin repo from the server to your workstation, making changes to the clone, and pushing those changes back.

The installation steps in the previous section include the steps to do this clone, so you should already have one on your workstation, in ~/gitolite-admin. You can of course clone it anywhere else you want and use that clone.

Either way, make sure you cd into this clone first.

Note: some of the paths in this document use variable names. Just refer to ~/.gitolite.rc for the correct values for your installation.

Once you've cloned it, you're ready to add users and repos.

adding users and repos

  • ask each user who will get access to send you a public key. See other sources (for example here) for how to do this

  • rename each public key according to the user's name, with a .pub extension, like sitaram.pub or john-smith.pub. You can also use periods and underscores

  • copy all these *.pub files to keydir in your gitolite-admin repo clone. You can also organise them into various subdirectories of keydir if you wish, since the entire tree is searched.

  • edit the config file (conf/gitolite.conf in your admin repo clone). See doc/gitolite.conf.mkd in the gitolite source for details on what goes in that file, syntax, etc. Just add new repos as needed, and add new users and give them permissions as required. The users names should be exactly the same as their keyfile names, but without the .pub extension

  • when done, commit your changes and push. Any new repos you specified will automatically be created (empty, but clonable) and users' access will be updated as needed.

using hooks

custom hooks

You can supply your own, custom, hook scripts if you wish. Install gitolite as usual, then:

  • if you installed using "from-client" method (gl-easy-install):
    • go to the gitolite source clone from which you did the original install
    • add your new hook into "hooks/common"
    • run src/gl-easy-install with the same arguments as you ran the first time
  • if you installed using one of the other methods
    • go to ~/.gitolite/hooks/common on the server and put your new hook there
    • now run "gl-setup" again

You can use this procedure to install new hooks as well as to update hooks that you had previously installed.

VERY IMPORTANT SECURITY NOTE: the update hook in hooks/common is what implements all the branch-level permissions in gitolite. If you fiddle with the hooks directory, please make sure you do not mess with this file accidentally, or all your fancy per-branch permissions will stop working.

"gl-post-init" hook

Sometimes it is necessary to do something whenever a new repo is created. If you need this functionality, just supply a hook called "gl-post-init" with whatever code you want in it.

"gl-pre-git" hook

Although git has lots of nice hooks you can tap into, they all run only on a push. There's nothing that runs on a fetch or a clone, and there's no way to run something before git-receive-pack or git-upload-pack, (as the case may be) are invoked.

That's what the gl-pre-git hook is for. If an executable hook called gl-pre-git is present, it will be invoked with the current directory set to repo.git, and with a single argument which will be either R or W depending on what the client is trying to do. The environment variables GL_USER and GL_REPO are available. STDOUT will be forced to STDERR before it is called, to avoid confusing the client.

If the code returns anything other than 0, gitolite will terminate the operation (i.e., not run git at all), just like many git hooks do, so make sure you end with exit 0 or equivalent.

hook chaining

Gitolite basically takes over the update hook for all repos, but some setups really need the update hook functionality for their own purposes too. In order to allow this, Gitolite now exec's a hook called update.secondary when it's own "update" hook is done and everything is ready to go.

You can create this update.secondary hook manually on selected repos on the server, or use the mechanism in the previous section to make gitolite put it on all your repos.

Similarly, gitolite also takes over the post-update hook for the special "gitolite-admin" repo. This hook will also chain to a post-update.secondary if such a hook exists. People wishing to do exotic things on the server side when the admin repo is pushed should see doc/shell-games.notes for how to exploit this :-)

Finally, these names (update.secondary and post-update.secondary) are merely the defaults. You can change them to anything you want; look in conf/example.gitolite.rc for details.

environment variables available to hooks

The following environment variables are set, and may be useful for any custom processing you wish to do in your hook code:

  • GL_USER -- the user doing the push
  • GL_REPO -- the reponame
  • GL_REPO_BASE_ABS -- the absolute base path where all the repos are kept

The following variables are also set, but are generally less useful:

  • GL_BINDIR -- where all the binaries live
  • GL_ADMINDIR -- common directory for many gitolite things

other features

moving pre-existing repos into gitolite

One simple way to add a pre-existing repo to gitolite is to let gitolite create it as a brand new repo as in the previous section, then do the following:

cd your-copy-of-the-repo
# make sure all the branches are correct and no extra stuff, "temp"
# branches, etc., are present
git push --all git@server:reponame
git push --tags git@server:reponame

(You could also use "git push --mirror" instead of separately doing branches and tags, but that will carry across your remote refs also, and typically you may not want that. Anyway please do a git ls-remote git@server:repo to make sure all the stuff you want went through, and is named correctly).

All this is actually very simple and easily done. However, if you have many existing repos to add, this can be time-consuming and error-prone. Here's how to take a bunch of existing repos and add them to gitolite:

  • make sure they're bare repos ;-)

  • log on to the server and copy the repos to $REPO_BASE (which defaults to ~/repositories), making sure that the directory names end in ".git".

  • back on your workstation, add each repo (without the .git suffix) to conf/gitolite.conf in your gitolite-admin repo clone. Then add, commit, push.

moving the whole thing from one server to another

[NOTE: I would appreciate help testing these instructions]

Just copying everything won't work unless everything on the new server is exactly the same. I suggest you don't try it unless you know what you're doing.

