Import part of a SVN repository into an existing Git repo

Question

I have an existing SVN repo and I would like to import a part of it, with history into an existing Git repo. Could anyone give me a high-level overview of the commands needed to do this?

Summary:

• I want to move some subdirectories in an existing SVN repository (but not the rest of the repo)
• I have an existing Git repo that I want to import those directories into
• I want to preserve the history of just the subdirectories I moved (but not anything else)

I have a feeling this involves something with git filter-branch and some strange merges. Any help would be appreciated.

Answer 1

It turns out to be pretty complicated, but here's what I did.

1. Prepare the SVN repository first. I was going to delete the files from SVN afterward, so it helped to put all the files in one directory (this also makes filter-branch easier later.)

2. Checked out the SVN repo using git: git svn clone http://path/to/svnrepo. This creates a git version of the svn repo.

3. Using the ideas from this SO post, Detach (move) subdirectory into separate Git repository, I used the filter-branch --subdirectory-filter to filter the directory that I wanted, and to remove history of other stuff from SVN that I did not want to keep in git. You can also use git subtree, a new feature, as in Howto extract a git subdirectory and make a submodule out of it?

4. Then, using the ideas from this SO post, How do you merge two Git repositories?, I imported the new git repo into the parent project that I wanted to add it to. The accepted answer is incorrect, check out the other answers on that page; you want to do a git remote add git-proj <path> followed by a git pull.

5. Finally, push the changes to the git project.