Provided by: emdebian-grip-server_3.0.7_all bug

NAME

       Emdebian::Grip - internal Emdebian module for Emdebian Grip repositories

Description

       It is worthwhile being familiar with "reprepro" (1) when working with this module.

       Emdebian::Grip provides repository management support for the em_autogrip scripting to
       manage a three-way repository hierarchy for Emdebian Grip, including support for migrating
       packages from unstable into testing.

       Considering just "unstable" initially, the hierarchy is as follows:

       Debian unstable is filtered using ${base}${filter_name}/conf/pkglist which in turn is
       based on the output of dpkg --get-selections. Only packages that are actually installed on
       machines running Emdebian Grip get added to the pkglist. "reprepro" then updates
       ${filter_name} from the chosen Debian mirror, downloading only the binary and source
       packages specified in pkglist, to create a partial local mirror for the list of supported
       architectures.

       Grip unstable is built from the filtered mirror by a combined process of converting the
       source package and then identifying the missing binary packages from the pkglist. During
       the "emgrip" process, Emdebian TDebs are created which get included into the locale
       repository:

       Locale is a very specialised repository that is designed for Debian source packages and
       Emdebian TDebs only, organised by locale root.  e.g. en_GB support is in the en component.
       Whereas Debian has three components (main, contrib and non-free), the locale repository
       has ninety seven components (including main for the source packages). In the locale pool,
       packages are organised by component so whereas in the filter or grip repository, "apt"
       packages are under pool/main/a/apt in the locale repository the en TDebs for apt are in
       pool/en/a/apt/ and the French under pool/fr/a/apt/ etc. The list of locale roots supported
       by the locale repository is returned by &get_locale_roots, part of the
       "Debian::Packages::Compare" module.  For more information on locale roots as components
       see: <http://www.emdebian.org/emdebian/langupdate.html>

       As far as testing is concerned, the hierarchy works in a similar way to Debian, but with
       extra support for repositories that are started after packages have migrated into Debian
       testing and a newer version exists in Debian unstable.

       Note that the testing repository data needs to be setup manually in many cases - editing
       conf/distributions for each repository. The current Emdebian conf files will find their
       way onto the Debian Wiki in due course.

       With a fully populated Debian unstable, Grip unstable and locale unstable, &grip_britney
       can then migrate packages into Grip testing using the criteria implemented in
       &get_britney_list from "Debian::Packages::Compare" and the "reprepro copysrc" command. As
       most, if not all, Grip repositories will begin at a time when some packages in Debian have
       already migrated into testing and had a newer version uploaded to unstable,
       "Emdebian::Grip" also includes catch-up support via &migrate_missing which includes the
       relevant packages from Debian testing as if that version had been uploaded directly to
       Grip testing (which, in effect, is what is happening).

       The emgrip process can take a significant amount of time - think many hours, not minutes -
       principally due to the overhead of generating the TDebs at one per source per locale per
       architecture.  To create a full unstable and testing set is likely to take a day or more
       but is mostly automated.

       The problems that remain are related to dependency issues. The &edos function in
       "Emdebian::Grip" does have problems trying to calculate the solution for dependency
       problems identified by "edos-debcheck" and the problems become particularly acute if the
       repository itself is not in good shape at the start. Therefore, &edos is not run
       automatically by the current tools. The repository must be fully up to date and all
       relevant packages need to exist in the filter and in Grip before using &edos support.
       Initially, use "edos-debcheck" directly to identify major problems:

        edos-debcheck -explain -failures < ${base}${grip_name}/dists/sid/main/binary-i386/Packages

       Packages that are NOT AVAILABLE need to be gripped as source or binary packages as
       appropriate but care is needed to correctly interpret the "edos-debcheck" output to
       identify the correct link in the chain.

       Two major problems exist with automating this process, see "em_autogrip" (1) for specific
       information, but suffice it to say here that there exist in Debian unstable, packages that
       will appear in the list of NOT AVAILABLE packages where the correct action is to REMOVE
       the package that depends on the unavailable package. These issues are being discussed
       within Debian.

Copyright and Licence

        Copyright (C) 2007-2009  Neil Williams <codehelp@debian.org>

        This package is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 3 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program.  If not, see <http://www.gnu.org/licenses/>.

