The changes for Emdebian Grip do not appear to demand rebuilding the
package - indeed, if the goal is retaining functionality as close as
possible to Debian as possible, then rebuilding (let alone
cross-building) gets in the way.
http://www.emdebian.org/emdebian/flavours.html
Therefore, I'm experimenting with *not* rebuilding for Emdebian Grip,
just for Emdebian Crush. i.e. Emdebian Grip can be quickly and easily
implemented for Eee PC and similar devices, from existing packages and
mirrors. Whilst it is certainly possible to run emgrip on the target
machine, the expectation is that maintainers of local mirrors can opt to
run emgrip on incoming packages before inclusion into the mirror - as
well as filtering out packages that are simply not useful on the target
devices for such a mirror - in order to reduce the size of Packages.gz
and the consequent delays in loading the dpkg database. In essence,
setting up (and maintaining) an Emdebian Grip repository could be as
simple as setting up the -cross repository that Simon created.
Status: 50% complete
Objective: a separate source package - possibly taking the place of
dpkg-cross and possibly merged into dpkg-dev (before Squeeze).
Initial home: /usr/share/emdebian-tools/ in emdebian-tools 1.4.11
(unreleased - possibly before LinuxLive, most likely afterwards.)
http://linux.codehelp.co.uk/emdebian/man/emgrip.html
NAME
emgrip - converts a .deb to Emdebian Grip on-the-fly
Description
Converts a .deb package to Emdebian Grip by unpacking, pruning
particular classes of files (determined by DEB_BUILD_OPTIONS) and
repacking with a note in the description and the em1 version suffix.
emgrip is entirely architecture-agnostic, it can process any .deb for
any architecture on any architecture.
Copyright and Licence
Copyright (C) 2007-2008 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/>;.
Emdebian Grip
The idea here is based on dpkg-cross:
1. receive .deb as a command-line option
2. parse DEB_BUILD_OPTIONS (not fully functional yet)
3. unpack the .deb as dpkg-cross does
4. remove files as per DEB_BUILD_OPTIONS
5. repack the .deb with a suitable addition to the description
and an Emdebian version suffix.
6. build new .deb and a new .changes so that the
original source can be retained. (only .deb currently)
7. Include the gripped packages into a local mirror
to reduce the size of Packages.gz and the size of
the mirror itself. (only tested locally so far)
As few dependencies as possible - this script should become a new
package and have a new set of lintian checks to allow perl etc.
NO FUNCTIONAL CHANGES IN THE FINAL .DEB !
Also needs to handle tdebs and convert to Emdebian TDebs.
Future versions will also have to understand Dpkg Classes but until
those are implemented, this uses brute force.
Same package also needs dh_grip which can be added to all debian/rules
files just before dpkg-build .. or dh_builddeb and which does nothing in
the normal circumstance but does the same as emgrip *if* the
DEB_BUILD_OPTION "usegrip" is set or if the other DEB_BUILD_OPTION's are
set, like "nodocs" or "noessential".
DEB_BUILD_OPTIONS
nodocs
Remove all content in /usr/share/doc/*/ except the copyright
file and compress the copyright file itself.
noessential
Remove the 'Essential: yes' tag from DEBIAN/control - this
is a brute force removal, no additional dependencies are to
be generated (no patches) so care is needed here.
splittdeb
Generate Emdebian-type TDebs instead of Debian ones - one TDeb
per source per locale instead of one TDeb only per source
package. The TDebs generated need to be organised by locale
root in the repository. Priority and Section are overridden in
the Emdebian TDeb to 'extra' and 'misc' respectively.
usegrip
Combination flag that sets all DEB_BUILD_OPTIONS that emgrip
understands.
Currently, emgrip assumes that 'usegrip' is always set.
Field removal
Functional control fields are retained but the question arises:
Who defines functional?
Well, for the current purposes of Emdebian Grip, functional includes
only the following control fields:
Package
Source
Architecture
Priority
Section
Maintainer
Depends
Pre-Depends
Conflicts
Replaces
Description
Recommends is explicitly rejected, as is Suggests - the expectation
is that Emdebian Grip will disable Install-Recommends in apt anyway.
Note also that 'Essential' is not.
Currently, Installed-Size is also removed as it cannot yet be
recalculated and would be misleading if retained.
Homepage, VCS* and all X- control fields are dropped.
The net result is a (potentially) much cleaner dpkg database. A further
option to trim the description at a certain number of complete
paragraphs or to remove all long paragraphs could be added.
