CVSup is a software package for distributing and updating source trees from a master CVS repository on a remote server host. The FreeBSD sources are maintained in a CVS repository on a central development machine in California. With CVSup, FreeBSD users can easily keep their own source trees up to date.
CVSup uses the so-called
pull model of updating. Under the pull
model, each client asks the server for updates, if and when they
are wanted. The server waits passively for update requests from
its clients. Thus all updates are instigated by the client.
The server never sends unsolicited updates. Users must either
run the CVSup client manually to get
an update, or they must set up a cron job to
run it automatically on a regular basis.
The term CVSup, capitalized just
so, refers to the entire software package. Its main components
are the client cvsup which runs on each
user's machine, and the server cvsupd which
runs at each of the FreeBSD mirror sites.
As you read the FreeBSD documentation and mailing lists, you
may see references to sup.
Sup was the predecessor of
CVSup, and it served a similar
purpose. CVSup is used much in the
same way as sup and, in fact, uses configuration files which are
backward-compatible with sup's.
Sup is no longer used in the FreeBSD
project, because CVSup is both faster
and more flexible.
The easiest way to install CVSup is to use the precompiled net/cvsup package from the FreeBSD packages collection. If you prefer to build CVSup from source, you can use the net/cvsup port instead. But be forewarned: the net/cvsup port depends on the Modula-3 system, which takes a substantial amount of time and disk space to download and build.
If you are going to be using CVSup on a machine which will not have XFree86™ or Xorg installed, such as a server, be sure to use the port which does not include the CVSup GUI, net/cvsup-without-gui.
CVSup's operation is controlled
by a configuration file called the supfile.
There are some sample supfiles in the
directory /usr/share/examples/cvsup/.
The information in a supfile answers
the following questions for CVSup:
In the following sections, we will construct a typical
supfile by answering each of these
questions in turn. First, we describe the overall structure of
a supfile.
A supfile is a text file. Comments
begin with # and extend to the end of the
line. Lines that are blank and lines that contain only
comments are ignored.
Each remaining line describes a set of files that the user
wishes to receive. The line begins with the name of a
“collection”, a logical grouping of files defined by
the server. The name of the collection tells the server which
files you want. After the collection name come zero or more
fields, separated by white space. These fields answer the
questions listed above. There are two types of fields: flag
fields and value fields. A flag field consists of a keyword
standing alone, e.g., delete or
compress. A value field also begins with a
keyword, but the keyword is followed without intervening white
space by = and a second word. For example,
release=cvs is a value field.
A supfile typically specifies more than
one collection to receive. One way to structure a
supfile is to specify all of the relevant
fields explicitly for each collection. However, that tends to
make the supfile lines quite long, and it
is inconvenient because most fields are the same for all of the
collections in a supfile.
CVSup provides a defaulting mechanism
to avoid these problems. Lines beginning with the special
pseudo-collection name *default can be used
to set flags and values which will be used as defaults for the
subsequent collections in the supfile. A
default value can be overridden for an individual collection, by
specifying a different value with the collection itself.
Defaults can also be changed or augmented in mid-supfile by
additional *default lines.
With this background, we will now proceed to construct a
supfile for receiving and updating the main
source tree of FreeBSD-CURRENT.
Which files do you want to receive?
The files available via CVSup
are organized into named groups called
“collections”. The collections that are
available are described in the following section. In this
example, we
wish to receive the entire main source tree for the FreeBSD
system. There is a single large collection
src-all which will give us all of that.
As a first step toward constructing our
supfile, we
simply list the collections, one per line (in this case,
only one line):
src-all
Which version(s) of them do you want?
With CVSup, you can receive
virtually any version of the sources that ever existed.
That is possible because the
cvsupd server works directly from
the CVS repository, which contains all of the versions. You
specify which one of them you want using the
tag= and date= value
fields.
Be very careful to specify any tag=
fields correctly. Some tags are valid only for certain
collections of files. If you specify an incorrect or
misspelled tag, CVSup
will delete files which you probably
do not want deleted. In particular, use only
tag=. for the
ports-* collections.
The tag= field names a symbolic tag
in the repository. There are two kinds of tags, revision
tags and branch tags. A revision tag refers to a specific
revision. Its meaning stays the same from day to day. A
branch tag, on the other hand, refers to the latest revision
on a given line of development, at any given time. Because
a branch tag does not refer to a specific revision, it may
mean something different tomorrow than it means
today.
節 A.7, “CVS Tags” contains branch tags that
users might be interested in. When specifying a tag in
CVSup's configuration file, it
must be preceded with tag=
(RELENG_4 will become
tag=RELENG_4).
Keep in mind that only the tag=. is
relevant for the Ports Collection.
Be very careful to type the tag name exactly as shown. CVSup cannot distinguish between valid and invalid tags. If you misspell the tag, CVSup will behave as though you had specified a valid tag which happens to refer to no files at all. It will delete your existing sources in that case.
