Git support in Trac

Since version 1.0, Trac features built-in support for ​Git as a VersionControlSystem for Trac.

Please note that we're still considering the level of performance to be sub-optimal, so it might not work for you. Small to medium sized repositories should be handled reasonably well, however.

Features

• Browsing source code via the TracBrowser
• Viewing the change history of a file or directory using TracRevisionLog
• Performing diffs between any two files or directories
• Displaying changes in the TracTimeline
• (Optionally) caching TracChangeset information in Trac's database
• Caching Git commit relation graph in memory
• Search change descriptions via TracSearch
• Annotation support, also known as "blame" operation
• Interpretation of 40-character wide hex-strings as sha1 commit checksums

Git

Download and Installation

You need to have the git command line tools installed. You can download Git itself from ​Git:Download.

We try to maintain backward compatibility with versions of Git from 1.5.6 to the latest. It's better use a recent version, however.

Configuration

The configuration has to be done mainly on the Trac side, there's nothing required to do on the Git repository side. Some advanced use cases necessitate however to install a post-receive hook in the Git repository (see below).

Note that the repository should be made accessible as a local repository. Thanks to the distributed nature of Git, that's always possible. If the repository is not already local, simply git clone it.

Trac

The Trac Git support is included with Trac since 1.0 as an optional component: tracopt.versioncontrol.git.

You simply have to explicitly enable the plugin in TracIni:

[components]
tracopt.versioncontrol.git.* = enabled

The web administration interface can also be used for this, using the General / Plugins panel.

Setting up a Trac environment

You can either reuse an existing Trac environment, or create a brand new one.

New environment

For general instructions, see TracInstall.

When creating a new environment with TracAdmin initenv command,

• for the repository type, specify git instead of the default svn.
• for the repository directory, specify the location of the Git repository (for Trac < 1.0.2 the path of a non-bare repository will end in a .git directory).

Your <trac_environment>/conf/trac.ini configuration file should have a [trac] section similar to the following (Trac < 1.1.3):

[trac]
repository_type = git
repository_dir = /path/to/my/git/repository/.git

or a [repositories] section similar to the following (Trac 1.1.3 and later).

[repositories]
.type = git
.dir = /path/to/my/git/repository/.git

Specify the location of the git executable, in case it's not the default /usr/bin/git. As an example, for Windows:

[git]
git_bin = C:/Dev/msysgit/bin/git.exe

See also #settings below.

Adding a Git repository to an existing environment

If all you need is to work with a single git environment, it is enough to modify the [repositories] section in your trac.ini so that it contains the appropriate values for the .type and .dir options, like in the above example.

However, if you need more than one git repository, or if you want to keep your old Subversion repository as the default repository in order to not break the TracLinks pointing to source files and changesets contained in that repository, you can add non-default repositories.

There are basically two ways to do that, either via the [repositories] section of the TracIni file, or via the web administration interface using the Version Control / Repositories panel. For more details, see the TracRepositoryAdmin.

Fine tune trac.ini settings

Besides the git_bin setting discussed above, there are a few more Git specific settings that can be specified in TracIni [git] section.

Setting up post-receive hooks

If you want to benefit from some advanced features for your repository, like automatically update your tickets based on the content of the commit messages (CommitTicketUpdater) or smart caching, then you need to create or modify the ​post-receive hook in the .git/hooks repository so that it calls trac-admin repository appropriately.

enable post-receive hook functionality on your repository, put a post-receive script into your_repository/.git/hooks/.

TODO Include post-receive scripts attached to ​th:GitPlugin#post-receivehookscripts

You can then enable the CommitTicketUpdater functionality in your trac.ini by adding:

tracopt.ticket.commit_updater.* = enabled

to the [components] section.

Troubleshooting

• Don't forget to enable the plugin:

  [components]
  tracopt.versioncontrol.git.* = enabled 
  

• For Trac < 1.0.2, the repository_dir in the configuration section needs to be the .git repository directory (i.e. the one containing the file HEAD and config), not the working tree directory that holds the .git folder (#11297). However, a bare repository will have these control files in the top-level directory and will not contain a .git directory.
• Wrong permissions may also be the cause of the error GitError: GIT control files not found, maybe wrong directory?. Make sure the repository path is accessible via git by the tracd process.
• If you are noticing a slow down in trac with a repository above 500 commits, try disabling the caching. It seems to bog things down as a repo grows(!)
• If you don't see the shortrev and commit branch, you probably have caching enabled (cached_repository = true, persistent_cache = true). Set those to false.
• For Trac < 1.0.2, the source browser can throw an error when trying to kill a git log process; it's not clear why it should be an error for the process to have completed. This problem manifests as a stack trace with terminate_nix at the end (#10958).

Known Issues

#10666

Setting fine grained permissions using AuthzPolicy does not work

#11061

TypeError: Git object id must be byte or a text string, not: int

#11992

Allow git commit hashes to be abbreviated to 7 characters

#13169

GitNode.get_content() read entire of a file into memory even if it is huge

History

The Git support was initially developed as a plugin by Herbert Valerio Riedel for Trac 0.10-0.13. See ​TracHacks:GitPlugin / ​GitHub. For Trac 1.0, it has now been included as an optional component (#10594), and is maintained and developed here.