git для пользователей CVS (Git for CVS users)
Имя (Name)
gitcvs-migration - Git for CVS users
Синопсис (Synopsis)
git cvsimport *
Описание (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.
Смотри также (See also)
gittutorial(7), gittutorial-2(7), gitcore-tutorial(7),
gitglossary(7), giteveryday(7), The Git User's Manual
[2]
Примечание (Note)
1. Controlling access to branches using update hooks
file:///usr/local/share/doc/git/howto/update-hook-example.html
2. The Git User's Manual
file:///usr/local/share/doc/git/user-manual.html