MIRRORING-PORTS(7) OpenBSD Reference Manual MIRRORING-PORTS(7)NAME
mirroring-ports - how to build a mirror for ports distfiles
DESCRIPTION
The OpenBSD Ports Collection offers some powerful tools to mirror
software sources. The ports infrastructure provides a mirror-maker
target that can be used to build a Makefile to facilitate mirroring
distfiles. This target builds ${DISTDIR}/Makefile, which can be used on
almost any Unix-like machine to mirror OpenBSD distfiles. Optionally,
port dependencies may also be recorded in the Makefile, which greatly
increases the execution time of mirror-maker. The variable
RECURSIVE_FETCH_LIST can be set to `Yes' to request that this is done.
A sample Makefile entry is formatted like this:
all:: audio/tracker/tracker-5.3
.PHONY: audio/tracker/tracker-5.3
audio/tracker/tracker-5.3: tracker-5.3.tgz
tracker-5.3.tgz: $F
@MAINTAINER="espie@openbsd.org" \
SITES="ftp://ftp.uni-trier.de/pub/unix/audio/tracker/ " \
CIPHER="sha1" CKSUM="b0973d6a9c363caebd3a71547412f42b0681f323" \
exec ${FETCH} "$@"
This Makefile is usually invoked by the user from the directory where
they wish to mirror distfiles, with variables FETCH and F set on the
command line, e.g.,
cd mirror && make -k -j 5 -f path_to_makefile FETCH=fetch_script
Targets are set up so that each port is referenced by its full name, and
retrieves all its distfiles. The all target can be used to retrieve all
distfiles. Targets ftp and cdrom can be used to retrieve all distfiles
necessary to build ftp and CD-ROM packages, respectively. Default is ftp
plus cdrom. Actual fetching is usually invoked with a parallel-make
option, so that several retrievals through ftp can proceed
simultaneously.
The F variable can be set to a dummy name, or a recent filename, to force
re-fetching of anything which is older than the filename. Its intended
use is to force re-fetching existing files, or to checksum all files.
The ${FETCH} script should be supplied by the user, and will download and
verify the archive file. It must obey the following variables:
MAINTAINER Port maintainer, used to report errors,
ERROR Some ports problems can be detected while building the
Makefile, in which case this variable will be set to a
proper error message.
DIST_SUBDIR See ports(7) for more details. The ${FETCH} script is
responsible for creating this subdirectory and cd'ing to it
before performing the actual fetch.
SITES A list of sites to try for fetching the distribution file.
CIPHER The checksumming utility to use for verifying the
distribution file. It will normally be set to sha1(1)
unless you tinker with PREFERRED_CIPHER while building the
mirroring Makefile.
CKSUM The corresponding checksum. If neither CIPHER nor CKSUM nor
ERROR are set, the distribution file needs not be checked.
A standard fetch strategy is to try all sites in order: whenever the
distribution file is found, download it; verify the checksum; erase the
file and try the next site if it doesn't match.
Mirroring sites should update their master Makefile fairly often.
Activities a proper mirror should offer (in order of decreasing
importance):
Mirror new files
Use a proper fetch script to download missing files,
Run ${PORTSDIR}/infrastructure/fetch/link-checksums
This script creates permanent hardlinks that preserve
distfiles against checksum changes.
Verify all checksums
All checksums should be verified from time to time, and
maintainers notified of persistent discrepancies,
Check mastersites liveliness
Use a tool such as `mirror' to check that the master sites
haven't fallen off the Earth. Even though the first site in
the site list is the most important site, good mirrors will
scan all sites and report all problems,
Remove old files
To gain room this, the mirror should maintain a list of
`active' files (easy enough, just provide a fetch script that
just lists the file names), and remove files that are no
longer active. Since OpenBSD releases happen every six
months, this delay should be longer than that.
Sample scripts are provided in the ${PORTSDIR}/infrastructure/fetch
directory.
FILES
${DISTDIR}/Makefile
Main mirroring Makefile
${PORTSDIR}/infrastructure/fetch/fetch-all
Sample script usable to retrieve distfiles.
${PORTSDIR}/infrastructure/fetch/check-all
Sample script to check all distfiles checksums.
${PORTSDIR}/infrastructure/fetch/link-checksums
Populating checksums subdirectories with links, to guard
against shifting checksums.
SEE ALSOports(7)HISTORY
This infrastructure was introduced for OpenBSD 2.7 by Marc Espie, with
feedback from Bob Beck, Todd Fries, Camiel Dobbelaar, and a few other
people.
CAVEATS
Changing checksums is a recurring problem that is outside the direct
control of the OpenBSD Project. Some software distributors change
distribution files without warning, without changing the file name
proper. Once the problem has been identified, the port maintainer should
usually contact the software author to fix the problem, or, if the
software author is unresponsive, the maintainer should use DIST_SUBDIR to
provide some state to guard against shifting checksums.
However, a more robust approach is also needed, so that ports users can
depend on distfiles mirrors to carry what they need irrespective of those
synchronization issues. The link-checksums script creates another access
to the distfiles, indexed through the actual checksums that the files
should match. Provided mirroring is run sufficiently often, together
with link-checksums, two versions of the same distfile with respective
checksums cksum1 and cksum2 will be available under the names
${DISTFILES}/sha1/cksum1/distfile and ${DISTFILES}/sha1/cksum2/distfile.
Starting revision 1.281, if REFETCH is set to true, bsd.port.mk will try
to retrieve files under that naming scheme as a last resort.
OpenBSD 4.9 March 26, 2010 OpenBSD 4.9