When you specify a branch tag, you normally receive the
latest versions of the files on that line of development.
If you wish to receive some past version, you can do so by
specifying a date with the date= value
field. The cvsup(1) manual page explains how to do
that.
For our example, we wish to receive FreeBSD-CURRENT. We
add this line at the beginning of our
supfile:
*default tag=.
There is an important special case that comes into play
if you specify neither a tag= field nor a
date= field. In that case, you receive
the actual RCS files directly from the server's CVS
repository, rather than receiving a particular version.
Developers generally prefer this mode of operation. By
maintaining a copy of the repository itself on their
systems, they gain the ability to browse the revision
histories and examine past versions of files. This gain is
achieved at a large cost in terms of disk space,
however.
Where do you want to get them from?
We use the host= field to tell
cvsup where to obtain its updates. Any
of the CVSup mirror
sites will do, though you should try to select one
that is close to you in cyberspace. In this example we will
use a fictional FreeBSD distribution site,
cvsup99.FreeBSD.org:
*default host=cvsup99.FreeBSD.org
You will need to change the host to one that actually
exists before running CVSup.
On any particular run of
cvsup, you can override the host setting
on the command line, with -h
.hostname
Where do you want to put them on your own machine?
The prefix= field tells
cvsup where to put the files it receives.
In this example, we will put the source files directly into
our main source tree, /usr/src. The
src directory is already implicit in
the collections we have chosen to receive, so this is the
correct specification:
*default prefix=/usr
Where should
cvsup maintain its status files?
The CVSup client maintains
certain status files in what
is called the “base” directory. These files
help CVSup to work more
efficiently, by keeping track of which updates you have
already received. We will use the standard base directory,
/var/db:
*default base=/var/db
If your base directory does not already exist, now would
be a good time to create it. The cvsup
client will refuse to run if the base directory does not
exist.
Miscellaneous supfile
settings:
There is one more line of boiler plate that normally
needs to be present in the
supfile:
*default release=cvs delete use-rel-suffix compress
release=cvs indicates that the server
should get its information out of the main FreeBSD CVS
repository. This is virtually always the case, but there
are other possibilities which are beyond the scope of this
discussion.
delete gives
CVSup permission to delete files.
You should always specify this, so that
CVSup can keep your source tree
fully up-to-date. CVSup is
careful to delete only those files for which it is
responsible. Any extra files you happen to have will be
left strictly alone.
use-rel-suffix is ... arcane. If you
really want to know about it, see the cvsup(1) manual
page. Otherwise, just specify it and do not worry about
it.
compress enables the use of
gzip-style compression on the communication channel. If
your network link is T1 speed or faster, you probably should
not use compression. Otherwise, it helps
substantially.
Putting it all together:
Here is the entire supfile for our
example:
*default tag=. *default host=cvsup99.FreeBSD.org *default prefix=/usr *default base=/var/db *default release=cvs delete use-rel-suffix compress src-all
As mentioned above, CVSup uses
a pull method. Basically, this means that
you connect to the CVSup server, and
it says, “Here is what you can download from
me...”, and your client responds “OK, I will take
this, this, this, and this.” In the default
configuration, the CVSup client will
take every file associated with the collection and tag you
chose in the configuration file. However, this is not always
what you want, especially if you are synching the doc, ports, or
www trees —— most people cannot read four or five
languages, and therefore they do not need to download the
language-specific files. If you are
CVSuping the Ports Collection, you
can get around this by specifying each collection individually
(e.g., ports-astrology,
ports-biology, etc instead of simply
saying ports-all). However, since the doc
and www trees do not have language-specific collections, you
must use one of CVSup's many nifty
features: the refuse file.
The refuse file essentially tells
CVSup that it should not take every
single file from a collection; in other words, it tells the
client to refuse certain files from the
server. The refuse file can be found (or, if you do not yet
have one, should be placed) in
base/sup/.
base is defined in your supfile;
our defined base is
/var/db,
which means that by default the refuse file is
/var/db/sup/refuse.
The refuse file has a very simple format; it simply
contains the names of files or directories that you do not wish
to download. For example, if you cannot speak any languages other
than English and some German, and you do not feel the need to read
the German translation of documentation, you can put the following in your
refuse file:
doc/bn_* doc/da_* doc/de_* doc/el_* doc/es_* doc/fr_* doc/it_* doc/ja_* doc/nl_* doc/no_* doc/pl_* doc/pt_* doc/ru_* doc/sr_* doc/tr_* doc/zh_*
and so forth for the other languages (you can find the full list by browsing the FreeBSD CVS repository).
With this very useful feature, those users who are on
slow links or pay by the minute for their Internet connection
will be able to save valuable time as they will no longer need
to download files that they will never use. For more
information on refuse files and other neat
features of CVSup, please view its
manual page.
