SUSE Linux Enterprise Desktop Administration

1
SUSE Linux Enterprise Desktop Administration

• Chapter 14
• Customize the Graphical Interface on SUSE Linux
  Enterprise Desktop 10

2
Objectives

• Objective 1Configure X, Xgl, and Compiz
• Objective 2Customize the GNOME User Interface
• Objective 3Define Mandatory Settings with GConf
  and Desktop Profile Editor
• Objective 4Customize Applications
• Objective 5Control Mounting of CD-ROM, DVD, and
  USB Devices

3
Objective 1Configure X, Xgl, and Compiz

• SUSE Linux Enterprise Desktop 10 provides an
  entirely new Linux desktop experience
• Through its use of 3D effects made possible by
  Xgl and Compiz
• See Figure 14-1
• Xgl is a new X Server architecture layered on top
  of OpenGL
• Can perform intricate graphical operations
  noticeably faster than other available X Servers
  that do not use OpenGL

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Figure 14-1 New SLED 10 Linux desktop
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Objective 1Configure X, Xgl, and Compiz
(continued)

• Compiz is a combination of a window manager and a
  composite manager using OpenGL for rendering
• Window manager
• Allows the manipulation of the multiple
  applications and dialog windows that are
  presented on the screen
• Composite manager
• Allows windows and other graphics to be combined
  to create composite images, such as those used to
  create transparency effects

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Configure X

• YaST Graphics Card and Monitor Module
• Uses sax2 for the X configuration
• Activate 3D acceleration by checking the Activate
  3D Acceleration option
• See Figure 14-2
• sax2
• Possible to use sax2 directly, without YaST
• sax2 is best started from a text terminal in
  runlevel 3
• Avoids any possible interference with the
  currently running X session
• See Figures 14-3 and 14-4

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Figure 14-2 Activate 3D acceleration
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Configure X (continued)
Figure 14-3 Activate SaX2
9
Figure 14-4 The YaST Graphics Card and Monitor
module
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Activate Compiz

• Packages needed to activate Compiz
• compiz
• Xgl
• Xgl-hardware-list
• gnome-session
• libwnck
• Once 3D acceleration has been activated, log in
  as a normal user to GNOME and activate Compiz
• Select the Computer icon in the lower-left corner
  of the desktop, open the GNOME Control Center,
  and start the Desktop Effects control panel

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Activate Compiz (continued)
Table 14-1 Frequently used controls
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Exercise 14-1 Activate Compiz (Optional,
Depending on Hardware Support)

• In this exercise, you configure Compiz, provided
  the hardware supports it

13
Objective 2Customize the GNOME User Interface

• You can customize the GNOME user interface in
  various ways
• The system used for storing application
  preferences in GNOME is Gconf
• GConf provides a preferences database, similar to
  a simple file system
• Keys are organized into a directory hierarchy
• Each key is either
• A directory containing more keys
• A value that is contained in the gconf.xml file
  in a key directory

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User-Defined Settings

• When a user defines the settings for his or her
  workstation
• The settings are written to a gconf.xml file in
  a directory beneath /.gconf
• You can define settings using the gconf-editor
• Open a terminal window, type gconf-editor, and
  press Enter
• See Figure 14-5
• You can also use the gconftool-2 command-line
  tool to change the GConf setting

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Figure 14-5 The gconf-editor
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Default Values

• Default values are used for any preferences that
  are not set specifically by the user
• Default values are set in /etc/opt/gnome/gconf/gco
  nf.xml.defaults/
• Change default values
• You can change the systemwide default values
  using either gconf-editor or gconftool-2
• You must be logged in as root

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Exercise 14-2 Customize the GNOME User Interface

• In this exercise, you set the preference for the
  mouse click to single click to launch programs
  that have an icon on the desktop and change the
  default for the background image

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Objective 3Define Mandatory Settings with GConf
and Desktop Profile Editor

