Provided by: git-cvs_2.7.4-0ubuntu1.10_all 
NAME
git-cvsserver - A CVS server emulator for Git
SYNOPSIS
SSH:
export CVS_SERVER="git cvsserver"
cvs -d :ext:user@server/path/repo.git co <HEAD_name>
pserver (/etc/inetd.conf):
cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver
Usage:
git-cvsserver [options] [pserver|server] [<directory> ...]
OPTIONS
All these options obviously only make sense if enforced by the server side. They have been implemented to
resemble the git-daemon(1) options as closely as possible.
--base-path <path>
Prepend path to requested CVSROOT
--strict-paths
Don’t allow recursing into subdirectories
--export-all
Don’t check for gitcvs.enabled in config. You also have to specify a list of allowed directories (see
below) if you want to use this option.
-V, --version
Print version information and exit
-h, -H, --help
Print usage information and exit
<directory>
You can specify a list of allowed directories. If no directories are given, all are allowed. This is
an additional restriction, gitcvs access still needs to be enabled by the gitcvs.enabled config
option unless --export-all was given, too.
DESCRIPTION
This application is a CVS emulation layer for Git.
It is highly functional. However, not all methods are implemented, and for those methods that are
implemented, not all switches are implemented.
Testing has been done using both the CLI CVS client, and the Eclipse CVS plugin. Most functionality works
fine with both of these clients.
LIMITATIONS
CVS clients cannot tag, branch or perform Git merges.
git-cvsserver maps Git branches to CVS modules. This is very different from what most CVS users would
expect since in CVS modules usually represent one or more directories.
INSTALLATION
1. If you are going to offer CVS access via pserver, add a line in /etc/inetd.conf like
cvspserver stream tcp nowait nobody git-cvsserver pserver
Note: Some inetd servers let you specify the name of the executable independently of the value of
argv[0] (i.e. the name the program assumes it was executed with). In this case the correct line in
/etc/inetd.conf looks like
cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver
Only anonymous access is provided by pserve by default. To commit you will have to create pserver
accounts, simply add a gitcvs.authdb setting in the config file of the repositories you want the
cvsserver to allow writes to, for example:
[gitcvs]
authdb = /etc/cvsserver/passwd
The format of these files is username followed by the encrypted password, for example:
myuser:$1Oyx5r9mdGZ2
myuser:$1$BA)@$vbnMJMDym7tA32AamXrm./
You can use the htpasswd facility that comes with Apache to make these files, but Apache’s MD5 crypt
method differs from the one used by most C library’s crypt() function, so don’t use the -m option.
Alternatively you can produce the password with perl’s crypt() operator:
perl -e 'my ($user, $pass) = @ARGV; printf "%s:%s\n", $user, crypt($user, $pass)' $USER password
Then provide your password via the pserver method, for example:
cvs -d:pserver:someuser:somepassword <at> server/path/repo.git co <HEAD_name>
No special setup is needed for SSH access, other than having Git tools in the PATH. If you have
clients that do not accept the CVS_SERVER environment variable, you can rename git-cvsserver to cvs.
Note: Newer CVS versions (>= 1.12.11) also support specifying CVS_SERVER directly in CVSROOT like
cvs -d ":ext;CVS_SERVER=git cvsserver:user@server/path/repo.git" co <HEAD_name>
This has the advantage that it will be saved in your CVS/Root files and you don’t need to worry about
always setting the correct environment variable. SSH users restricted to git-shell don’t need to
override the default with CVS_SERVER (and shouldn’t) as git-shell understands cvs to mean
git-cvsserver and pretends that the other end runs the real cvs better.
2. For each repo that you want accessible from CVS you need to edit config in the repo and add the
following section.
[gitcvs]
enabled=1
# optional for debugging
logFile=/path/to/logfile
Note: you need to ensure each user that is going to invoke git-cvsserver has write access to the log
file and to the database (see Database Backend. If you want to offer write access over SSH, the users
of course also need write access to the Git repository itself.
You also need to ensure that each repository is "bare" (without a Git index file) for cvs commit to
work. See gitcvs-migration(7).
All configuration variables can also be overridden for a specific method of access. Valid method
names are "ext" (for SSH access) and "pserver". The following example configuration would disable
pserver access while still allowing access over SSH.