You are now ready to try an update. The command line for doing this is quite simple:
#cvsup supfile
where supfile
is of course the name of the supfile you have just created.
Assuming you are running under X11, cvsup
will display a GUI window with some buttons to do the usual
things. Press the button, and watch it
run.
Since you are updating your actual
/usr/src tree in this example, you will
need to run the program as root so that
cvsup has the permissions it needs to update
your files. Having just created your configuration file, and
having never used this program before, that might
understandably make you nervous. There is an easy way to do a
trial run without touching your precious files. Just create an
empty directory somewhere convenient, and name it as an extra
argument on the command line:
#mkdir /var/tmp/dest#cvsup supfile /var/tmp/dest
The directory you specify will be used as the destination
directory for all file updates.
CVSup will examine your usual files
in /usr/src, but it will not modify or
delete any of them. Any file updates will instead land in
/var/tmp/dest/usr/src.
CVSup will also leave its base
directory status files untouched when run this way. The new
versions of those files will be written into the specified
directory. As long as you have read access to
/usr/src, you do not even need to be
root to perform this kind of trial run.
If you are not running X11 or if you just do not like GUIs,
you should add a couple of options to the command line when you
run cvsup:
#cvsup -g -L 2 supfile
The -g tells
CVSup not to use its GUI. This is
automatic if you are not running X11, but otherwise you have to
specify it.
The -L 2 tells
CVSup to print out the
details of all the file updates it is doing. There are three
levels of verbosity, from -L 0 to
-L 2. The default is 0, which means total
silence except for error messages.
There are plenty of other options available. For a brief
list of them, type cvsup -H. For more
detailed descriptions, see the manual page.
Once you are satisfied with the way updates are working, you can arrange for regular runs of CVSup using cron(8). Obviously, you should not let CVSup use its GUI when running it from cron(8).
The file collections available via CVSup are organized hierarchically. There are a few large collections, and they are divided into smaller sub-collections. Receiving a large collection is equivalent to receiving each of its sub-collections. The hierarchical relationships among collections are reflected by the use of indentation in the list below.
The most commonly used collections are
src-all, and
ports-all. The other collections are used
only by small groups of people for specialized purposes, and
some mirror sites may not carry all of them.
cvs-all release=cvsThe main FreeBSD CVS repository, including the cryptography code.
distrib release=cvsFiles related to the distribution and mirroring of FreeBSD.
doc-all release=cvsSources for the FreeBSD Handbook and other documentation. This does not include files for the FreeBSD web site.
ports-all release=cvsThe FreeBSD Ports Collection.
If you do not want to update the whole of
ports-all (the whole ports tree),
but use one of the subcollections listed below,
make sure that you always update
the ports-base subcollection!
Whenever something changes in the ports build
infrastructure represented by
ports-base, it is virtually certain
that those changes will be used by “real”
ports real soon. Thus, if you only update the
“real” ports and they use some of the new
features, there is a very high chance that their build
will fail with some mysterious error message. The
very first thing to do in this
case is to make sure that your
ports-base subcollection is up to
date.
If you are going to be building your own local
copy of ports/INDEX, you
must accept
ports-all (the whole ports tree).
Building ports/INDEX with
a partial tree is not supported. See the
FAQ.
ports-accessibility
release=cvsSoftware to help disabled users.
ports-arabic
release=cvsArabic language support.
ports-archivers
release=cvsArchiving tools.
ports-astro
release=cvsAstronomical ports.
ports-audio
release=cvsSound support.
ports-base
release=cvsThe Ports Collection build infrastructure -
various files located in the
Mk/ and
Tools/ subdirectories of
/usr/ports.
Please see the important warning above: you should always update this subcollection, whenever you update any part of the FreeBSD Ports Collection!
ports-benchmarks
release=cvsBenchmarks.
ports-biology
release=cvsBiology.
ports-cad
release=cvsComputer aided design tools.
ports-chinese
release=cvsChinese language support.
ports-comms
release=cvsCommunication software.
ports-converters
release=cvscharacter code converters.
ports-databases
release=cvsDatabases.
ports-deskutils
release=cvsThings that used to be on the desktop before computers were invented.
ports-devel
release=cvsDevelopment utilities.
ports-dns
release=cvsDNS related software.
ports-editors
release=cvsEditors.
ports-emulators
release=cvsEmulators for other operating systems.
ports-finance
release=cvsMonetary, financial and related applications.
ports-ftp
release=cvsFTP client and server utilities.
ports-games
release=cvsGames.
ports-german
release=cvsGerman language support.
ports-graphics
release=cvsGraphics utilities.
ports-hebrew
release=cvsHebrew language support.
ports-hungarian
release=cvsHungarian language support.
ports-irc
release=cvsInternet Relay Chat utilities.
