Note: I wrote this post a long time ago but never got around to posting it. A lot of these steps are applicable to porting an SVN repo to Git as well.

Preface on why I love git

Roughly four years ago I switched to git for version control and it’s changed my development life. While SVN is sufficient to “get the job done” in terms of keeping a history of your commits with a group of people, Git is truly the next evolutionary step up in every way. I could expound a whole article on the joy of git, but many others already have, and this articles not about that. But I will kindly throw in my 0.02 on why I personally love it:

  • It’s fast. Git keeps your whole repo’s history local. So no need to ping your repo server for every command. You can even checkout your codebase from 3 weeks ago or a year ago in under a second.”
  • It works offline. That’s right, no internet. Sync up later.
  • It has useful modern tools. Like git stash and git bisect. Both will save you a lot of time.
  • It’s your third hand. Let’s face it, besides svn being slow, it’s not friendly enough to do more than throw your past commits into an empty hole you will probably never see again. With very little setup, you have beautiful colored output in your logs and diffs with git. And “git log” actually pages by default (while keeping colors) instead of flooding your console with the entire repos history! Want to query something in your history log? What about all commits from your friend Bob in the past 2 weeks?
    git log --date=relative --author=nizam --since="2 weeks ago"

    Bam. Done.

  • Easy repo creation. You don’t have to be an admin to setup a git repo. Just cd into a folder and type “git init”. You just created a new repo. I do this all the time, for example in my folder of todo lists, I use it to track history of my todos. At work someone kept messing up the apache config file, all I had to do was “git init” in /etc/httpd/conf and now I can easily “git diff” new changes that were made and revert / adjust if needed.
  • Many ways to use it. Git is promoted as “decentralized” version control, but it can be an easy drop in replacement for any job SVN can do. Which leads me to…

With all those advantages, many larger companies haven’t jumped on the git bandwagon. I believe there’s two reasons this is the case.

  • As programmers get more experienced, they generally become more pragmatic (which is generally a good thing.) They adopt a “if it ain’t broke, don’t fix it.” mentality. After all, SVN get’s the job done.
  • There is a bit of a learning curve with git. But there are a ton of good resources for learning it. I recommend getting your hands dirty with Git Immersion if you’re new or would like to learn. I don’t recommend wrapping git around svn as I’m about to show you for a person who’s learning git.

Getting down to business.

In order to use git with an svn repo, you’ll have to run some commands to import that svn repo, commit by commit into a git repo.

1. First, make sure you have a version of git installed with svn bindings. If you type “git svn” and it give you an error, I’d google one of the resources in reinstalling git with svn bindings.

2. We need to keep

# In your existing svn repo, lets grab a list of authors
svn log -q | awk -F '|' '/^r/ {sub("^ ", "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' | sort -u > authors.txt
# create a new folder
cd ..; mkdir NEWREPO.git;
git svn clone -A ../OLDREPO/authors.txt https://svn/repo/trunk
git svn fetch # this could take a long time as it checks the repo out one rev at a time.
 
# update your working copy:
git-svn rebase
 
# commit your changes to svn server
git-svn dcommit

kudos to:

http://flavio.castelli.name/howto_use_git_with_svn