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GIT-CVSSERVER(1)		  Git Manual		      GIT-CVSSERVER(1)



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
       o   CVS 1.12.9 on Debian

       o   CVS 1.11.17 on MacOSX (from Fink package)

       o   Eclipse 3.0, 3.1.2 on MacOSX (see Eclipse CVS Client Notes)

       o   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 2.14.4			  06/05/2018		      GIT-CVSSERVER(1)