blog/tags/sysadmin/sysadmin.rss

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   3         <channel>
   4                 <title>Petter Reinholdtsen - Entries tagged sysadmin</title>
   5                 <description>Entries tagged sysadmin</description>
   6                 <link>http://people.skolelinux.org/pere/blog/</link>
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   9         <item>
  10                 <title>Debian Jessie, PXE and automatic firmware installation</title>
  11                 <link>http://people.skolelinux.org/pere/blog/Debian_Jessie__PXE_and_automatic_firmware_installation.html</link>
  12                 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Debian_Jessie__PXE_and_automatic_firmware_installation.html</guid>
  13                 <pubDate>Fri, 17 Oct 2014 14:10:00 +0200</pubDate>
  14                 <description>&lt;p&gt;When PXE installing laptops with Debian, I often run into the
  15 problem that the WiFi card require some firmware to work properly.
  16 And it has been a pain to fix this using preseeding in Debian.
  17 Normally something more is needed.  But thanks to
  18 &lt;a href=&quot;https://packages.qa.debian.org/i/isenkram.html&quot;&gt;my isenkram
  19 package&lt;/a&gt; and its recent tasksel extension, it has now become easy
  20 to do this using simple preseeding.&lt;/p&gt;
  21
  22 &lt;p&gt;The isenkram-cli package provide tasksel tasks which will install
  23 firmware for the hardware found in the machine (actually, requested by
  24 the kernel modules for the hardware).  (It can also install user space
  25 programs supporting the hardware detected, but that is not the focus
  26 of this story.)&lt;/p&gt;
  27
  28 &lt;p&gt;To get this working in the default installation, two preeseding
  29 values are needed.  First, the isenkram-cli package must be installed
  30 into the target chroot (aka the hard drive) before tasksel is executed
  31 in the pkgsel step of the debian-installer system.  This is done by
  32 preseeding the base-installer/includes debconf value to include the
  33 isenkram-cli package.  The package name is next passed to debootstrap
  34 for installation.  With the isenkram-cli package in place, tasksel
  35 will automatically use the isenkram tasks to detect hardware specific
  36 packages for the machine being installed and install them, because
  37 isenkram-cli contain tasksel tasks.&lt;/p&gt;
  38
  39 &lt;p&gt;Second, one need to enable the non-free APT repository, because
  40 most firmware unfortunately is non-free.  This is done by preseeding
  41 the apt-mirror-setup step.  This is unfortunate, but for a lot of
  42 hardware it is the only option in Debian.&lt;/p&gt;
  43
  44 &lt;p&gt;The end result is two lines needed in your preseeding file to get
  45 firmware installed automatically by the installer:&lt;/p&gt;
  46
  47 &lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
  48 base-installer base-installer/includes string isenkram-cli
  49 apt-mirror-setup apt-setup/non-free boolean true
  50 &lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;
  51
  52 &lt;p&gt;The current version of isenkram-cli in testing/jessie will install
  53 both firmware and user space packages when using this method.  It also
  54 do not work well, so use version 0.15 or later.  Installing both
  55 firmware and user space packages might give you a bit more than you
  56 want, so I decided to split the tasksel task in two, one for firmware
  57 and one for user space programs.  The firmware task is enabled by
  58 default, while the one for user space programs is not.  This split is
  59 implemented in the package currently in unstable.&lt;/p&gt;
  60
  61 &lt;p&gt;If you decide to give this a go, please let me know (via email) how
  62 this recipe work for you if you decide to give it a go. :)&lt;/p&gt;
  63
  64 &lt;p&gt;So, I bet you are wondering, how can this work.  First and
  65 foremost, it work because tasksel is modular, and driven by whatever
  66 files it find in /usr/lib/tasksel/ and /usr/share/tasksel/.  So the
  67 isenkram-cli package place two files for tasksel to find.  First there
  68 is the task description file (/usr/share/tasksel/descs/isenkram.desc):&lt;/p&gt;
  69
  70 &lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
  71 Task: isenkram-packages
  72 Section: hardware
  73 Description: Hardware specific packages (autodetected by isenkram)
  74  Based on the detected hardware various hardware specific packages are
  75  proposed.
  76 Test-new-install: show show
  77 Relevance: 8
  78 Packages: for-current-hardware
  79
  80 Task: isenkram-firmware
  81 Section: hardware
  82 Description: Hardware specific firmware packages (autodetected by isenkram)
  83  Based on the detected hardware various hardware specific firmware
  84  packages are proposed.
