From SVN to GIT

First of all, we need to generate SSH keys for our machine:

Generate new SSH keys :

'~' refers to your "home directory".
In Windows, you can find this by opening a command shell (cmd) and typing :

 echo %USERPROFILE%

Before continuing, check your ~/.ssh folder (for example, /home/jamal/.ssh or C:\Users\jamal\.ssh) and look for the following files (existing SSH keys):
  • id_rsa 
  • id_rsa.pub 
if they are not exist, lets create new keys:

$ ssh-keygen -C "[email protected]"

To remove the passphrase for the SSH key without having to create a new key (NOT recommended) :

 $ ssh-keygen -p

This will then prompt you to enter the keyfile location, the old passphrase, and the new passphrase (which can be left blank to have no passphrase). If you would like to do it all on one line without prompts do :

 $ ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile]

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Make sure to change TortoiseGit SSH client to use Git SSH :

Right Click : TortoiseGit -> settings-> network -> SSH Client , set the value to : C:\Program Files\Git\usr\bin\ssh.exe 

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Using Git Bash and to save the password for your SSH private key:

Create ~/.bashrc , to create the bashrc file in windows: (ignore the error)

   copy > ~/.bashrc

Add the following lines to it :

   eval $(ssh-agent)
   ssh-add

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Convert SVN repository to GIT : 

Create a users file (i.e. users.txt) for mapping SVN users to Git it will be something like:

 user1 = First Last Name 
 user2 = First Last Name 
 ...

You can use this one-liner to build a template from your existing SVN repository (run it in Git Bash):

 svn log -q | awk -F '|' '/^r/ {sub("^ ", "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' | sort -u > users.txt

Now pull the SVN data from the repository:

 git svn clone --stdlayout --no-metadata --authors-file=users.txt svn://hostname/path dest_dir-tmp 

This command will create a new Git repository in dest_dir-tmp and start pulling the SVN repository. Note that the "--stdlayout" flag implies you have the common "trunk/, branches/, tags/" SVN layout.

If your layout differs, become familiar with --tags, --branches, --trunk options (in general git svn help).

All common protocols are allowed: svn://, http://, https://. The URL should target the base repository, something like http://svn.mycompany.com/myrepo/repository.

That must not include /trunk, /tag or /branches.

Note that after executing this command it very often looks like the operation is "hanging/freezed", and it's quite normal that it can be stuck for a long time after initializing the new repository. Eventually you will then see log messages which indicates that it's migrating.

Also note that if you omit the --no-metadata flag, Git will append information about the corresponding SVN revision to the commit message (i.e. git-svn-id: svn://svn.mycompany.com/myrepo/@ ) If a user name is not found, update your users.txt file then:


 cd dest_dir-tmp
 git svn fetch

You might have to repeat that last command several times, if you have a large project, until all of the Subversion commits have been fetched:
 
 git svn fetch

When completed, Git will checkout the SVN trunk into a new branch. Any other branches are setup as remotes. You can view the other SVN branches with:
 
 git branch -r

If you want to keep other remote branches in your repository, you want to create a local branch for each one manually. (Skip trunk/master.) If you don't do this, the branches won't get cloned in the final step.
 
 git checkout -b local_branch remote_branch

# It's OK if local_branch and remote_branch are the same name.

Tags are imported as branches. You have to create a local branch, make a tag and delete the branch to have them as tags in Git. To do it with tag "v1":
 
 git checkout -b tag_v1 remotes/tags/v1
 git checkout master
 git tag v1 tag_v1
 git branch -D tag_v1

Clone your GIT-SVN repository into a clean Git repository:
 
 git clone dest_dir-tmp dest_dir
 rm -rf dest_dir-tmp
 cd dest_dir

The local branches that you created earlier from remote branches will only have been copied as remote branches into the new cloned repository. (Skip trunk/master.) For each branch you want to keep:
 
 git checkout -b local_branch origin/remote_branch

Finally, remove the remote from your clean Git repository that points to the now deleted temporary repository:
 git remote rm origin

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To Clone into a BARE Git Repo

 
$ git svn init https://path/to/you/svn repo-git --stdlayout 

#edit  repo-git/.git/config to contain:
[svn-remote "svn"]
        url = https://path/to/you/sv
        fetch = trunk:refs/heads/master
        branches = branches/*:refs/heads/*
        tags = tags/*:refs/tags/*

# also make sure that [ bare = true ]

$ cd repo-git
$ git svn fetch


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Set up an editor to work with GIT on Windows

By executing

 $ git config core.editor notepad

users can now use notepad.exe as their default editor.

or to use Notepadd++ you can create .sh script file with this content

 
#!/bin/sh
"c:/Program Files/Notepad++/notepad++.exe" -multiInst -notabbar -nosession -noPlugin "$*"

and execute
 
$ git config --global core.editor C:/npp.sh

to test that your editor is working
 
$ git config -e


Convert Local Git Repo to shallow
$ git fetch --depth 10

Or

$ git pull --depth 1
$ git gc --prune=all

Or [ good trick for old git versions ]

$ git clone --mirror --depth=5  file://$PWD ../temp
$ rm -rf .git/objects
$ mv ../temp/{shallow,objects} .git
$ rm -rf ../temp

Clean Git Repo
 
$ git reflog expire --all --expire=now
$ git gc --prune=now --aggressive


Sources :
Azure DevOps Services : Use SSH key authentication
https://stackoverflow.com/a/3972103
https://stackoverflow.com/questions/10564/how-can-i-set-up-an-editor-to-work-with-git-on-windows
https://stackoverflow.com/questions/38171899/how-to-reduce-the-depth-of-an-existing-git-clone
https://stackoverflow.com/questions/12544318/why-git-svn-cannot-clone-a-bare-repo

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