• You can set mandatory preferences using the
  following approaches
• Use GConf to set mandatory preference values
• Use the desktop profile editor
• Lock down the desktop

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Use GConf to Set Mandatory Preference Values

• gconf-editor
• To set or change mandatory settings, you must be
  logged in as root when you use gconf-editor
• Set preferences as mandatory for the first time
• Start gconf-editor
• Browse the tree to the key you want to set as
  mandatory and set it to the desired value
• Then select the entry with the right mouse
  button in the context menu, select Set as
  Mandatory

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Use GConf to Set Mandatory Preference Values
(continued)

• gconf-editor (continued)
• Change existing mandatory preferences
• Start gconf-editor
• Then select File gt New Mandatory Settings
• To remove a key from the mandatory preferences,
  right-click on the entry and select Unset Key
• gconftool-2
• When you use gconftool-2, the gconf-editor can be
  helpful to browse the configuration repository
  tree to find the correct key and its path

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Use the Desktop Profile Editor

• The Desktop Profile Editor (Sabayon package)
• Allows you as the administrator to set
  preferences on a per-user basis
• Define a profile
• Select Computer gt More Applications gt System gt
  Desktop Profile Editor
• You are prompted for the root password
• Select Add to add a profile and enter a name
• Select the name then select Edit
• See Figure 14-6

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Use the Desktop Profile Editor (continued)

• Define a profile (continued)
• When you are done, in the Editing Profile
  profilename window, select Edit gt Changes
• See Figure 14-7
• To make a change mandatory, click on the lock on
  the respective line
• To save your profile, select Profile gt Save
• The profile is saved in /etc/opt/gnome/desktop-pro
  files/ profilename.zip

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Use the Desktop Profile Editor (continued)
Figure 14-6 Add a new user profile
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Figure 14-7 Editing profiles properties
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Use the Desktop Profile Editor (continued)

• Assign profiles to users
• Select the profile and then Users in the User
  Profile Editor
• See Figure 14-8
• This information is stored in /etc/opt/gnome/deskt
  op-profiles/users.xml
• This, in turn, executes /opt/gnome/sbin/sabayon-ap
  ply
• For users with a profile, this command copies the
  files contained in the .zip file to the users
  home directory
• A user can at least temporarily circumvent the
  settings marked as mandatory in the Profile
  Editor of Sabayon

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Use the Desktop Profile Editor (continued)
Figure 14-8 Assign profiles to users
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Exercise 14-3 Set Mandatory Values for
Preferences

• In this exercise, you use the Desktop Profile
  Editor to set mandatory preferences
• Use the Desktop Profile Editor (Sabayon) to lock
  the screen of all users after five minutes of
  inactivity

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Lock Down the Desktop

• Use GConf
• The gconf-editor interface lists keys to lock
  down the desktop in the tree on the left under
  Desktop gt GNOME gt Lockdown
• To prevent users from changing these settings,
  you should configure them in the mandatory part
  of the GConf repository
• Use the Desktop Profile Editor (Sabayon)
• Offers some more options to restrict users

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Lock Down the Desktop (continued)

• Use the Desktop Profile Editor (Sabayon)
• Start the Desktop Profile Editor then select
  Edit gt Lockdown in the xnest window menu
• See Figure 14-9
• Select the items that you want to disable
• To make the settings mandatory, select Edit gt
  Changes in the menu of the xnest window and
  select the lock icon in front of the respective
  entries
• See Figure 14-10
• Save by selecting File gt Save and choose the user
  or users these settings should be applied to

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Figure 14-9 Using the Desktop Profile Editor
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Lock Down the Desktop (continued)
Figure 14-10 Setting properties as mandatory
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Exercise 14-4 Disable Access to the Command Line

• In this exercise, you use gconf-editor to disable
  access to the command line on the GNOME desktop
• Use gconf-editor to make the command line
  unavailable on the desktop

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Objective 4Customize Applications

