Git for Victims of Subversion

Initializing new projects

Git	SVN
git init git add . git commit	svnadmin create repo svn import file://repo svn checkout file://repo . or svnadmin create repo svn checkout repo . svn add . svn commit

Browsing repository

Git	SVN
git show rev:file git show rev:directory git show rev	svn cat file svn list directory svn log -rrev url svn diff -crev url

Exporting

Git	SVN
git archive git archive --format=zip HEAD > project.zip	svn export

Basic Commands

Git	SVN
git add file git rm file git mv file	svn add file svn rm file svn mv file

Committing

Git	SVN
git commit -a git commit (without -a) will NOT add all added files!!! Have a look at git commit -a -v	svn commit

Exercise

1. sudo mkdir /rcs
2. sudo chmod 777 /rcs
3. mkdir /rcs/repo
4. cd /rcs/repo
5. echo first line > afile.txt
6. mkdir afolder
7. Initialize repository
8. Add all files to the repository
9. Check whether files have been added
10. Commit the changes
11. Check whether the files have been committed
12. What is the SHA1 of the commit?

Tracking Changes

Git	SVN
git diff git diff rev path git apply git status git show	svn diff | less svn diff -rrev path patch -p0 svn status

Reverting

Git	SVN
git checkout path Removes all local changes!!!	svn revert path

Working with SVN (git svn)

Create SVN repo

mkdir svn; cd svn
svnadmin create ./
svn mkdir file:///rcs/svn/afolder
svn import /etc/passwd file:///rcs/svn/passwod

Check it out with git

mkdir gitsvnwc
git svn clone file:///rcs/svn gitsvnwc/

Updating (git svn)

Pull changes from SVN	Push changes to SVN
Make some changes to the SVN repo svn import /etc/resolv.conf file:///rcs/svn/resolv.conf Update git working copy git svn rebase	echo aline > afile.txt git add afile.txt git commit git svn dcommit svn ls file:///rcs/svn

git svn limitations

• Some of the Git features do not work in SVN
• Do not dcommit Git merge commits to the Subversion repository (i.e., no merging from other branches, just rebasing)
• Do not amend, reorder, or otherwise change commits that have been dcommited to Subversion (same as to the central git repo). Subversion cannot handle modifying or reordering commits.

Exercises

SVN to GIT

1. Server and repos preparations:

## svn part
sudo mkdir /rcs
sudo chmod 777 /rcs
cd /rcs
mkdir svn; cd svn
svnadmin create ./
svn mkdir file:///rcs/svn/trunk
svn mkdir file:///rcs/svn/branches
svn mkdir file:///rcs/svn/tags
svn import ~/slideshow_ file:///rcs/svn/trunk
svn copy file:///rcs/svn/trunk file:///rcs/svn/branches/slbr1 -m "New branch"
svn copy file:///rcs/svn/trunk file:///rcs/svn/tags/v1.0 -m "Tagging first stable version"
# new user-devel
sudo adduser geek
sudo usermod -G osboxes -a geek
su geek
cd

svn checkout file:///rcs/svn/trunk ~/wc1svn
cd ~/wc1svn
echo geek > logo.html
svn ci -m "geek change"
svn st -uv
exit


2. Simple migration without: history, branches and tags

cd
mkdir gitsvnwc
git svn clone file:///rcs/svn gitsvnwc/
cd gitsvnwc
git svn log
git log

rm -Rf .git branches tags
cd trunk
git init
git add .
git commit -m "moved from svn without history, etc"
git clone --bare . ~/repos/newslideshow.git


3. Migration with nicer history and users' credentials

cd
mkdir gitsvnwc1
git svn clone file:///rcs/svn gitsvnwc1/
cd gitsvnwc1
touch users.txt
nano users.txt
####
osboxes = Ms Devel <msdevel@gmail.com>
geek = Geek Geekovsky <gg@gmail.com>
####


cd
svn checkout file:///rcs/svn/trunk ~/wc2svn
cd ~/wc2svn
svn log --xml --quiet | grep author | sort -u | perl -pe 's/.*>(.*?)<.*/$1 = /' > users1.txt
nano users1.txt
...


cd ~/gitsvnwc1
git svn clone file:///rcs/svn/ --authors-file=/home/osboxes/gitsvnwc1/users.txt --no-metadata --prefix "" -s ~/slideshow_nice
cd ~/slideshow_nice
git log
git tag
git branch -a


# migrating tags:
# for t in $(git for-each-ref --format='%(refname:short)' refs/remotes/tags); do git tag ${t/tags\//} $t && git branch -D -r $t; done

# migrating branches:
# for b in $(git for-each-ref --format='%(refname:short)' refs/remotes); do git branch $b refs/remotes/$b && git branch -D -r $b; done

# cleaning:
# git branch -d trunk

# Connecting to new remote git server:
# git clone --bare ~/slideshow ~/repos/slideshowclean.git
# git remote add origin ~/repos/slideshowclean.git

# Pushing to repo
# git push origin --all
# git push origin --tags


4. Working with 'git svn' bridge tool
(https://training-course-material.com/training/Git_for_Victims_of_Subversion)



5. Refusing force-pushes, etc

git config --system receive.denyNonFastForwards true


Workaround for user: delete the branch and then push it back up with the new reference
Solution for admins:

git config --system receive.denyDeletes true



6. Blocking edition of files for specific users, etc
(https://git-scm.com/book/en/v2/Customizing-Git-An-Example-Git-Enforced-Policy)