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