View source for Git for Victims of Subversion

[[Category:Git|050]]
== Initializing new projects ==
{| class="wikitable" width="400px"
|-
! 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
|}

[[File:Git-ini.png|400px]]

== Browsing repository ==
{| class="wikitable" 
|-
! 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 ==
{| class="wikitable"
|-
! Git !! SVN
|-
|   
 git archive
 git archive --format=zip HEAD > project.zip
|| 
 svn export    
 
|}

== Basic Commands ==
{| class="wikitable" 
|-
! Git !! SVN
|-
| 
 git add file   
 git rm file 
 git mv file
||  
 svn add file   
 svn rm file
 svn mv file
|}


== Committing ==
{| class="wikitable"
|-
! 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          
|}

[[File:Git-commit-a1.png|250px]] [[File:Git-commit-a2.png|250px]]

== Exercise ==
# sudo mkdir /rcs
# sudo chmod 777 /rcs
# mkdir /rcs/repo
# cd /rcs/repo
# echo first line > afile.txt
# mkdir afolder
# Initialize repository
# Add all files to the repository
# Check whether files have been added
# Commit the changes
# Check whether the files have been committed
# What is the SHA1 of the commit?


== Tracking Changes ==
{| class="wikitable"
|-
! 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 ==
{| class="wikitable"
|-
! 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) ==
{| class="wikitable"
|-
! 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 ==

<pre>
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)

</pre>