Subversion to Git Migration
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This document discusses migrating a code repository from SVN to Git. It describes using the git-svn tool but finding it slow and not handling branches well for a large codebase. The svn-all-fast-export tool was faster and easier to configure, mapping branches and tags from SVN to Git. Some issues arose like branch amnesia and wrong revisions, but were addressed by patching or rebranching. The document also discusses adopting a Gitflow branching model and benefits of Git like speed, remote work, and a more powerful command line.
![svn-all-fast-export
# rulesmap
create repository bigcommerce
end repository
match /trunk/
repository bigcommerce
branch master
end match
...
match /branches/([^/]+)/
repository bigcommerce
branch 1
end match
...
match /tags/7.3.23/
repository bigcommerce
branch refs/tags/7.3.23
annotated true
end match](https://image.slidesharecdn.com/svn2git-120503051046-phpapp02/85/Subversion-to-Git-Migration-6-320.jpg)
Subversion to Git Migration
- 1. SVN to Git Migration
- 2. Technology ➔ Gitolite. ➔ Atlassian Suite. ➔ Internal system ”Octopus”.
- 4. git-svn ➔ Slow... ➔ Didn't handle shallow merges well. ➔ Our old branches didn't map well. ➔ Works fine for small repos. ➔ Not right for our repo.
- 5. svn-all-fast-export ➔ Faster. ➔ Direct access to git from C libs. ➔ Easier to configure.
- 6. svn-all-fast-export # rulesmap create repository bigcommerce end repository match /trunk/ repository bigcommerce branch master end match ... match /branches/([^/]+)/ repository bigcommerce branch 1 end match ... match /tags/7.3.23/ repository bigcommerce branch refs/tags/7.3.23 annotated true end match
- 8. svn-all-fast-export ➔ Problem: Post migration branch amnesia. Only affected some branches. ➔ Solution(s): Patch from the original svn branch. Rebranch in git, resolve lots of conflicts and pay close attention!
- 9. svn-all-fast-export ➔ Problem: Wrong revision used to create a branch on import. ➔ Solution: Fix it in the source & submit a patch! Check & double check...
- 10. How are we using git?
- 11. SVN branching model Tues Mon Tues Mon Stability Feature-Y Feature-X Trunk RC-02 x RC-01 tfi Ho 1.0 1.2 Time
- 12. Gitflow branching model Tues Mon Tues Mon Stability Feature/y Feature/x Develop Release/1.0 Release/1.3 master 1.3 1.0 1.2 1.3 Time
- 13. Rome wasn't built in a day...
- 14. Identified issues ➔ svn:ignore. Create .gitignore ➔ Empty directories. Fill with .empty files ➔ Commit hooks. Use gitty for hook management.
- 15. Unidentified problems ➔ ”Time & tide waits for no man”. We were fixing the deployment system ”Octopus” on the day. Last minute cherry-picks to tags/branches to get them working.
- 16. Why did we do it? ”...what if anything is ”I miss my git blocking us from switching to git for staging area already” source control?” ”Maybe we should ”f**k; I keep evaluate git more” typing git status”
- 17. Immediate Benefits ➔ Decentralised, remote work. ➔ Much, much faster. ➔ Staged commits, stashes. ➔ Flexible & powerful cmd line.
- 18. Questions?