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.Dd $Mdocdate: March 13 2015 $
.Dt MIRRORING-PORTS 7
.Os
.Sh NAME
.Nm mirroring-ports
.Nd how to build a mirror for ports distfiles
.Sh DESCRIPTION
The
.Nm OpenBSD Ports Collection
offers some powerful tools to mirror software sources.
.Pp
.Xr dpb 1
features a
.Fl F
option which is explicitly designed for mirroring distfiles.
.Pp
If run with
.Fl F Ar jobs ,
.Nm dpb
will
.Bl -bullet
.It
Limit itself to fetching distfiles, and not build any packages.
.It
Disregard any architecture or broken annotation, and try to fetch every
distfile.
.It
Fetch files to a temporary copy named
.Pa some_file.part
using
.Ic ftp -C
to resume interrupted downloads.
.It
Keep a global list of sha256 checksums as
.Pa ${DISTDIR}/distinfo ,
and use that to refetch files when the ports tree records a changing checksum.
.It
Produces a log of old distfiles in
.Pa ${DISTDIR}/history ,
.It
Create sha256 links under
.Pa ${DISTDIR}/by_cipher/sha256
as per
.Xr link-checksum 1 Ns 's
former duties.
.El
.Pp
For partial distfiles collections,
.Nm dpb
can also be run with
.Fl D Ns Ar HISTORY_ONLY
to scan the full ports tree and update
.Pa ${DISTDIR}/history
without fetching anything.
.Sh FILES
.Bl -tag -width toto
.It Pa ${DISTDIR}/distinfo
a cache of known distfiles with their respective checksums.
.It Pa ${DISTDIR}/history
List of files appearing in
.Pa ${DISTDIR}/distinfo
that seem to no longer be required by the ports tree.
.Xr dpb 1
will append to this file each time it is run on the whole tree
(option
.Fl a )
and only if the ports tree scan finishes without error.
Each line is of the form
.Bd -literal -offset indent
timestamp SHA256 (file) = sha
.Ed
.Pp
denoting the first fime a file/sha entry was no longer seen in the ports tree.
.El
.Sh SEE ALSO
.Xr clean-old-distfiles 1 ,
.Xr dpb 1 ,
.Xr ports 7
.Sh HISTORY
The new integrated
.Fl F
option to
.Xr dpb 1
was introduced in
.Ox 5.1 ,
replacing the original infrastructure introduced in
.Ox 2.7 .
.Sh CAVEATS
Changing checksums is a recurring problem that is outside the direct
control of the
.Ox
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
.Ev DIST_SUBDIR
to provide some state to guard against shifting checksums.
.Pp
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
.Pa ${DISTFILES}/by-cipher/sha256
directory provides more persistent access to the distfiles,
indexed through the actual checksums that the files should match.
Provided mirroring is run sufficiently often,
two versions of the same distfile with respective checksums cksum1 and cksum2
will be available under the names
.Pa ${DISTFILES}/sha256/c1/cksum1/distfile
and
.Pa ${DISTFILES}/sha256/c2/cksum2/distfile .
.Pp
If
.Ev REFETCH
is set to true,
.Xr bsd.port.mk 5
will try to retrieve files under that naming scheme as a last resort.