NAME¶
apt-grip - extend Emdebian Grip to add Debian packages on-the-fly
Synopsis¶
$ sudo apt-grip foo bar baz
$ sudo apt-grip -M http://ftp.fr.debian.org/debian/ foo bar baz
$ sudo apt-grip --clean-cache
Description¶
Emdebian Grip has a limited number of packages in the main repository,
principally to reduce the size of the apt cache data. On occassion, individual
packages from standard Debian need to be added to a single machine running
Emdebian Grip.
apt-grip has been written with that purpose in mind.
apt-grip requires DEB_VENDOR support in dpkg to determine how the package
should be "gripped". The default Vendor is "emdebian-grip"
but note the next section on the limitations of apt-grip if you plan to use it
on an unmodified Debian system.
The usual case is that the system has already been upgraded to Emdebian Grip
before
apt-grip is used.
Contact the debian-embedded@lists.debian.org mailing list for requests to add
packages to Emdebian Grip repositories directly.
Downloading the Packages files can take a reasonable amount of time, so to grip
a number of packages, either specify all packages in one command or use the
"--keep-cache" option for each run and use the
"--clean-cache" option at the end.
If the device running Grip has insufficient space to download and process the
package(s), run apt-grip on a different machine of the using the
"--build-only" and "--arch" options.
The processed archives will be in
/var/lib/apt-grip/output/ and can be
copied from there onto the device directly or by including the packages into a
locally accessible repository. Once installed on the Grip device use
"apt-grip -c" on the build machine to clear the cache.
"--keep-cache" is implied when "--build-only" is set.
Note also that, in common with the rest of Emdebian processing,
Install-Recommends is always turned off, so if you need a package that is only
recommended by packages in the list given to "apt-grip", that
package will need to be added to the list explicitly.
Limitations¶
Installing any package from repositories outside the normal apt sources
(especially if those packages are subsequently modified as in emgrip) will
list those packages as "local or obsolete" in package managers.
Converted packages cannot be upgraded without repeating the call to
"apt-grip" because "apt-get" does not know about the
temporary mirror that "apt-grip" used to download the packages. This
can cause problems if dependencies of such packages need to be upgraded. It is
possible that the main system "apt" will try to remove these local
packages in order to proceed with the main system upgrade.
The best option is to seek addition of such packages to the repository you use
for your main apt sources. (Use the
emdebian-grip-server package to
create your own repository.)
"Gripping" a package means making a new version (with the em1 version
suffix) with less files in the new package. See emgrip (1) for detailed
information on that process. Changing the version string means that some
dependencies need to be changed - particularly strict dependencies. This means
that
apt-grip could fail with some combinations of packages.
"apt-grip" uses the "--reinstall" option to
apt-get
to cope with some of these situations.
Strict dependency issues¶
If a source package builds multiple binary packages, where at least one package
has a strict dependency on one of the other binary packages and one of those
binary packages is already installed from Debian, it will be necessary to
install Grip versions of both the binary packages involved so that the strict
dependency can be satisfied.
Source: foo
Package: foo
Depends: bar (= 0.0.1)
Package: bar
$ sudo apt-grip foo bar
In the example above,
foo_0.0.1_amd64.deb will become
foo_0.0.1em1_amd64.deb and will be given a strict dependency on
"bar (= 0.0.1em1)" by
emgrip.
Default mirror¶
apt-grip uses "
http://ftp.uk.debian.org/debian/" as the default
Debian mirror. Use the -M|--mirrror option to change it.
SecureApt¶
Use the "--no-auth" option to allow the use of unauthenticated
repositories. Note that this disables authentication against all available
repositories.
Upgrading to Grip¶
Change your sources list from debian mirrors to the emdebian grip mirror.
e.g. for unstable:
deb http://www.emdebian.org/grip/ unstable main
(Emdebian Grip only supports Debian suites: unstable, sid, testing, squeeze,
stable, lenny, lenny-proposed-updates.)
Then update and upgrade:
$ sudo apt-get update
$ sudo apt-get clean
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade
(Note that
apt-get will usually report the ability to free several
hundred megabytes on your system when some of your Debian packages are
upgraded to Emdebian Grip but you still need enough room to actually download
and unpack the new packages.) Use "apt-get clean" after the upgrade
to recover more free space.
Grip components¶
Grip divides the archive further by creating new areas of the archive for
packages related to development, debugging, documentation or java, again to
reduce the final size of the cached package data on the system. If you want to
use "apt-grip" on your Emdebian Grip system, ensure that you add the
dev component to your apt sources:
deb http://www.emdebian.org/grip/ unstable main dev
Similarly for
doc,
debug and
java. Other components may be
added from time to time, so check the Emdebian website:
http://www.emdebian.org/grip/search.php
Add more components as required:
deb http://www.emdebian.org/grip/ unstable main dev debug java
Emdebian Baked¶
apt-grip has been extended to help generate packages for use with Emdebian
Baked. This has meant adding foreign architecture support as well as support
for ignoring the status of currently installed packages on the device running
apt-grip.
The difficult part of this process is managing updated packages and changed
dependencies. apt-grip can only help with Debian stable.
emdebian-grip has not been backported to Lenny, so your development machine must
be running Debian Squeeze or Sid (testing or unstable) to develop a Baked root
filesystem based on Lenny.
Example apt-grip command for Baked¶
$ sudo apt-grip -a mipsel -V emdebian-baked -S stable dash snmpd
Baked packages will then exist in /var/lib/apt-grip/output/, including all
dependencies of the specified packages. These can then be included into an
existing reprepro repository:
$ reprepro includedeb stable /var/lib/apt-grip/output/*.deb
If your repository is to support more than one architecture, ensure that you
remove or ignore the Architecture: all packages which have already been
processed by apt-grip:
$ sudo rm /var/lib/apt-grip/output*_all.deb
Then use the -A option to reprepro to only include the added architecture:
$ reprepro -A armel includedeb stable /var/lib/apt-grip/output/*_armel.deb
For more information, see the emdebian website:
http://www.emdebian.org/baked/