Example

        use strict;
        use warnings;
        use Emdebian::Grip;
        use Debian::Packages::Compare;

        use vars qw/ $filter_name $grip_name $suite $base $verbose
         $noskip @archlist @locroots @lines $line %pkg @filter $have
         %debianunstable %gripunstable %tdebunstable /;

        my $mirror='http://ftp.uk.debian.org/debian'; # default
        $filter_name = 'filter';
        $grip_name = 'grip';
        $suite = "unstable"; # at first
        $base = '/opt/reprepro/';
        $verbose = 0;

        &set_base($base);
        &set_repo_names ($filter_name, $grip_name);
        my $a = &get_archlist ($suite, $filter_name);
        @archlist = (not defined $a or not @$a) ?
          qw/i386 amd64 arm armel powerpc mips mipsel/ : @$a;
        my $l = &get_locale_roots ($suite, 'locale');
        @locroots = (not defined $l or not @$l) ? qw/ af am ang ar as ast az be bg
         bn br bs ca cs cy da de dz el en eo es et eu fa fi fr ga gl gu he hi hr
         hu hy ia id io is it ja ka kn km ko ku ky lg li lt lv mai mg mi mk ml mn mr
         ms nb ne nl nn no ns nso oc or pa pl ps pt rm ro ru rw si sk sl sq sr sv
         ta te th tk tl tr tt ug uk ur uz vi wa wo xh yi zh zu / : @$l;

        &setup_repos if ( not -f "${base}${filter_name}/conf/pkglist" );

        my $debu  = &read_packages ('unstable', $filter_name);
        my $gripu = &read_packages ('unstable', $grip_name);
        my $tdebu = &read_locale   ('unstable', 'locale');
        %debianunstable = %$debu   if (defined $debu);
        %gripunstable   = %$gripu  if (defined $gripu);
        %tdebunstable   = %$tdebu  if (defined $tdebu);
        &update_filter;
        &update_repo($verbose);

        # begin the work.

set_repo_names

       Copies the default or user-specified filter and grip repository names into the internal
       module.

set_noskip

       Copies the user-specified --noskipold option into the internal module for use when calling
       reprepro.

set_dry_run

       Configures a dry-run where external commands are printed instead of executed.

print_missing

       Outputs the list returned by "Debian::Package::Compare::get_missing_sources" in a simple
       format

print_build_deps

       Outputs the list returned by "Debian::Package::Compare::get_missing_builddeps" in a simple
       format

print_testing_status

       Provides a detailed output of the status of the testing repository for Grip, comparing
       Debian unstable (filter) against Debian testing (filter) and identifying which source
       packages in Emdebian Grip testing are behind Debian.

       This list is further split into those where the source version in Debian unstable is
       precisely the same as the source version in Debian testing (packages that need to be
       migrated into Grip testing) and those where the version in testing differs.

grip_britney

       Grip version of the Britney script that migrates packages into Debian testing. See
       "Debian::Packages::Compare" (3) for details on get_britney_list criteria.

       In addition, in order to allow new repositories to catch up with Debian, packages in Grip
       unstable that are already ahead of Debian testing need to be gripped directly from Debian
       testing.

       This can also happen when packages are put directly into testing using testing-proposed-
       updates during a release freeze in Debian.

       Note that grip_britney only migrates packages where the version in Debian unstable is the
       same as the version in Debian testing - i.e.  where a migration has already taken place in
       Debian. Packages that arrive in testing via testing-proposed-updates or migrated into
       testing before the Grip repository was started and which have a later version now in
       unstable, can be migrated using migrate_missing.

       If you are running grip_britney and migrate_missing together, run grip_britney first and
       reload all the data using read_packages before attempting to run migrate_missing. See
       migrate_missing for more information.

migrate_missing

       Corollary of grip_britney that completes the process by including into testing, packages
       that have a different version in Debian unstable.

       Missing packages in testing are included using grip_source and grip_binary as if uploaded
       directly to testing (which, in effect, is what is happening). This means that
       migrate_missing will take just as long to process the package in testing as it did to
       process the later version that went into unstable. Depending on the number of packages
       affected, migrate_missing can take a lot longer than grip_britney but it should be needed
       less often once the repository is complete.

edos

       Only a basic framework at this stage, this function needs to eventually collate the
       results by architecture and repository and try to present a solution.

       See "em_autogrip" (1) for problems with edos recursion.