• This objective covers two examples of
  configuration settings that can be made available
  to all users
• OpenOffice.org 2.0
• Firefox

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OpenOffice.org 2.0

• Language Settings
• Many different languages are available, but they
  are contained in separate packages
• To install a language, open a terminal window and
  enter, as root, yast2sw_single
• Search for Office and select the package for the
  desired language
• Then start OpenOffice.org and select Tools gt
  Options gt Language Settings gt Language
• Within a users home directory, the configuration
  directory for OpenOffice.org on SLED 10 is
  /.ooo-2.0

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OpenOffice.org 2.0 (continued)

• Templates
• Companies usually develop their own templates for
  company-specific documents
• OpenOffice.org looks for templates in
• Subdirectories of the systemwide
  /usr/lib/ooo-2.0/share/template/language/
  directory
• The users home directory in /.ooo-2.0/user/templa
  te/
• If a user selects File gt New gt Templates and
  Documents gt Templates, the user will find the
  company templates in a directory

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OpenOffice.org 2.0 (continued)
Figure 14-11 OpenOffice Templates and Documents
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Firefox

• Firefox can be configured extensively via Edit gt
  Preferences
• Several tabs cover various aspects of the
  configuration
• See Figure 14-12
• You can also access the preferences at
  aboutconfig
• See Figure 14-13
• Changed values are stored in the home directory
  of the user in /.mozilla/firefox/
  xxxxxxxx.default/prefs.js

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Figure 14-12 Firefox preferences
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Figure 14-13 Firefox aboutconfig
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Objective 5Control Mounting of CD-ROM, DVD, and
USB Devices

• To control the automatic mounting of media, you
  have to understand how to do the following
• Use the GNOME Volume Manager
• Disable Automatic Mounting of Media

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Use the GNOME Volume Manager

• The GNOME Volume Manager (gnome-volume-manager)
• Started automatically when the GNOME desktop is
  launched
• Monitors volume-related events and responds with
  a user-specified policy
• The GConf editor lists the available keys under
  Desktop gtGNOME gt Volume Manager
• See Figure 14-14

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Figure 14-14 GNOME Volume Manager
43
Disable Automatic Mounting of Media

• Various methods of configuration
• GConf and /etc/fstab
• Use gconftool-2 to set the automount_drives and
  automount_media keys in /desktop/gnome/volume_mana
  ger in the mandatory GConf repository to false
• Kernel modules
• To read from USB storage devices, the usb_storage
  kernel module is needed
• Prevent the module from being loaded by entering
  the following line in /etc/modprobe.conf.local

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Disable Automatic Mounting of Media (continued)

• Various methods of configuration (continued)
• Configure udev rules
• With udev, device files are created only for
  actually present devices
• udev is very flexible and can be configured by
  writing rules to .rules files in the
  /etc/udev/rules.d/ directory
• A rule to disable devices that require the
  usb_storage module could look like the following

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Disable Automatic Mounting of Media (continued)

• Various methods of configuration (continued)
• Remove the hardware
• Physically remove CD-ROM and DVD drives as well
  as USB ports
• Also prevents the computer from being booted from
  bootable CDs

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Summary

• Xgl and the Compiz window manager work with the X
  Window System and your KDE or GNOME desktop
  environment
• To configure your video graphics card and monitor
  for use with X, you can use YaST or sax2
• You can use GConf to customize the GNOME user
  interface for the system for individual users as
  well as lock down access to certain desktop areas
• To configure GConf, you can use gconf-editor,
  gconftool-2, or the GNOME Preferences panel

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Summary (continued)

• The Desktop Profile Editor can be used in
  addition to GConf to create custom desktop
  settings profiles for different user accounts
• Or lock down access to the desktop
• You can customize graphical applications using
  YaST, as well as configure program preferences,
  alter configuration files, and create templates
• To enhance security on a computer that has
  removable media devices, you should prevent
  regular users from mounting removable media