Git is an open-source version control system designed to handle very large projects with speed and efficiency.

Git falls in the category of distributed source code management tools, similar to CVS, Subversion (svn), or Bazaar. Every Git working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server. Still, Git stays extremely fast and space efficient.

This article will focus on using Git with a subdomain on your (gs) Grid-Service.

The following Git packages are installed on the (gs) Grid-Service:

• git-core
  
• git-doc
  
• git-email
  
• gitweb
  
• git-svn
  

These packages provide core Git functionality as well as the ability to browse repository information on the web and bridge Git with Subversion.

The current installed version of Git is 1.5.4.1.

Creating a repository for use on your (gs) subdomain

The normal workflow when using Git is saving your work to a local repository on your personal computer and, when ready for publishing, "pushing" those changes to your "bare" repository.  Here are the steps needed for this process.

1. Add an alternate or subdomain to your service through the AccountCenter.  For this article we will use the descriptive name 'git.mt-example.com'.
2. On your personal computer make a directory and create your bare repository:

mkdir mt-example && cd mt-example
git init

3. Now create a meaningless test file that we will commit to the local repository:

touch .gitignore
git add .gitignore
git commit -m "just adding test gitignore file"

4. Create the "bare" clone named mt-example.git:

Before we can push our local Git repository to the Grid we have to create a bare clone.  A default git repository assumes that you’ll be using it as your working directory, so git stores the actual bare repository files in a .git directory alongside all the project files. Remote repositories do not need copies of the files on the filesystem unlike working copies. This is what “bare” means to git -- just the repository itself.

cd ..
git clone --bare mt-example mt-example.git
touch mt-example.git/git-daemon-export-ok

5. It's now time to upload the repository to your (gs) Grid-Service using scp.  Please make sure ssh is enabled in the AccountCenter:

scp -r mt-example.git serveradmin%mt-example.com@mt-example.com:domains/git.mt-example.com/html/mt-example.git

6. Login to your (gs) to complete the setup using ssh:

ssh serveradmin%mt-example.com@serveradmin@mt-example.com
cd domains/git.mt-example.com/html/mt-example.git
git --bare update-server-info
cd hooks
mv post-update.sample post-update
chmod a+x post-update

Your repository is now configured!!  At this point you and your contributors will now be able to push and pull content to your new repository.

Using your repository:

Pulling

New users can clone your repository directly from the Grid using http with the following command:

git clone http://git.mt-example.com/mt-example.git

Pushing

Now that we have a working repository both locally and on the Grid we can start using git to "push" new content.  Assuming you have added/updated new files locally you would use the following command to update your repository on the Grid from within your local mt-example directory:

git push ssh://serveradmin%mt-example.com@mt-example.com/home/#####/domains/git.mt-example.com/html/mt-example.git master 

Of course that is quite a lengthy command to use every time you want to push your files.  You can actually create a shortcut for the above using the git remote add function.  The following command matches up to the one above and uses the word grid as the shortcut name.  Make sure you are in your local mt-example directory first before running this command:

git remote add grid ssh://serveradmin%mt-example.com@mt-example.com/home/#####/domains/git.mt-example.com/html/mt-example.git 

Now you can simply push using the command:

 git push grid master

(Optional) Using gitweb

Gitweb is a CGI application that allows anyone to browse the history and content of your repository using a web browser.  If you would like to use this please follow the directions below.  You might also want to consider password-protecting this url.

1. Login to your (gs) Grid-Service using ssh and navigate to the cgi-bin directory for git.mt-example.com.

ssh serveradmin%mt-example.com@mt-example.com
cd domains/git.mt-example.com/cgi-bin 

2. Create a new cgi script named gitweb.cgi in the cgi-bin directory with the following contents.  Ensure that your path is correct:

#!/usr/bin/perl
$ENV{'GITWEB_CONFIG'} = '/home/#####/domains/mt-example.com/gitweb.conf';
exec '/usr/lib/cgi-bin/gitweb.cgi'; 

3.  Make this script executable using the chmod command:

chmod +x gitweb.cgi 

4. Copy the default configuration file from the server:

cd ..
cp /etc/gitweb.conf gitweb.conf 

5. Edit this gitweb.conf file.  The only required variable needed to be changed is $projectroot:

$projectroot = "/home/#####/domains/git.mt-example.com/html"; 

6. Copy over the static resources from our server:

cd html
wget http://s1.gridserver.com/git/git-favicon.png
wget http://s1.gridserver.com/git/git-logo.png  
wget http://s1.gridserver.com/git/gitweb.css   

7. In your web browser visit http://git.mt-example.com/cgi-bin/gitweb.cgi to view the interface and you should see your repository on the web!! 

For more information, see the INSTALL documentation for gitweb.

Notes/Supplemental Resources:

• User Manual
  
• Git for SVN users
  
• Git Documentation Index
  
• Git Command man pages
  

Revisions:

01-02-2008: Major rewrite of our first git article published in June 2008.