       In $mode eq 'edos', simply outputs the check data for each of the filter and grip
       repositories.

clean_incoming

       Call intermittently during long runs.

cleanup

       Only call before exit.

update_filter

       Fill in the FilterList so that automatic updates can proceed - without a filter, the
       entire archive is added. However, updating takes an appreciable amount of time, so call
       only when necessary.

extend_filter

       Adds package(s) to the filter list, a space separated list is acceptable.

update_repo

       Once the pkglist filter file is correct, call reprepro to get updated packages.

incoming_locale

       Checks the incoming directory for Emdebian TDebs and includes them into reprepro.

       Until the .tdeb extension is supported, reprepro needs to be persuaded to allow such files
       using the "--ignore=extension" option.

       Amongst all the expected error messages, some useful output is sent to "STDERR" by
       reprepro when handling TDebs so errors are not redirected to /dev/null.

check_dirs

       Check that critical directories in the three-way repository hierarchy exist and create any
       that are missing.

setup_repos

       Note: When setting up your own repository, remember that including the Contents: specifier
       in reprepro costs a lot of time during each and every operation on the repository.
       Contents is not enabled by "setup_repos" and it is strongly recommended that it is not re-
       enabled in later changes.

       Need to decide whether this will cope with multiple suites or just enforce suite=unstable.

       locale is shared with Crush. It's not particularly easy to add a new locale root as the
       scripts and the repos need to be changed at the same time.

       necessary reprepro data (needs config support): these files need to be created for
       reprepro final repos will also need "SignWith: 0x97BB3B58" except stable which should be
       signed manually to bridge the security gap between Grip and Debian.

convert_prefix

       Debian repositories use the index character of the source package name in the path to the
       package directory beneath the pool in order to reduce the number of listings per directory
       to a manageable level. The exception is source packages beginning with '"lib"', because
       there are so many that the '"l"' section would be too large. Whilst '"l"' remains, any
       source package that begins with '"lib"' is put under a separate set of directories using
       the first four letters instead of just '"l"', e.g. "libaa" will be found under
       "pool/main/liba/libaa/" and "libfoo" under "pool/main/libf/libfoo/" but "limpet" would be
       under "pool/main/l/limpet/"

       convert_prefix is a quick function to determine the correct prefix under these rules.

grip_source

       Wrapper for emgrip that takes a single Debian source package, grips the binary package
       where the source package name matches the binary package name (due to a hitch in how
       "reprepro" works), generates any Emdebian TDebs, includes the unchanged source package
       into Grip, includes any gripped binary packages into Grip and includes any generated
       Emdebian TDebs into locale.

       Once the source package has been processed, runs &clean_incoming.

grip_binary

       Wrapper for emgrip that takes a single Debian binary package, and grips it, generates any
       Emdebian TDebs, includes the gripped binary package into Grip and includes any generated
       Emdebian TDebs into locale.

       Once the binary package has been processed, runs &clean_incoming.

   Components and Sections
       Each binary package belongs to a "Section" that broadly describes the type of
       functionality in the package. If a component exists in the repository with the same name
       as the "Section", the package will be put into that component. Additionally, if the
       package name ends in "-dev" or the "Section" is devel, the "dev" component is selected. If
       the package name ends in "-doc" or the "Section" is "doc", the "doc" component is
       selected. If there is no matching component configured for the Grip repository, "main" is
       used. Section names themselves are read from the filter repository - i.e. set by the
       Debian ftp-master overrides.

switch_component

       Single routine to work out which components should be used for which sections.

AUTHOR

       Neil Williams, "<codehelp@debian.org>"

BUGS

       Please report any bugs or feature requests to the Debian Bug Tracking System using
       "reportbug emdebian-tools".

Known bugs

       (Otherwise known as a ToDo list.)

       The status of TDebs in the locale repository needs to be checked before generating more
       but this means changes in emgrip too so that tdebs can be skipped with a command line
       option. However, in normal operation, the package is only processed because it is out of
       date so the TDebs and other files need to be replaced anyway.

       "Architecture: all" are packages being continually reprocessed for several architectures.
       Originally this was because the package could contain translations which would need to be
       architecture-dependent in Emdebian. However, TDebs should be being generated only from
       source packages and this step probably needs to resolved. "reprepro" correctly handles
       such duplication, it is just a bit noisy when handling it and it adds to the time required
       by the process as a whole.

       Also need a general overview function that summaries all three repositories.