1. SUSE Linux Enterprise Desktop Administration Chapter 14 Customize the Graphical Interface on SUSE Linux Enterprise Desktop 10

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

3. SUSE Linux Enterprise Desktop Administration Objective 1—Configure X, Xgl, and Compiz 3 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

4. SUSE Linux Enterprise Desktop Administration4 Figure 14-1 New SLED 10 Linux desktop

5. SUSE Linux Enterprise Desktop Administration Objective 1—Configure X, Xgl, and Compiz (continued) 5 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

6. SUSE Linux Enterprise Desktop Administration 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 6

7. SUSE Linux Enterprise Desktop Administration7 Figure 14-2 Activate 3D acceleration

8. SUSE Linux Enterprise Desktop Administration8 Figure 14-3 Activate SaX2 Configure X (continued)

9. SUSE Linux Enterprise Desktop Administration9 Figure 14-4 The YaST Graphics Card and Monitor module

10. SUSE Linux Enterprise Desktop Administration 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 10

11. SUSE Linux Enterprise Desktop Administration11 Table 14-1 Frequently used controls Activate Compiz (continued)

12. SUSE Linux Enterprise Desktop Administration Exercise 14-1: Activate Compiz (Optional, Depending on Hardware Support) In this exercise, you configure Compiz, provided the hardware supports it 12

13. SUSE Linux Enterprise Desktop Administration Objective 2—Customize 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 13

14. SUSE Linux Enterprise Desktop Administration 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 14

15. SUSE Linux Enterprise Desktop Administration15 Figure 14-5 The gconf-editor

16. SUSE Linux Enterprise Desktop Administration 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/gconf.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 16

17. SUSE Linux Enterprise Desktop Administration 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 17

18. SUSE Linux Enterprise Desktop Administration Objective 3—Define 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 18

19. 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 SUSE Linux Enterprise Desktop Administration Use GConf to Set Mandatory Preference Values 19

20. gconf-editor (continued) –Change existing mandatory preferences Start gconf-editor Then select File > 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 SUSE Linux Enterprise Desktop Administration Use GConf to Set Mandatory Preference Values (continued) 20

21. SUSE Linux Enterprise Desktop Administration 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 > More Applications > System > 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 21

22. SUSE Linux Enterprise Desktop Administration Use the Desktop Profile Editor (continued) Define a profile (continued) –When you are done, in the Editing Profile profilename window, select Edit > Changes –See Figure 14-7 –To make a change mandatory, click on the lock on the respective line –To save your profile, select Profile > Save The profile is saved in /etc/opt/gnome/desktop-profiles/ profilename.zip 22

23. SUSE Linux Enterprise Desktop Administration23 Figure 14-6 Add a new user profile Use the Desktop Profile Editor (continued)

24. SUSE Linux Enterprise Desktop Administration24 Figure 14-7 Editing profiles properties

25. SUSE Linux Enterprise Desktop Administration 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/desktop- profiles/users.xml –This, in turn, executes /opt/gnome/sbin/sabayon-apply For users with a profile, this command copies the files contained in the.zip file to the user’s home directory –A user can at least temporarily circumvent the settings marked as mandatory in the Profile Editor of Sabayon 25

26. SUSE Linux Enterprise Desktop Administration26 Figure 14-8 Assign profiles to users Use the Desktop Profile Editor (continued)

27. SUSE Linux Enterprise Desktop Administration 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 27

28. SUSE Linux Enterprise Desktop Administration 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 > GNOME > 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 28

29. SUSE Linux Enterprise Desktop Administration Lock Down the Desktop (continued) Use the Desktop Profile Editor (Sabayon) –Start the Desktop Profile Editor; then select Edit > 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 > 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 > Save and choose the user or users these settings should be applied to 29

30. SUSE Linux Enterprise Desktop Administration30 Figure 14-9 Using the Desktop Profile Editor

31. SUSE Linux Enterprise Desktop Administration31 Figure 14-10 Setting properties as mandatory Lock Down the Desktop (continued)

32. SUSE Linux Enterprise Desktop Administration 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 32

33. SUSE Linux Enterprise Desktop Administration Objective 4—Customize Applications This objective covers two examples of configuration settings that can be made available to all users: –OpenOffice.org 2.0 –Firefox 33

34. SUSE Linux Enterprise Desktop Administration 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 > Options > Language Settings > Language –Within a user’s home directory, the configuration directory for OpenOffice.org on SLED 10 is ~/.ooo-2.0 34

35. SUSE Linux Enterprise Desktop Administration 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 user’s home directory in /.ooo-2.0/user/template/ –If a user selects File > New > Templates and Documents > Templates, the user will find the company templates in a directory 35

36. SUSE Linux Enterprise Desktop Administration36 Figure 14-11 OpenOffice Templates and Documents OpenOffice.org 2.0 (continued)

37. SUSE Linux Enterprise Desktop Administration Firefox Firefox can be configured extensively via Edit > Preferences Several tabs cover various aspects of the configuration –See Figure 14-12 You can also access the preferences at about:config –See Figure 14-13 Changed values are stored in the home directory of the user in /.mozilla/firefox/ xxxxxxxx.default/prefs.js 37

38. SUSE Linux Enterprise Desktop Administration38 Figure 14-12 Firefox preferences

39. SUSE Linux Enterprise Desktop Administration39 Figure 14-13 Firefox about:config

40. SUSE Linux Enterprise Desktop Administration Objective 5—Control 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 40

41. SUSE Linux Enterprise Desktop Administration 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 >GNOME > Volume Manager –See Figure 14-14 41

42. SUSE Linux Enterprise Desktop Administration42 Figure 14-14 GNOME Volume Manager

43. SUSE Linux Enterprise Desktop Administration 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_manager 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 43

44. SUSE Linux Enterprise Desktop Administration 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: 44

45. SUSE Linux Enterprise Desktop Administration 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 45

46. SUSE Linux Enterprise Desktop Administration 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 46

47. SUSE Linux Enterprise Desktop Administration 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 47