VTK/Git

VTK version tracking and development will be hosted by Git.

Experimental Repository

We have published an experimental repository on vtk.org. WE REQUEST THAT NO ONE PUBLISH A CLONE OF THIS REPOSITORY AT AN ONLINE HOSTING SITE. This may or may not be the final version of history after conversion from CVS. It may be removed or rewritten at any time. We prefer to not have multiple incompatible histories out there. The final conversion will be available soon, at which point we may all begin sharing changes!

One may browse the repository online using the Gitweb interface at http://vtk.org/vtk-tmp.git.

At the time of this writing the repository does not have branches and tags older than VTK 5.0. Conversion of older branches and tags from CVS will be completed later and added.

Cloning

One may clone the repository using git clone through the native git protocol:

$ git clone git://vtk.org/vtk-tmp.git VTK

or through the (less efficient) http protocol:

$ git clone http://vtk.org/vtk-tmp.git VTK

All further commands work inside the local copy of the repository created by the clone:

$ cd VTK

Branches

At the time of this writing the repository has the following branches:

• master: Development (default)

Submodules

VTK references sample and test data in a submodule called 'VTKData'. These data come in a separate repository because they are much larger than the source tree and are not needed to build. VTKData can be obtained using the git submodule command. First use the 'init' subcommand to register the submodule:

$ git submodule init VTKData

This configures the VTKData submodule to fetch from the default URL git://vtk.org/vtk-data-tmp.git. Next one may optionally configure a different URL, perhaps to use the http protocol:

$ git config submodule.VTKData.url http://vtk.org/vtk-data-tmp.git

Finally, use the 'update' subcommand to get the submodule:

$ git submodule update VTKData

Development

We provide here a brief introduction to development with Git. See the Resources below for further information.

First, use git config to introduce yourself to Git:

$ git config --global user.name "Your Name"
$ git config --global user.email "you@yourdomain.com"

Optionally enable color output from Git commands:

$ git config --global color.ui auto

The --global option stores the configuration settings in ~/.gitconfig in your home directory so that they apply to all repositories.

Publishing

Authorized developers may publish work directly to vtk.org/vtk-tmp.git using Git's SSH protocol.

Note that we may not grant all contributors push access to the vtk.org repository. The distributed nature of Git allows contributors to retain authorship credit even if they do not publish changes directly. After the final conversion to Git is finished we will consider pull requests from online Git hosting sites.

Authentication

All publishers share the git@vtk.org account but each uses a unique ssh key for authentication. If you do not have a public/private ssh key pair, generate one:

$ ssh-keygen -C 'you@yourdomain.com'
Generating public/private rsa key pair.
Enter file in which to save the key ($HOME/.ssh/id_rsa):
Enter passphrase (empty for no passphrase): (use-a-passphrase!!)
Enter same passphrase again: (use-same-passphrase!!)
Your identification has been saved in $HOME/.ssh/id_rsa.
Your public key has been saved in $HOME/.ssh/id_rsa.pub.

To request access, fill out the Kitware Password form. Include your ssh public key, id_rsa.pub, and a reference to someone our administrators may contact to verify your privileges.

Generating an ssh key on Windows

If you are familiar with generating an ssh key on Linux or Mac, you can follow the same procedure on Windows in a "Git Bash" prompt. There is an ssh-keygen program installed with msysGit to help you set up an ssh identity on a Windows machine. By default it puts the ".ssh" directory in the HOME directory, which is typically "/c/Users/Username" on Vista and Windows 7; on XP, it's "/c/Documents and Settings/Username".

Alternatively, you can also set up a "normal" Windows command prompt shell such that it will work with msysGit, without ever invoking the Git Bash prompt if you like. If you install msysGit and accept all its default options, "git" will not be in the PATH. However, if you add "C:\Program Files (x86)\Git\cmd" to your PATH, then only the two commands git and gitk are available to use via *.cmd script wrappers installed by msysGit. Or, if you add "C:\Program Files (x86)\Git\bin" to your PATH, then all of the command line tools that git installs are available.

The full PuTTY suite of tools includes an application called PuTTYgen. If you already have a private key created with PuTTYgen, you may export it to an OpenSSH identity file. Open the key using PuTTYgen and choose "Conversions > Export OpenSSH key" from the menu bar. That will allow you to save an "id_rsa" file for use in the ".ssh" directory. You can also copy and paste the public key portion of the key from the PuTTYgen text field to save into an "id_rsa.pub" file if you like. Or email it to whoever needs the public side of your key pair.

If you routinely set up your own command prompt environment on Windows, using msysGit from that envrionment is a cinch: just add the full path to either Git\cmd or Git\bin to your PATH. (Or, write your own git.cmd wrapper that is in your PATH that simply calls the git.cmd installed with msysGit.) And make sure you have a HOME environment variable that points to the place where the .ssh directory is.

Pushing

Feel free to push anything to the experimental vtk-tmp.git repository. Note however that it is not official and all changes will be thrown away before publishing the official repository.

Git automatically configures a new clone to refer to its origin through a remote called origin. Initially one may fetch or pull changes from origin, but may not push changes to it.

In order to publish new commits in the vtk.org repository, developers must configure a push URL for the origin. Use git config to specify an ssh-protocol URL:

$ git config remote.origin.pushurl git@vtk.org:vtk-tmp.git

(Note that 'pushurl' requires Git >= 1.6.4. Use just 'url' for Git < 1.6.4.)

Once your push URL is configured and your key is installed for git@vtk.org then you can try pushing changes.

Resources

Additional information about Git may be obtained at these sites:

• Git Homepage
• Git Documentation Wiki
• Git Community Book
• Everyday Git
• Git Cheat-Sheet
• Pro Git
• A Visual Git Reference