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.

Resilient

I suspect it might be easier to import the full repository, then use git filter-branch to prune out the stuff you don't want to keep. I'm not sure it's even possible to only import part of an svn repository in that way, and even if you can it's not likely to be simple... – Helvetian

You can dump the Subversion repository using svnadmin dump, and then use svndumpfilter to filter out the parts you don't want. – Hawkshaw

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.

Resilient

worked for me but with git merge --allow-unrelated-histories origin/master to merge the repositories (found from here #1426392) – Averell