NAME

       gitcvs-migration - Git for CVS users

SYNOPSIS

       git cvsimport *

DESCRIPTION

       Git differs from CVS in that every working tree contains a repository with a full copy of
       the project history, and no repository is inherently more important than any other.
       However, you can emulate the CVS model by designating a single shared repository which
       people can synchronize with; this document explains how to do that.

       Some basic familiarity with Git is required. Having gone through gittutorial(7) and
       gitglossary(7) should be sufficient.

DEVELOPING AGAINST A SHARED REPOSITORY

       Suppose a shared repository is set up in /pub/repo.git on the host foo.com. Then as an
       individual committer you can clone the shared repository over ssh with:

           $ git clone foo.com:/pub/repo.git/ my-project
           $ cd my-project

       and hack away. The equivalent of cvs update is

           $ git pull origin

       which merges in any work that others might have done since the clone operation. If there
       are uncommitted changes in your working tree, commit them first before running git pull.

           Note
           The pull command knows where to get updates from because of certain configuration
           variables that were set by the first git clone command; see git config -l and the git-
           config(1) man page for details.

       You can update the shared repository with your changes by first committing your changes,
       and then using the git push command:

           $ git push origin master

       to "push" those commits to the shared repository. If someone else has updated the
       repository more recently, git push, like cvs commit, will complain, in which case you must
       pull any changes before attempting the push again.

       In the git push command above we specify the name of the remote branch to update (master).
       If we leave that out, git push tries to update any branches in the remote repository that
       have the same name as a branch in the local repository. So the last push can be done with
       either of:

           $ git push origin
           $ git push foo.com:/pub/project.git/

       as long as the shared repository does not have any branches other than master.

SETTING UP A SHARED REPOSITORY

       We assume you have already created a Git repository for your project, possibly created
       from scratch or from a tarball (see gittutorial(7)), or imported from an already existing
       CVS repository (see the next section).

       Assume your existing repo is at /home/alice/myproject. Create a new "bare" repository (a
       repository without a working tree) and fetch your project into it:

           $ mkdir /pub/my-repo.git
           $ cd /pub/my-repo.git
           $ git --bare init --shared
           $ git --bare fetch /home/alice/myproject master:master

       Next, give every team member read/write access to this repository. One easy way to do this
       is to give all the team members ssh access to the machine where the repository is hosted.
       If you don’t want to give them a full shell on the machine, there is a restricted shell
       which only allows users to do Git pushes and pulls; see git-shell(1).

       Put all the committers in the same group, and make the repository writable by that group:

           $ chgrp -R $group /pub/my-repo.git

       Make sure committers have a umask of at most 027, so that the directories they create are
       writable and searchable by other group members.

IMPORTING A CVS ARCHIVE

           Note
           These instructions use the git-cvsimport script which ships with git, but other
           importers may provide better results. See the note in git-cvsimport(1) for other
           options.

       First, install version 2.1 or higher of cvsps from https://github.com/andreyvit/cvsps and
       make sure it is in your path. Then cd to a checked out CVS working directory of the
       project you are interested in and run git-cvsimport(1):

           $ git cvsimport -C <destination> <module>

       This puts a Git archive of the named CVS module in the directory <destination>, which will
       be created if necessary.

       The import checks out from CVS every revision of every file. Reportedly cvsimport can
       average some twenty revisions per second, so for a medium-sized project this should not
       take more than a couple of minutes. Larger projects or remote repositories may take
       longer.

       The main trunk is stored in the Git branch named origin, and additional CVS branches are
       stored in Git branches with the same names. The most recent version of the main trunk is
       also left checked out on the master branch, so you can start adding your own changes right
       away.

       The import is incremental, so if you call it again next month it will fetch any CVS
       updates that have been made in the meantime. For this to work, you must not modify the
       imported branches; instead, create new branches for your own changes, and merge in the
       imported branches as necessary.

       If you want a shared repository, you will need to make a bare clone of the imported
       directory, as described above. Then treat the imported directory as another development
       clone for purposes of merging incremental imports.

ADVANCED SHARED REPOSITORY MANAGEMENT

       Git allows you to specify scripts called "hooks" to be run at certain points. You can use
       these, for example, to send all commits to the shared repository to a mailing list. See
       githooks(5).

       You can enforce finer grained permissions using update hooks. See Controlling access to
       branches using update hooks[1].

PROVIDING CVS ACCESS TO A GIT REPOSITORY

       It is also possible to provide true CVS access to a Git repository, so that developers can
       still use CVS; see git-cvsserver(1) for details.

ALTERNATIVE DEVELOPMENT MODELS

       CVS users are accustomed to giving a group of developers commit access to a common
       repository. As we’ve seen, this is also possible with Git. However, the distributed nature
       of Git allows other development models, and you may want to first consider whether one of
       them might be a better fit for your project.

       For example, you can choose a single person to maintain the project’s primary public
       repository. Other developers then clone this repository and each work in their own clone.
       When they have a series of changes that they’re happy with, they ask the maintainer to
       pull from the branch containing the changes. The maintainer reviews their changes and
       pulls them into the primary repository, which other developers pull from as necessary to
       stay coordinated. The Linux kernel and other projects use variants of this model.

       With a small group, developers may just pull changes from each other’s repositories
       without the need for a central maintainer.

SEE ALSO

       gittutorial(7), gittutorial-2(7), gitcore-tutorial(7), gitglossary(7), giteveryday(7), The
       Git User’s Manual[2]

GIT

       Part of the git(1) suite

NOTES

        1. Controlling access to branches using update hooks
           file:///usr/share/doc/git/html/howto/update-hook-example.html

        2. The Git User’s Manual
           file:///usr/share/doc/git/html/user-manual.html