[gitcvs]
enabled=0
[gitcvs "ext"]
enabled=1
3. If you didn’t specify the CVSROOT/CVS_SERVER directly in the checkout command, automatically saving
it in your CVS/Root files, then you need to set them explicitly in your environment. CVSROOT should
be set as per normal, but the directory should point at the appropriate Git repo. As above, for SSH
clients not restricted to git-shell, CVS_SERVER should be set to git-cvsserver.
export CVSROOT=:ext:user@server:/var/git/project.git
export CVS_SERVER="git cvsserver"
4. For SSH clients that will make commits, make sure their server-side .ssh/environment files (or
.bashrc, etc., according to their specific shell) export appropriate values for GIT_AUTHOR_NAME,
GIT_AUTHOR_EMAIL, GIT_COMMITTER_NAME, and GIT_COMMITTER_EMAIL. For SSH clients whose login shell is
bash, .bashrc may be a reasonable alternative.
5. Clients should now be able to check out the project. Use the CVS module name to indicate what Git
head you want to check out. This also sets the name of your newly checked-out directory, unless you
tell it otherwise with -d <dir_name>. For example, this checks out master branch to the
project-master directory:
cvs co -d project-master master
DATABASE BACKEND
git-cvsserver uses one database per Git head (i.e. CVS module) to store information about the repository
to maintain consistent CVS revision numbers. The database needs to be updated (i.e. written to) after
every commit.
If the commit is done directly by using git (as opposed to using git-cvsserver) the update will need to
happen on the next repository access by git-cvsserver, independent of access method and requested
operation.
That means that even if you offer only read access (e.g. by using the pserver method), git-cvsserver
should have write access to the database to work reliably (otherwise you need to make sure that the
database is up-to-date any time git-cvsserver is executed).
By default it uses SQLite databases in the Git directory, named gitcvs.<module_name>.sqlite. Note that
the SQLite backend creates temporary files in the same directory as the database file on write so it
might not be enough to grant the users using git-cvsserver write access to the database file without
granting them write access to the directory, too.
The database can not be reliably regenerated in a consistent form after the branch it is tracking has
changed. Example: For merged branches, git-cvsserver only tracks one branch of development, and after a
git merge an incrementally updated database may track a different branch than a database regenerated from
scratch, causing inconsistent CVS revision numbers. git-cvsserver has no way of knowing which branch it
would have picked if it had been run incrementally pre-merge. So if you have to fully or partially (from
old backup) regenerate the database, you should be suspicious of pre-existing CVS sandboxes.
You can configure the database backend with the following configuration variables:
Configuring database backend
git-cvsserver uses the Perl DBI module. Please also read its documentation if changing these variables,
especially about DBI->connect().
gitcvs.dbName
Database name. The exact meaning depends on the selected database driver, for SQLite this is a
filename. Supports variable substitution (see below). May not contain semicolons (;). Default:
%Ggitcvs.%m.sqlite
gitcvs.dbDriver
Used DBI driver. You can specify any available driver for this here, but it might not work. cvsserver
is tested with DBD::SQLite, reported to work with DBD::Pg, and reported not to work with DBD::mysql.
Please regard this as an experimental feature. May not contain colons (:). Default: SQLite
gitcvs.dbuser
Database user. Only useful if setting dbDriver, since SQLite has no concept of database users.
Supports variable substitution (see below).
gitcvs.dbPass
Database password. Only useful if setting dbDriver, since SQLite has no concept of database
passwords.
gitcvs.dbTableNamePrefix
Database table name prefix. Supports variable substitution (see below). Any non-alphabetic characters
will be replaced with underscores.
All variables can also be set per access method, see above.
Variable substitution
In dbDriver and dbUser you can use the following variables:
%G
Git directory name
%g
Git directory name, where all characters except for alpha-numeric ones, ., and - are replaced
with _ (this should make it easier to use the directory name in a filename if wanted)
%m
CVS module/Git head name
%a
access method (one of "ext" or "pserver")
%u
Name of the user running git-cvsserver. If no name can be determined, the numeric uid is used.
ENVIRONMENT
These variables obviate the need for command-line options in some circumstances, allowing easier
restricted usage through git-shell.
GIT_CVSSERVER_BASE_PATH takes the place of the argument to --base-path.
GIT_CVSSERVER_ROOT specifies a single-directory whitelist. The repository must still be configured to
allow access through git-cvsserver, as described above.
When these environment variables are set, the corresponding command-line arguments may not be used.