ports-japanese
release=cvsJapanese language support.
ports-java
release=cvsJava™ utilities.
ports-korean
release=cvsKorean language support.
ports-lang
release=cvsProgramming languages.
ports-mail
release=cvsMail software.
ports-math
release=cvsNumerical computation software.
ports-mbone
release=cvsMBone applications.
ports-misc
release=cvsMiscellaneous utilities.
ports-multimedia
release=cvsMultimedia software.
ports-net
release=cvsNetworking software.
ports-net-im
release=cvsInstant messaging software.
ports-net-mgmt
release=cvsNetwork management software.
ports-net-p2p
release=cvsPeer to peer networking.
ports-news
release=cvsUSENET news software.
ports-palm
release=cvsSoftware support for Palm™ series.
ports-polish
release=cvsPolish language support.
ports-portuguese
release=cvsPortuguese language support.
ports-print
release=cvsPrinting software.
ports-russian
release=cvsRussian language support.
ports-science
release=cvsScience.
ports-security
release=cvsSecurity utilities.
ports-shells
release=cvsCommand line shells.
ports-sysutils
release=cvsSystem utilities.
ports-textproc
release=cvstext processing utilities (does not include desktop publishing).
ports-ukrainian
release=cvsUkrainian language support.
ports-vietnamese
release=cvsVietnamese language support.
ports-www
release=cvsSoftware related to the World Wide Web.
ports-x11
release=cvsPorts to support the X window system.
ports-x11-clocks
release=cvsX11 clocks.
ports-x11-fm
release=cvsX11 file managers.
ports-x11-fonts
release=cvsX11 fonts and font utilities.
ports-x11-toolkits
release=cvsX11 toolkits.
ports-x11-servers
release=cvsX11 servers.
ports-x11-themes
release=cvsX11 themes.
ports-x11-wm
release=cvsX11 window managers.
projects-all release=cvsSources for the FreeBSD projects repository.
src-all release=cvsThe main FreeBSD sources, including the cryptography code.
src-base
release=cvsMiscellaneous files at the top of
/usr/src.
src-bin
release=cvsUser utilities that may be needed in
single-user mode
(/usr/src/bin).
src-contrib
release=cvsUtilities and libraries from outside the
FreeBSD project, used relatively unmodified
(/usr/src/contrib).
src-crypto release=cvsCryptography utilities and libraries from
outside the FreeBSD project, used relatively
unmodified
(/usr/src/crypto).
src-eBones release=cvsKerberos and DES
(/usr/src/eBones). Not
used in current releases of FreeBSD.
src-etc
release=cvsSystem configuration files
(/usr/src/etc).
src-games
release=cvsGames
(/usr/src/games).
src-gnu
release=cvsUtilities covered by the GNU Public
License (/usr/src/gnu).
src-include
release=cvsHeader files
(/usr/src/include).
src-kerberos5
release=cvsKerberos5 security package
(/usr/src/kerberos5).
src-kerberosIV
release=cvsKerberosIV security package
(/usr/src/kerberosIV).
src-lib
release=cvsLibraries
(/usr/src/lib).
src-libexec
release=cvsSystem programs normally executed by other
programs
(/usr/src/libexec).
src-release
release=cvsFiles required to produce a FreeBSD
release
(/usr/src/release).
src-sbin release=cvsSystem utilities for single-user mode
(/usr/src/sbin).
src-secure
release=cvsCryptographic libraries and commands
(/usr/src/secure).
src-share
release=cvsFiles that can be shared across multiple
systems
(/usr/src/share).
src-sys
release=cvsThe kernel
(/usr/src/sys).
src-sys-crypto
release=cvsKernel cryptography code
(/usr/src/sys/crypto).
src-tools
release=cvsVarious tools for the maintenance of
FreeBSD
(/usr/src/tools).
src-usrbin
release=cvsUser utilities
(/usr/src/usr.bin).
src-usrsbin
release=cvsSystem utilities
(/usr/src/usr.sbin).
www release=cvsThe sources for the FreeBSD WWW site.
distrib release=selfThe CVSup server's own configuration files. Used by CVSup mirror sites.
gnats release=currentThe GNATS bug-tracking database.
mail-archive release=currentFreeBSD mailing list archive.
www release=currentThe pre-processed FreeBSD WWW site files (not the source files). Used by WWW mirror sites.
For the CVSup FAQ and other information about CVSup, see The CVSup Home Page.
Most FreeBSD-related discussion of CVSup takes place on the FreeBSD technical discussions 郵遞論壇. New versions of the software are announced there, as well as on the FreeBSD announcements 郵遞論壇.
Questions and bug reports should be addressed to the author
of the program at <cvsup-bugs@polstra.com>.
CVSup servers for FreeBSD are running at the following sites:
(as of UTC)
All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/
Questions that are not answered by the
documentation may be
sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.