Alternatively, a hard limit on the number of lines could have a comment
appended: "Rest of description trimmed."
emgrip will be in /usr/share/emdebian-tools/ in 1.4.11 as development
continues after http://www.linuxexpolive.co.uk/
There is a functional version in Emdebian SVN.
http://buildd.emdebian.org/svn/browser/current/host/trunk/emdebian-tools/trunk/emgrip
$ dpkg-architecture -qDEB_BUILD_ARCH
amd64
$ ./emgrip -v /opt/working/dpkg-cross/test/wget_1.10.2-3_arm.deb
Taking a grip on: /opt/working/dpkg-cross/test/wget_1.10.2-3_arm.deb
Extracting /opt/working/dpkg-cross/test/wget_1.10.2-3_arm.deb
Extracting information from control file
Creating control file
Building wget_1.10.2-3em1_arm.deb in /tmp
dpkg-deb: building package `wget' in `/tmp/wget_1.10.2-3em1_arm.deb'.
$ debdiff /opt/working/dpkg-cross/test/wget_1.10.2-3_arm.deb /tmp/wget_1.10.2-3em1_arm.deb
[The following lists of changes regard files as different if they have
different names, permissions or owners.]
Files in second .deb but not in first
-------------------------------------
-rw-r--r-- root/root /usr/share/doc/wget/copyright.gz
Files in first .deb but not in second
-------------------------------------
-rw-r--r-- root/root /usr/share/doc/wget/AUTHORS
-rw-r--r-- root/root /usr/share/doc/wget/ChangeLog.README
-rw-r--r-- root/root /usr/share/doc/wget/MAILING-LIST
-rw-r--r-- root/root /usr/share/doc/wget/NEWS.gz
-rw-r--r-- root/root /usr/share/doc/wget/README
-rw-r--r-- root/root /usr/share/doc/wget/TODO.gz
-rw-r--r-- root/root /usr/share/doc/wget/changelog.Debian.gz
-rw-r--r-- root/root /usr/share/doc/wget/changelog.gz
-rw-r--r-- root/root /usr/share/doc/wget/copyright
-rw-r--r-- root/root /usr/share/info/wget.info.gz
-rw-r--r-- root/root /usr/share/locale/bg/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/ca/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/cs/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/da/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/de/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/el/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/en_GB/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/eo/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/es/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/et/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/eu/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/fi/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/fr/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/ga/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/gl/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/he/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/hr/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/hu/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/it/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/ja/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/nl/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/no/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/pl/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/pt_BR/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/ro/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/ru/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/sk/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/sl/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/sr/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/sv/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/tr/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/uk/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/vi/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/zh_CN/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/locale/zh_TW/LC_MESSAGES/wget.mo
-rw-r--r-- root/root /usr/share/man/man1/wget.1.gz
Control files: lines which differ (wdiff format)
------------------------------------------------
Description: retrieves files from the web {+(gripped)+}
[-Installed-Size: 1908-]
{+.+}
{+ This is a 'gripped' package. See emgrip (1)+}
Version: [-1.10.2-3-] {+1.10.2-3em1+}
$ ls -lh /opt/working/dpkg-cross/test/wget_1.10.2-3_arm.deb /tmp/wget_1.10.2-3em1_arm.deb
-rw-r--r-- 1 neil neil 602K 2007-08-14 17:23 /opt/working/dpkg-cross/test/wget_1.10.2-3_arm.deb
-rw-r--r-- 1 neil neil 109K 2008-10-20 21:44 /tmp/wget_1.10.2-3em1_arm.deb
(That figure is only slightly misleading - the locale files would be
processed as TDebs but then any one install would only install one or at
most half a dozen TDebs instead of being forced to install all 35
translation files (at an average 30kb each).)
There are *no* dependency changes so it would be difficult to use
busybox in this environment without changes to the current coreutils
package in Debian. There are no changes to the maintainer scripts
either, so perl is going to be needed during installation of the
gripped .debs. This makes Emdebian Grip quite a bit bigger than Emdebian
Crush but also quite a bit smaller than Debian. No precise figures at
this stage but on this amd64 box, /usr/share/doc/ is over
600Mb, /usr/share/man is 41Mb and /usr/share/locale is over 500Mb.
Emdebian Grip would drop the total of all those to just a few megabytes
in /usr/share/doc/ for copyright.gz files. (/usr/share/doc/*/copyright
on this box is 17Mb, uncompressed), saving over 1Gb, with virtually no
other changes except smaller files in /var/lib/dpkg/*
and /var/cache/apt/archives. The appeal for Eee PC and similar devices
is obvious. One of my tests will be to create an Emdebian Grip local
mirror for i386 containing things like xfce and iceweasel, suitable for
my Acer Aspire1 (I'll use the list of packages usually installed on the
Aspire as a baseline for the test).
These Gripped packages would need to be in a separate repository from
the Crushed packages currently available at
http://buildd.emdebian.org/emdebian unstable main
Possibly http://buildd.emdebian.org/grip unstable main ?
Comments?
--
Neil Williams
=============
http://www.data-freedom.org/
http://www.nosoftwarepatents.com/
http://www.linux.codehelp.co.uk/
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