ECLIPSE CVS CLIENT NOTES
To get a checkout with the Eclipse CVS client:
1. Select "Create a new project → From CVS checkout"
2. Create a new location. See the notes below for details on how to choose the right protocol.
3. Browse the modules available. It will give you a list of the heads in the repository. You will not be
able to browse the tree from there. Only the heads.
4. Pick HEAD when it asks what branch/tag to check out. Untick the "launch commit wizard" to avoid
committing the .project file.
Protocol notes: If you are using anonymous access via pserver, just select that. Those using SSH access
should choose the ext protocol, and configure ext access on the Preferences→Team→CVS→ExtConnection pane.
Set CVS_SERVER to "git cvsserver". Note that password support is not good when using ext, you will
definitely want to have SSH keys setup.
Alternatively, you can just use the non-standard extssh protocol that Eclipse offer. In that case
CVS_SERVER is ignored, and you will have to replace the cvs utility on the server with git-cvsserver or
manipulate your .bashrc so that calling cvs effectively calls git-cvsserver.
CLIENTS KNOWN TO WORK
• CVS 1.12.9 on Debian
• CVS 1.11.17 on MacOSX (from Fink package)
• Eclipse 3.0, 3.1.2 on MacOSX (see Eclipse CVS Client Notes)
• TortoiseCVS
OPERATIONS SUPPORTED
All the operations required for normal use are supported, including checkout, diff, status, update, log,
add, remove, commit.
Most CVS command arguments that read CVS tags or revision numbers (typically -r) work, and also support
any git refspec (tag, branch, commit ID, etc). However, CVS revision numbers for non-default branches are
not well emulated, and cvs log does not show tags or branches at all. (Non-main-branch CVS revision
numbers superficially resemble CVS revision numbers, but they actually encode a git commit ID directly,
rather than represent the number of revisions since the branch point.)
Note that there are two ways to checkout a particular branch. As described elsewhere on this page, the
"module" parameter of cvs checkout is interpreted as a branch name, and it becomes the main branch. It
remains the main branch for a given sandbox even if you temporarily make another branch sticky with cvs
update -r. Alternatively, the -r argument can indicate some other branch to actually checkout, even
though the module is still the "main" branch. Tradeoffs (as currently implemented): Each new "module"
creates a new database on disk with a history for the given module, and after the database is created,
operations against that main branch are fast. Or alternatively, -r doesn’t take any extra disk space, but
may be significantly slower for many operations, like cvs update.
If you want to refer to a git refspec that has characters that are not allowed by CVS, you have two
options. First, it may just work to supply the git refspec directly to the appropriate CVS -r argument;
some CVS clients don’t seem to do much sanity checking of the argument. Second, if that fails, you can
use a special character escape mechanism that only uses characters that are valid in CVS tags. A sequence
of 4 or 5 characters of the form (underscore ("_"), dash ("-"), one or two characters, and dash ("-"))
can encode various characters based on the one or two letters: "s" for slash ("/"), "p" for period ("."),
"u" for underscore ("_"), or two hexadecimal digits for any byte value at all (typically an ASCII number,
or perhaps a part of a UTF-8 encoded character).
Legacy monitoring operations are not supported (edit, watch and related). Exports and tagging (tags and
branches) are not supported at this stage.
CRLF Line Ending Conversions
By default the server leaves the -k mode blank for all files, which causes the CVS client to treat them
as a text files, subject to end-of-line conversion on some platforms.
You can make the server use the end-of-line conversion attributes to set the -k modes for files by
setting the gitcvs.usecrlfattr config variable. See gitattributes(5) for more information about
end-of-line conversion.
Alternatively, if gitcvs.usecrlfattr config is not enabled or the attributes do not allow automatic
detection for a filename, then the server uses the gitcvs.allBinary config for the default setting. If
gitcvs.allBinary is set, then file not otherwise specified will default to -kb mode. Otherwise the -k
mode is left blank. But if gitcvs.allBinary is set to "guess", then the correct -k mode will be guessed
based on the contents of the file.
For best consistency with cvs, it is probably best to override the defaults by setting gitcvs.usecrlfattr
to true, and gitcvs.allBinary to "guess".
DEPENDENCIES
git-cvsserver depends on DBD::SQLite.
GIT
Part of the git(1) suite
Git 2.7.4 03/04/2021 GIT-CVSSERVER(1)