Assumptions

  • you have not changed $REPO_BASE on either of the servers; if you did, substitute accordingly
  • the admin's name is "YourName" -- again, substitute accordingly!
  • the "hosting user" on both servers is "git". Substitute whatever you're actually using (for example, if you're installing using RPM/DEB, this would be "gitolite")

There are many ways of doing this, but the most generic set of steps are given below. Please follow all the steps; do not skip or improvise! Ask me if things are not clear -- you can help me fine tune this document :-)

  • (old server) disable the old server so your users will not push any changes to it. There are several ways to do this, but the simplest is to insert this line at the top of ~/.gitolite.rc on the old server:

    exit 1;
    
  • (new server) copy the repos to the new server, except the gitolite-admin repo and files called gitolite-hooked in the hooks directory of each repo.

    That sounds complicated but it's not. It's just:

    cd $HOME
    rsync -a olduser@oldhost:repositories .
    mv repositories/gitolite-admin.git $HOME/old-gitolite-admin.git
    find repositories -name gitolite-hooked | xargs rm
    
  • (workstation) if your old server was installed using the "from-client" method, and you intend to use the same method to install the new server, then

    • edit ~/.ssh/config and change the line that says host gitolite to host old-gitolite, or in fact anything that does not match the string "host gitolite" :-)
  • (workstation, new server) install gitolite normally on your new server. Use whatever install method suits you, but you must use the same name for the admin ("YourName" in the install instructions). You may use a different keypair if you need to, or use the same one that currently gets access to the old server.

  • (new server) edit the ~/.gitolite.rc file to match the settings on the old server, if needed. Do not copy the entire file outright -- some of the variables (notably GL_PACKAGE_CONF and GL_PACKAGE_HOOKS) are installation dependent and should not be touched! Do a diff or a vimdiff and copy across only what you know you changed on the old server.

  • (workstation) push the config to the new server. To do this, go to your admin clone, and:

    • if you used a different keypair when installing to the new server, copy that pubkey to this clone into keydir/Yourname.pub, then add and commit the change to the pubkey

      cd gitolite-admin
      cp path/to/new/YourName.pub keydir/YourName.pub
      git add keydir
      git commit -m "new server, new key"
      
    • if you did not use a different keypair, just make a dummy commit

      git commit -m "new server" --allow-empty
      
    • set the URL for the new server

      git remote --set-url origin git@newserver:gitolite-admin
          # if you used easy install this will be "gitolite:gitolite-admin"
      
    • push the config, including past history

      git push -f
      

And that should be that!

specifying gitweb and daemon access

This is a feature that I personally do not use (corporate environments don't like unauthenticated access of any kind to any repo!), but someone wanted it, so here goes.

Gitolite has two pre-defined, "special", usernames: daemon and gitweb.

To make a repo or repo group accessible via "git daemon", just give read permission to the special user "daemon". Similarly, give read permission to gitweb to allow the gitweb CGI to show the repo. Something like this:

repo    foo bar baz
    R   =   gitweb daemon

This gives you a quick way to offer multiple repos up for gitweb and/or daemon access.

However, setting a description for the project also enables gitweb permissions so you can do it that way if you want. Of course in this case you have to deal with each repo separately. Add lines like this to gitolite.conf:

foo = "some description"
bar = "some other description"
baz = "yet another description"

You can also specify an owner for gitweb to show, if you like; for example I might use:

gitolite "Sitaram Chamarty" = "fast, secure, fine-grained, access control for git"

Note that gitolite does not install or configure gitweb/git-daemon -- that is a one-time setup you must do separately. All gitolite does is:

  • for daemon, create the file git-daemon-export-ok in the repository
  • for gitweb, add the repo (plus owner name, if given) to the list of projects to be served by gitweb (see the config file variable $PROJECTS_LIST, which should have the same value you specified for $projects_list when setting up gitweb)
  • put the description, if given, in $repo/description

The "compile" script will keep these files consistent with the config settings -- this includes removing such settings/files if you remove "read" permissions for the special usernames or remove the description line.

Please note that giving permissions to these special users via @all (that is, using either repo @all or R = @all), will not work unless you set the rc-file variable $GL_ALL_INCLUDES_SPECIAL to 1. Also, NOTE that giving them read access to repo @all means the gitolite-admin repo is also accessible. It is upto you to decide if that is OK in your environment.

custom git config

The custom hooks feature is a blunt instrument -- all repos get the hook you specified and will run it. In order to make it a little more fine-grained, you could set your hooks to only work if a certain "gitconfig" variable was set. Which means we now need a way to specify "git config" settings on a per repository basis.

[Note: this feature is disabled by default. Read the comments around a variable called GL_GITCONFIG_KEYS in the rc file, then set it to some appropriate value, to enable this feature.]

Thanks to Teemu (teemu dot matilainen at iki dot fi), gitolite now does this very easily. For security reasons, this can only be done from the master config file (i.e., if you're using delegation, the delegated admins cannot specify git config settings).

Please see doc/gitolite.conf.mkd for syntax. Note that this only supports the basic forms of the "git config" command:

git config              section.key value   # value may be an empty string
git config --unset-all  section.key

It does not (currently) support other options like --add, the value_regex, etc.