blog/data/2014-04-23-isenkram.txt

   1 Title: Install hardware dependent packages using tasksel (Isenkram 0.7)
   2 Tags: english, debian, isenkram
   3 Date: 2014-04-23 14:50
   4
   5 <p>It would be nice if it was easier in Debian to get all the hardware
   6 related packages relevant for the computer installed automatically.
   7 So I implemented one, using
   8 <a href="http://packages.qa.debian.org/isenkram">my Isenkram
   9 package</a>.  To use it, install the tasksel and isenkram packages and
  10 run tasksel as user root.  You should be presented with a new option,
  11 "Hardware specific packages (autodetected by isenkram)".  When you
  12 select it, tasksel will install the packages isenkram claim is fit for
  13 the current hardware, hot pluggable or not.<p>
  14
  15 <p>The implementation is in two files, one is the tasksel menu entry
  16 description, and the other is the script used to extract the list of
  17 packages to install.  The first part is in
  18 <tt>/usr/share/tasksel/descs/isenkram.desc</tt> and look like
  19 this:</p>
  20
  21 <p><blockquote><pre>
  22 Task: isenkram
  23 Section: hardware
  24 Description: Hardware specific packages (autodetected by isenkram)
  25  Based on the detected hardware various hardware specific packages are
  26  proposed.
  27 Test-new-install: mark show
  28 Relevance: 8
  29 Packages: for-current-hardware
  30 </pre></blockquote></p>
  31
  32 <p>The second part is in
  33 <tt>/usr/lib/tasksel/packages/for-current-hardware</tt> and look like
  34 this:</p>
  35
  36 <p><blockquote><pre>
  37 #!/bin/sh
  38 #
  39 (
  40     isenkram-lookup
  41     isenkram-autoinstall-firmware -l
  42 ) | sort -u
  43 </pre></blockquote></p>
  44
  45 <p>All in all, a very short and simple implementation making it
  46 trivial to install the hardware dependent package we all may want to
  47 have installed on our machines.  I've not been able to find a way to
  48 get tasksel to tell you exactly which packages it plan to install
  49 before doing the installation.  So if you are curious or careful,
  50 check the output from the isenkram-* command line tools first.</p>
  51
  52 <p>The information about which packages are handling which hardware is
  53 fetched either from the isenkram package itself in
  54 /usr/share/isenkram/, from git.debian.org or from the APT package
  55 database (using the Modaliases header).  The APT package database
  56 parsing have caused a nasty resource leak in the isenkram daemon (bugs
  57 <a href="http://bugs.debian.org/719837">#719837</a> and
  58 <a href="http://bugs.debian.org/730704">#730704</a>).  The cause is in
  59 the python-apt code (bug
  60 <a href="http://bugs.debian.org/745487">#745487</a>), but using a
  61 workaround I was able to get rid of the file descriptor leak and
  62 reduce the memory leak from ~30 MiB per hardware detection down to
  63 around 2 MiB per hardware detection.  It should make the desktop
  64 daemon a lot more useful.  The fix is in version 0.7 uploaded to
  65 unstable today.</p>
  66
  67 <p>I believe the current way of mapping hardware to packages in
  68 Isenkram is is a good draft, but in the future I expect isenkram to
  69 use the AppStream data source for this.  A proposal for getting proper
  70 AppStream support into Debian is floating around as
  71 <a href="https://wiki.debian.org/DEP-11">DEP-11</a>, and
  72 <a href="https://wiki.debian.org/SummerOfCode2014/Projects#SummerOfCode2014.2FProjects.2FAppStreamDEP11Implementation.AppStream.2FDEP-11_for_the_Debian_Archive">GSoC
  73 project</a> will take place this summer to improve the situation.  I
  74 look forward to seeing the result, and welcome patches for isenkram to
  75 start using the information when it is ready.</p>
  76
  77 <p>If you want your package to map to some specific hardware, either
  78 add a "Xb-Modaliases" header to your control file like I did in
  79 <a href="http://packages.qa.debian.org/pymissile">the pymissile
  80 package</a> or submit a bug report with the details to the isenkram
  81 package.  See also
  82 <a href="http://people.skolelinux.org/pere/blog/tags/isenkram/">all my
  83 blog posts tagged isenkram</a> for details on the notation.  I expect
  84 the information will be migrated to AppStream eventually, but for the
  85 moment I got no better place to store it.</p>