  85 Test-new-install: mark show
  86 Relevance: 8
  87 Packages: for-current-hardware-firmware
  88 &lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;
  89
  90 &lt;p&gt;The key parts are Test-new-install which indicate how the task
  91 should be handled and the Packages line referencing to a script in
  92 /usr/lib/tasksel/packages/.  The scripts use other scripts to get a
  93 list of packages to install.  The for-current-hardware-firmware script
  94 look like this to list relevant firmware for the machine:
  95
  96 &lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
  97 #!/bin/sh
  98 #
  99 PATH=/usr/sbin:$PATH
 100 export PATH
 101 isenkram-autoinstall-firmware -l
 102 &lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;
 103
 104 &lt;p&gt;With those two pieces in place, the firmware is installed by
 105 tasksel during the normal d-i run. :)&lt;/p&gt;
 106
 107 &lt;p&gt;If you want to test what tasksel will install when isenkram-cli is
 108 installed, run &lt;tt&gt;DEBIAN_PRIORITY=critical tasksel --test
 109 --new-install&lt;/tt&gt; to get the list of packages that tasksel would
 110 install.&lt;/p&gt;
 111
 112 &lt;p&gt;&lt;a href=&quot;https://wiki.debian.org/DebianEdu/&quot;&gt;Debian Edu&lt;/a&gt; will be
 113 pilots in testing this feature, as isenkram is used to install
 114 firmware now.&lt;/p&gt;
 115 </description>
 116         </item>
 117
 118         <item>
 119                 <title>Scripting the Cerebrum/bofhd user administration system using XML-RPC</title>
 120                 <link>http://people.skolelinux.org/pere/blog/Scripting_the_Cerebrum_bofhd_user_administration_system_using_XML_RPC.html</link>
 121                 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Scripting_the_Cerebrum_bofhd_user_administration_system_using_XML_RPC.html</guid>
 122                 <pubDate>Thu, 6 Dec 2012 10:30:00 +0100</pubDate>
 123                 <description>&lt;p&gt;Where I work at the &lt;a href=&quot;http://www.uio.no/&quot;&gt;University of
 124 Oslo&lt;/a&gt;, we use the
 125 &lt;a href=&quot;http://sourceforge.net/projects/cerebrum/&quot;&gt;Cerebrum user
 126 administration system&lt;/a&gt; to maintain users, groups, DNS, DHCP, etc.
 127 I&#39;ve known since the system was written that the server is providing
 128 an &lt;a href=&quot;http://en.wikipedia.org/wiki/XML-RPC&quot;&gt;XML-RPC&lt;/a&gt; API, but
 129 I have never spent time to try to figure out how to use it, as we
 130 always use the bofh command line client at work.  Until today.  I want
 131 to script the updating of DNS and DHCP to make it easier to set up
 132 virtual machines.  Here are a few notes on how to use it with
 133 Python.&lt;/p&gt;
 134
 135 &lt;p&gt;I started by looking at the source of the Java
 136 &lt;a href=&quot;http://cerebrum.svn.sourceforge.net/viewvc/cerebrum/trunk/cerebrum/clients/jbofh/&quot;&gt;bofh
 137 client&lt;/a&gt;, to figure out how it connected to the API server.  I also
 138 googled for python examples on how to use XML-RPC, and found
 139 &lt;a href=&quot;http://tldp.org/HOWTO/XML-RPC-HOWTO/xmlrpc-howto-python.html&quot;&gt;a
 140 simple example in&lt;/a&gt; the XML-RPC howto.&lt;/p&gt;
 141
 142 &lt;p&gt;This simple example code show how to connect, get the list of
 143 commands (as a JSON dump), and how to get the information about the
 144 user currently logged in:&lt;/p&gt;
 145
 146 &lt;blockquote&gt;&lt;pre&gt;
 147 #!/usr/bin/env python
 148 import getpass
 149 import xmlrpclib
 150 server_url = &#39;https://cerebrum-uio.uio.no:8000&#39;;
 151 username = getpass.getuser()
 152 password = getpass.getpass()
 153 server = xmlrpclib.Server(server_url);
 154 #print server.get_commands(sessionid)
 155 sessionid = server.login(username, password)
 156 print server.run_command(sessionid, &quot;user_info&quot;, username)
 157 result = server.logout(sessionid)
 158 print result
 159 &lt;/pre&gt;&lt;/blockquote&gt;
 160
 161 &lt;p&gt;Armed with this knowledge I can now move forward and script the DNS
 162 and DHCP updates I wanted to do.&lt;/p&gt;
 163 </description>
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