Berlin Brown and Software Development: Short primer, importing a SVN repository into a GIT one

Sunday, November 11, 2007

Short primer, importing a SVN repository into a GIT one

I wanted to convert parts of the Botlist project to GIT. Basically, I did just that. I saved the history from the Subversion repository and was able to import that into a new GIT repository. My entry will discuss the steps that I took to make that happen, also I work with several different remote machines so I hacked together a startup script for git-daemon.

Get GIT and install

I am working with an Ubuntu Dapper machine (yes, it is an older distro) and I didn't want to go through the hassle of using a very out of date version of git, so we are going to download the most recent git from kernel.org.

wget http://kernel.org/pub/software/scm/git/git-1.5.3.5.tar.gz
tar -xvf git-1.5.3.5.tar.gz

Pre configure and Installation

Actually, before running configure on the git source; you may need to get two
libraries.

On Ubuntu, I did the following:

sudo apt-cache search libsvn-core-perl
sudo apt-get install libsvn-core-perl
sudo apt-get install libcurl3-dev

In order for the git-svn to work, you will need the libsvn perl libraries. For working with http operations, you will need libcurl.

Run ./configure

At this point, you can start to build the git source; type ./configure at the command prompt and the subsequent make/install commands. Basically, standard steps for compiling and installing a typical linux source package.

./configure
make
sudo make install

Git is installed, now get the subversion project (history)

Assuming git was built properly, you should be able to import a subversion
project. I suggest creating a directory and then have git create the .git repository information in that particular folder.

sudo mkdir -p /usr/local/var/gitscm/botlist.git
cd /usr/local/var/gitscm/botlist.git
sudo git-svn clone http://openbotlist.googlecode.com/svn/trunk/openbotlist/

At this point, you will see verbose output of git creating the botlist repository.
That is all that is needed to create a repository from subversion, notice that the svn (.svn) working directory folder is not included in your git project.

Running the git-daemon at machine startup

Unlike other linux daemons, setting up git-daemon is pretty simple. At least for running the git daemon server under the git protocol. Basically, git-daemon is a server for hosting git repositories and this particular server defaults to running on port 9418. GIT also supports hosting repositories through HTTP.

Run whereis git-daemon to find out where the executable is located. It is up to you how to pass the git-daemon arguments, I used a simple wrapper bash script and launched git from there.


BASE_PATH=/usr/local/var/gitscm
/usr/local/bin/git-daemon --reuseaddr --verbose --base-path=${BASE_PATH} --export-all -- ${BASE_PATH}

[End of Script]
Change the base-path path according to where you want to store your git repositories. In the script above, gitscm is just a regular directory. The subdirectories (for example, botlist) are actual git repositories (that contain the .git directory). Create a symbolic link in your init.d directory, something along the lines of this:

ln -s /usr/local/bin/git-daemon2 git-daemon2

With ubuntu, you can run update-rc.d to ensure that the git-daemon2 script gets launched at startup: